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A 1-year-old male neutered ferret (Mustela putorius furo) was evaluated for an abnormal left cubital joint. Radiographs demonstrated a proliferative osseous lesion of the left proximal antebrachium. Computed tomography confirmed a large thin-walled expansile osseous lesion of the left proximal radius and identified multifocal proliferative lesions of the axial spine, two of which caused spinal cord compression. A left forelimb amputation with total scapulectomy was performed. Histopathology revealed a well-demarcated mass with a thin rim of mature lamellar bone and a discontinuous cartilage cap covered by a perichondrial/periosteal membrane continuous with the adjacent bone. Findings were most consistent with an osteochondroma or osteochondromatosis (i.e., multiple cartilaginous exostoses, hereditary multiple exostoses). No evidence of malignant transformation was observed within this specimen. Three months post-surgery, verbal correspondence with the owner confirmed return to normal activity level and no emergence of neurological signs. Repeat examination and imaging were recommended., Competing Interests: Declaration of competing interest None., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Desmitis of the accessory ligament of the deep digital flexor tendon (ALDDFT) is a commonly reported injury. Despite the commonality of this injury, the literature is limited to small case series, with the reported success following treatment varying from 18% to 75%., Objectives: To identify the prognosis and factors associated with a return to work following ALDDFT injury., Study Design: Retrospective case series., Methods: Medical records of horses from four equine hospitals (January 2000 and December 2018) with a diagnosis of desmitis of ALDDFT were reviewed. Data retrieved included case detail, use, history, lameness treatment and follow-up. Success was defined as returning to work. Backward stepwise logistic regression was used to identify variables significantly associated with return to work., Results: Ninety-one horses were included. The mean age was 13.5 years (standard deviation 4.9 years). Thirty-four percent (28/91) of horses were sound at the initial presentation. Sixty-eight percent (62/91) of horses were managed using controlled exercise alone, 28% (29/91) were treated with intra-lesional injection, therapeutic ultrasound, extracorporeal shockwave therapy or desmectomy of the ALDDFT and 3% (3/91) were euthanased without treatment. Sixty-four percent (54/85) of horses returned to work. Horses that were lame at follow-up were less likely to return to work (odds ratio [OR] 107.93, 95% confidence interval [CI] 20.06-580.61, p < 0.001) than those that returned to soundness. Identification of adhesions on ultrasonography was also associated with having reduced odds for return to work when compared to horses without adhesions (OR 0.10, 95% CI 0.01-0.76, p = 0.03)., Main Limitations: Retrospective nature of the study, the potential of selection bias with regards to follow-up., Conclusion: Sixty-four percent (54/85) of horses returned to work following injury of the ALDDFT. Persistence of lameness and adhesion formation were significantly associated with a poor outcome., (© 2023 The Authors. Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.)

Objective: To describe the diagnosis, management, and outcome of a dog with a right distal radial osteochondroma that penetrated the ulna, causing expansile lysis and fracture., Animal: A 9-month-old entire female German Shorthaired Pointer., Clinical Presentation, Progression, and Procedures: The dog had a 2-month history of weight-bearing lameness of the right forelimb and a 2-week history of a progressively enlarging, firm swelling on the distolateral antebrachium. Computed tomography was used to characterize the lesion and for surgical planning., Treatment and Outcome: A distal ulnar ostectomy removed the affected ulnar segment, and the radial osteochondroma was excised with rongeurs. The dog was sound at 2, 16, and 45 weeks postoperatively. Radiographs at 45 weeks showed a persistent ulnar ostectomy gap with irregular but smoothly marginated edges and focal cortical irregularity at the site of radial osteochondroma excision. There was no evidence of osteochondroma recurrence., Clinical Relevance: This is a newly recognized presentation of an osteochondroma penetrating the cortex of an adjacent bone in a dog resulting in expansile lysis and cortical fracture. Computed tomography was important in diagnosis and surgical planning, and surgical treatment was successful in removing the osteochondroma and ulnar lesion. This case provides long-term radiographic and clinical follow-up after osteochondroma excision and contributes to the current knowledge on prognosis following osteochondroma excision in dogs.

An 8-year-old Portuguese Water Dog presented with a 5-month history of left forelimb lameness. There was palmar pain. Ultrasonography revealed enlargement of the left median nerve. Subsequent MRI also showed enlargement of the median nerve in the distal palmar to the mid-forearm region. Rapid intraoperative diagnosis suggested malignant peripheral nerve sheath tumors (MPNST) and a neurotomy was performed. The lameness had almost disappeared in 1 month after surgery. Recurrence occurred 26 months postoperatively and the forelimb was amputated. At 950 days after the neurotomy, radiography revealed lung metastasis, and the dog died 988 days after the neurotomy. Neurotomy for MPNST should be performed with caution until more information is available regarding methods for early detection, margin determination, and indication determination for neurotomy.

Objective: To evaluate the feasibility and limitations associated with a minimally invasive ultrasound-assisted cutting thread technique for tenotomy of the deep digital flexor tendon (DDFT) in horses., Study Design: Ex vivo study., Sample Population: Twenty cadaveric forelimbs., Methods: Forelimbs were placed on a jig to mimic a standing semiflexed position and the midmetacarpal region was prepared to perform tenotomy of the DDFT using a percutaneous technique with a cutting thread. For that purpose, the thread was placed percutaneously around the DDFT (first dorsally and then palmarly) with the aid of a curved 20 gauge spinal needle. Tendon palpation/manipulation and ultrasonographic assessment assisted thread placement. Procedure time and skin puncture size were recorded. Limbs were then dissected to evaluate the degree of DDFT transection and the presence of any iatrogenic lesions., Results: The DDFT was completely transected in all cases. Minor lesions of the superficial digital flexor tendon were found in 11/20 limbs and considered clinically irrelevant. However, the neurovascular bundle was damaged in 6/20 limbs (four limbs had nerve damage and two limbs had a nerve and either a palmar artery or vein damaged). The skin puncture hole sizes ranged from undetectable to 5 mm long. The average duration of the procedure was 7 min and 38 s (range: 4 min 56 s to 10 min 19 s)., Conclusion: A DDFT tenotomy can be performed reliably with a percutaneous cutting thread technique. However, refinement of the technique is required to minimize iatrogenic damage., Clinical Significance: The reported technique allows a DDFT tenotomy to be performed in a minimally invasive manner and has the potential to be clinically applicable., (© 2023 American College of Veterinary Surgeons.)

Medial coronoid disease (MCD) is a common disease often associated with thoracic limb lameness in medium- and large-breed dogs. The term MCD includes subchondral changes of the medial coronoid process (MCP), as well as pathologies of both cartilaginous surfaces. As there are only a few comprehensive and detailed studies on the trabecular structure of the medial coronoid, the goal of this study was to compare the trabecular structure of the ulnar trochlear notch of canine cadavers with and without MCD using different micro-computed tomographic (micro-CT) parameters. Fifty-eight elbow joints from 29 canine cadavers of MCD-predisposed and non-predisposed breeds (control group) were examined radiographically, macroscopically and by microcomputed tomography. The study included elbow joints of eight Labrador Retrievers (21.6-37 kg), seven Golden Retrievers (26.3-42 kg), seven Bernese Mountain dogs (31-47 kg) and seven dogs of non-predisposed breeds (19.7-52 kg) (control group). The final diagnosis of MCD was based on necropsy and micro-computed tomographic examinations. Micro-CT examinations were performed using XtremeCT II (Scanco Medical, Zurich, Switzerland) and the following parameters were examined: bone volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), trabecular number (Tb.N), connectivity density (Conn.D) and degree of anisotropy (DA). Twenty-four elbows of 44 elbows of the predisposed breeds (Labrador Retrievers, Golden Retrievers Bernese Mountain dogs) showed subchondral changes and lesions of the cartilage surfaces. The result of this study is a higher density (BV/TV) of the trabecular bone of the ulnar trochlear notch in elbows affected by MCD compared to the control group. The increased density due to trabecular reconstruction in the ulnar trochlear notch is likely the result of selectively increased loading during life., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest related to this report. The research was not financially supported. The experiment was approved by the Animal Ethics Committee of the Faculty of Veterinary Medicine, Ludwig-Maximilians-University, Munich, Germany. Material preparation, data collection and analysis were performed by Tim Glück, Yury Zablotski and Andrea Meyer-Lindenberg. All authors read and approved the final manuscript., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Objective: To identify and measure radiolucencies at the solear margin of the distal phalanx in radiographs of healthy and laminitic hooves., Sample: Clinical records and dorsoproximal-palmarodistal radiographs of equine forelimbs with radiological diagnoses of either laminitis (n = 40, L) or navicular syndrome (n = 40, NS)., Methods: Outlines of the radiolucent structures at the solar margin were drawn in ImageJ, and a customized novel plugin "Arteries Analyzer/ImageJ" was used for measurements. The diverging radiolucencies outside the terminal arc of the distal phalanx were differentiated as arterial channels (open at the solear margin) and ellipses (closed at the solear margin). Comparisons between L and NS, between distal phalanges with and without ellipses, and of arterial channels and ellipses in areas were compared using Wilcoxon and the Mann-Whitney U tests, respectively. The reliability and repeatability of the method were tested using Friedman's test., Results: Fewer arterial channels but more ellipses were identified in L than in NS. In phalanges with ellipses (n = 47), the number of ellipses and the number of arterial channels were negatively correlated (PCC -0.181, P = .224). The number of ellipses correlated positively with the severity of laminitis (PCC 0.495, P < .001; n = 80) and with the degree of rotation of the distal phalanx (PCC 0.392, P < .001; n = 80)., Clinical Relevance: The software tool successfully measured arterial channels and ellipses outlined by the evaluators. Results indicate that healthy arteries develop into pathological ellipses in laminitic feet. This may be used to complement the interpretation of radiographs and support clinical decision-making.

Objective. Spinal cord injury (SCI) leads to debilitating sensorimotor deficits that greatly limit quality of life. This work aims to develop a mechanistic understanding of how to best promote functional recovery following SCI. Electrical spinal stimulation is one promising approach that is effective in both animal models and humans with SCI. Optogenetic stimulation is an alternative method of stimulating the spinal cord that allows for cell-type-specific stimulation. The present work investigates the effects of preferentially stimulating neurons within the spinal cord and not glial cells, termed 'neuron-specific' optogenetic spinal stimulation. We examined forelimb recovery, axonal growth, and vasculature after optogenetic or sham stimulation in rats with cervical SCI. Approach. Adult female rats received a moderate cervical hemicontusion followed by the injection of a neuron-specific optogenetic viral vector ipsilateral and caudal to the lesion site. Animals then began rehabilitation on the skilled forelimb reaching task. At four weeks post-injury, rats received a micro-light emitting diode (µLED) implant to optogenetically stimulate the caudal spinal cord. Stimulation began at six weeks post-injury and occurred in conjunction with activities to promote use of the forelimbs. Following six weeks of stimulation, rats were perfused, and tissue stained for GAP-43, laminin, Nissl bodies and myelin. Location of viral transduction and transduced cell types were also assessed. Main Results. Our results demonstrate that neuron-specific optogenetic spinal stimulation significantly enhances recovery of skilled forelimb reaching. We also found significantly more GAP-43 and laminin labeling in the optogenetically stimulated groups indicating stimulation promotes axonal growth and angiogenesis. Significance. These findings indicate that optogenetic stimulation is a robust neuromodulator that could enable future therapies and investigations into the role of specific cell types, pathways, and neuronal populations in supporting recovery after SCI., (Creative Commons Attribution license.)

Background: Osteoarthritis (OA) is a disease of joint degeneration and impaired function. Muscle atrophy, fatty infiltration, and fibrosis are degenerative features of muscle injury and predict poor outcomes in some degenerative and exercise-related injuries. Patients with glenohumeral joint OA usually have rotator cuff muscle degeneration, even though the rotator cuff is intact. However, the mechanism and correlation between OA and degeneration of muscles around joints are still unknown., Methods: Forty-five 12-month-old C57BL/6J mice received a single injection of monoiodoacetic acid into the right glenohumeral joint. The sham group was injected with saline on the same day in the right glenohumeral joint. Three and 6 weeks after the operation, gait analysis was conducted to evaluate the function of the forelimb. Then, the shoulder joint and supraspinatus muscle were collected for histologic staining, reverse transcription quantitative polymerase chain reaction, and biomechanics test. Correlations between fat area fraction in muscle, percentage wet muscle weight change or Osteoarthritis Research Society International score, and gait analysis/muscle mechanics tests were assessed using Pearson's correlation coefficient or Spearman's correlation coefficient., Results: Compared with the sham group, the monoiodoacetic acid group developed significant glenohumeral joint OA and the supraspinatus muscle developed significant fatty infiltration and muscle atrophy. Shoulder function correlated with glenohumeral joint OA/rotator cuff muscle severity, weight loss, and fatty infiltration., Conclusion: In mice, glenohumeral joint OA can lead to rotator cuff degeneration and inferior limb function. The small animal model could be a powerful tool to further study the potential mechanisms between glenohumeral OA and rotator cuff muscle degeneration., (Copyright © 2022. Published by Elsevier Inc.)

Degeneration of the distal axon and neuromuscular junction (NMJ) is considered a key and early feature of the pathology that accompanies motor neuron loss in people with amyotrophic lateral sclerosis (ALS). The mutant SOD1 G93A mouse replicates many features of the disease, however the sequence of events resulting in degeneration of the neuromuscular circuitry remains unknown. Furthermore, despite widespread degenerative neuronal pathology throughout the spinal cord in this model, hindlimb motor function is lost before forelimb function. We investigated axons and NMJs in the hindlimb (gastrocnemius) and forelimb (extensor) muscles in the high copy number mutant SOD1 G93A xYFP (yellow fluorescent protein) mouse. We found that distal axonal and NMJ alterations were present prior to previously reported functional symptom onset in this strain. Indeed, increased branch complexity as well as colocalisation between pre- and post-synaptic markers indicated widespread early axonal and NMJ alterations in the hindlimb. Immunohistochemical analysis demonstrated that the colocalisation of the scaffolding proteins nestin, LRP-4, dystrophin and rapsyn were diminished before post-synaptic receptors in the gastrocnemius, and the degree of loss differed between proteins. Analysis of the forelimb muscle revealed axonal and NMJ degeneration at a late, post symptomatic stage, as well as novel differences in NMJ morphology, with reduced complexity. Furthermore, post-synaptic scaffolding proteins were preserved in the forelimb compared with the hindlimb. Analysis of protein levels indicated an increase in LRP-4, dystrophin and rapsyn in post symptomatic skeletal muscle that may suggest ongoing attempts at repair. This study indicates that axonal and NMJ degeneration in the SOD1 model of ALS is a complex and evolving sequence of events. We provide evidence that YFP can detect morphological and plastic alterations in the SOD1 G93A mouse, and that the pre- and post-synaptic integrity of the NMJ plays an important role in the pathogenic mechanisms of ALS. [ABSTRACT FROM AUTHOR]

Background: Digital flexor tendon sheath (DFTS) pathology is an important cause of lameness in horses. The outcome after surgical treatment is variable and depends on the exact diagnosis., Objectives: To (1) describe the prevalence of lesions associated with lameness caused by nonseptic DFTS tenosynovitis in a large population of German sports and pleasure horses; (2) determine the sensitivity and specificity of diagnostic imaging techniques for identifying lesions within the DFTS with tenoscopic diagnosis being the gold standard; (3) explore associations between tenoscopically diagnosed lesions and signalment, purpose, and limb affected; and (4) describe the outcome following DFTS tenoscopy with nonseptic DFTS tenosynovitis in this population., Study Design: Retrospective case series., Methods: Medical records of horses admitted for tenoscopic surgery of nonseptic DFTS tenosynovitis between 2011 and 2020 were reviewed. Follow-up information was obtained via telephone contact. Sensitivity and specificity of ultrasonography and contrast tenography were determined using tenoscopic diagnosis as gold standard and univariable analysis was used to explore associations between signalment, case history, and tenoscopic diagnosis., Results: Medical records from 131 horses were retrieved, of which 8 horses had bilateral disease and 6 horses were presented for tenoscopy on two separate occasions (3 for tenoscopy in the same limb, 3 in a different limb), thus, making a total of 145 limbs. Lesions were most commonly diagnosed in the deep (DDFT; n = 55 limbs) and superficial (SDFT; n = 55 limbs) digital flexor tendons. Manica flexoria (MF) lesions were detected in 44 limbs and palmar/plantar annular ligament (PAL) constriction in 99 limbs. In 36 limbs, only one structure within the DFTS was injured, whereas in 109 limbs a combination of lesions was noted, the most common being the combination of a SDFT lesion with PAL constriction. All affected limbs were examined with diagnostic ultrasonography; contrast tenography was performed in 86 limbs. For diagnosis of MF and DDFT tears, tenography was more sensitive (89% [confidence interval, CI: 65.4%-95.2%]; 72% [CI: 46.4%-89.3%], respectively) than specific (64% [CI: 52.5%-77.6%]; 53% [CI: 42.2%-73.3%], respectively) whereas ultrasonography was more specific (92% [CI: 84.5%-96.3%]; 92% [CI: 83.6%-96.0%]) with lower sensitivity (64% [CI: 47.7%-77.2%]; 54% [CI: 39.5%-67.9%]). For SDFT lesions, ultrasonography was highly specific (94% [CI: 86.9%-97.9%]) with lower sensitivity (66% [CI: 51.3%-77.4%]). Follow-up information following first surgery was obtained for 118 horses (132 limbs): 18 (15.3%) of 118 horses remained chronically lame, 40 (33.8%) performed at a reduced level and 60 (50.8%) performed at the same or higher level following rehabilitation after tenoscopy. Horses with DDFT lesions had the poorest outcomes with only 36.6% returning to the same or higher level of exercise., Main Limitations: Retrospective analysis of clinical records and subjective outcome assessment based on owner follow-up with potential recall bias. Findings on diagnostic imaging are impacted by many factors including equipment quality and operator expertise and experience., Conclusion: Diagnostic imaging techniques were complimentary and contrast tenography was sensitive and ultrasonography was specific for the diagnosis of MF and DDFT lesions. Following tenoscopic surgery for nonseptic tenosynovitis of the DFTS, approximately half the cases were able to return to preinjury level of exercise., (© 2022 The Authors. Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.)

Objectives: The aims of this study were to distinguish between behavioral compensation and behavioral recovery and to determine the role of stroke lesions and the optimal timing of rehabilitation in true recovery., Design: Single pellet reaching test has been performed to analyze both quantitative and qualitative measures of forelimb function in a stroke animal model with lesions in the motor cortex, somatosensory cortex, or sensorimotor cortex. The four gestures of compensatory movement patterns that comprised a reach were head lift, limb withdrawal, pellet chasing, and phantom grasp., Results: Functional recovery improved in all the stroke groups after rehabilitation ( P < 0.001). However, the compensatory movement patterns of the motor cortex and somatosensory cortex stroke groups initially increased and subsequently decreased ( P = 0.0054), whereas those of the sensorimotor cortex stroke group increased and persisted ( P = 0.0063). In the sensorimotor cortex stroke group, compensatory movement patterns significantly decreased when training was initiated 5 and 14 days after stroke ( P = 0.0083, P = 0.0226, respectively), while they increased and persisted when training was initiated 1 day after stroke., Conclusions: These findings suggest that true recovery by task-specific training after stroke depends, probably, on the lesion size and the timing of rehabilitation., Competing Interests: Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Case History: Dogs (n = 6) suffering from elbow-associated lameness for a median of 3.5 (min 2, max 12) months duration requiring arthroscopic exploration according to imaging results were prospectively included in this study., Clinical Findings: Dogs that met the inclusion criteria were of various breeds with a median body weight of 18 (min 13.2, max 34.5) kg and median age at presentation of 11 (min 6, max 96) months. Results of imaging modalities (radiographs and/or computed tomography (CT)) were consistent with developmental elbow disease in all of the dogs., Arthroscopic Findings: Feasibility of the needle arthroscopy procedure was first assessed in a preliminary cadaveric study. Disease-free cadaveric forelimbs (n = 12) were collected from adult dogs (n = 6) euthanised for reasons unrelated to the present study. Elbow exploration was performed, beginning with needle arthroscopy (1 mm, 0° angle scope) followed by standard arthroscopy (2.4 mm, 30° angle scope) through a medial approach. The ease of introduction, range of motion and the quality of visualisation were assessed subjectively and the presence of iatrogenic introduction lesions and extent of field of vision (assessed by the number of anatomical structures visualised) were scored and statistically compared. Needle arthroscopy allowed inspection of all structures at risk for medial/caudal compartment disease in all joints considering the occasional need for multiple portals. In the clinical setting, elbow exploration was found to be similar to that in cadaver joints in 4/6 dogs. The lower quality of vision provided by needle arthroscopy was a limitation of the technique, and 2/6 clinical cases required conversion to standard arthroscopy for full visualisation of the joint. No introduction lesions were noted with needle arthroscopy in either the cadaveric or clinical studies., Conclusions and Clinical Relevance: Needle arthroscopy allowed safe visualisation of all of the structures of the medial and caudal compartment in disease-free cadaveric elbows, suggesting that needle arthroscopy is an appropriate technique for diagnosis and assessment of lesions of developmental elbow disease. However, the low quality of vision provided by the 1 mm scope, and the small diameter of the sleeve, which limited fluid inflow, combined with fragility of the device were major drawbacks that prevented consistent full exploration of the joint and detailed lesion assessment in clinical situations. Improvement of the device is thus necessary before use of the technique in clinical practice can be recommended., Abbreviations: CCD: Caudal compartment disease; CT: Computed tomography; DED: Developmental elbow disease; DJD: Degenerative joint disease; LCL: Lateral collateral ligament; LCP: Lateral coronoid process; LHC: Lateral part of the humeral condyle; MCD: Medial compartment disease; MCL: Medial collateral ligament; MCP: Medial coronoid process; MHC: Medial part of the humeral condyle; MRI: Magnetic resonance imaging.

Objective: To compare the attenuation of the medial coronoid process (MCP) in dogs with and without arthroscopically confirmed evidence of medial coronoid disease (MCD)., Animals: The database at our institution was searched for cases with thoracic limb lameness, diagnosed with MCD by arthroscopic examination that had CT as part of their investigation and compared with a control group of elbow joints from cadavers euthanized for reasons unrelated to MCD. A total of 84 elbow joints were included that met these criteria., Procedures: Following CT, a standardized measurement of the MCP was obtained from apex to base and the mean attenuation, SD, and total area were recorded. A comparative measurement was obtained from the proximal radial cortex at the level of the nutrient foramen. Elbow joint arthroscopy was carried out using standard portals, and the modified Outerbridge score was (MOS) used to score elbow joint cartilage. Descriptive and inferential statistics were carried out using MLwiN and R., Results: Attenuation of the MCP was reduced in dogs with MCD compared with those with no MCD (P < .002). No significant differences were observed in the attenuation between categories of severity (MOS). There was good inter- and intraobserver agreement between measurements (intraclass correlation coefficient = 0.89 and 0.95, respectively)., Clinical Relevance: MCP attenuation is reduced in dogs with MCD compared with dogs with no evidence of MCD. This finding may be a useful tool for early detection of MCD, but there is no relationship with arthroscopic lesion severity.

Desmopathy of the collateral ligaments of the equine interphalangeal joint is caused by a combination of factors, including hoof shape, excessive loading and ground surface. This complex problem poses a diagnostic challenge due to the non-specificity of perineural analgesia and the limitations associated with the most popular imaging methods such as radiography and ultrasonography. The aim of this study was to retrospectively determine the prevalence of desmopathy of the collateral ligaments of the equine distal interphalangeal joint in Poland between 2016 and 2019, and to establish the frequency and type of the associated pathologies. Desmopathy of the collateral ligaments of the distal interphalangeal joint was diagnosed in 14% of 152 horses examined by magnetic resonance imaging (MRI). In 64% of the cases, other changes were observed in the equine digit, and in 36% of the cases, desmopathy was the only diagnosed problem. Desmopathy of the collateral ligaments is not a frequently reported pathology in the distal part of the equine limb. The diagnostic difficulties described in this article suggest that considerable caution should be exercised when formulating the final diagnosis, prognosis and treatment options., (Copyright© by the Polish Academy of Sciences.)

Foot imbalance and malalignment of the digits are common in horses. Angle and distance measurements performed on bones, joints and hoof wall on radiographs provide essential guidance for precise corrective trimming and shoeing. This study aimed to investigate, if selected standing low-field magnetic resonance (MR) images can be used to accurately measure dorsopalmar and lateromedial foot conformation parameters in comparison to the radiographic gold standard. Images of 100 horses referred for standing low-field MR examination were selected. Foot conformation angles and distances were measured and compared between radiographs and MR images. Measurements from most imaging sources were significantly different from each other. Moderate to high correlation of foot conformation angles between radiographs and MR images in the lateromedial and dorsopalmar planes was found, with exception of the proximal interphalangeal joint angle, where there was only moderate agreement between radiographs and the 5-plane MR pilot (0.47, P < .001) and between radiographs and the 3-plane MR pilot (0.4, P < .001), respectively. Measurement of foot conformation parameters from low-field MR images should be used with caution in clinical practice and acquisition of current foot radiographs immediately before or after MR examination should be considered to facilitate precise trimming and shoeing., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Pelvic limb movement disorders unrelated to lameness or proprioceptive ataxia have been described in horses for centuries. The two best described are Shivering and Stringhalt. Shivering is unique in that it is primarily apparent when horses are asked to walk backward, without affecting forward gaits until quite advanced. Horses exhibit abduction and either hyperflexion or marked hyperextension of one or both pelvic limbs when walking backward, resulting in a pause at the peak of the stride cycle and reluctance to move backward. Generally, Stringhalt differs from Shivering in that it produces consistent hyperflexion without abduction in forward gaits including walk and trot. This review will focus on the two most common pelvic limb movement disorders, Shivering and Stringhalt, their clinical presentation, differential diagnosis, etiopathology, and treatment., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Background: Orthopedic diseases involving the forelimb fetlock joint of horses other than those used in professional racing have not been widely reported in the literature. One of these problems is the exostosis on the proximal forelimb phalanx (P1), which has not been reported previously in Western Libya., Aim: The study aimed to investigate the prevalence of P1 exostosis in traditional equestrian horses (known locally as Sarj horses) of different breeds in Libya that participated in a special social event and described its clinical findings radiographic appearance., Methods: The current study involved 60 horses admitted to private veterinary clinics with varied fetlock orthopedic problems. The studied horses were aged between 6 and 11 years old and galloped on hard grounds. Clinical and radiographic examinations were carried out on all horses. Lateromedial radiographs for one or both forelimb fetlock joints were acquired for each horse., Results: Clinical examination revealed that 21 horses (35%) had hard non-painful swelling on the dorsal aspect of fetlock with joint stiffness during flexion. In 19 of them, the swelling was bilateral. No forelimb lameness was noticed. Radiographically, hard swelling was diagnosed as bone exostosis, with various sizes, on the proximo-dorsal aspect of P1. There was also a new bone formation on the disto-dorsal part of third metacarpal bone in two cases., Conclusion: This study has documented the first report on bone exostosis on the proximo-dorsal aspect of the forelimb proximal phalanx as a common problem in Sarj horses that galloped on hard grounds in Western Libya. Although this bone lesion did not cause lameness in all reported cases, further investigations are warranted to identify its histopathological nature, potential etiology, and proper treatment., Competing Interests: The authors declare that there is no conflict of interest.

Purpose: The aim of this study was to assess the effects of experimentally induced photothrombotic stroke on structural and mechanical properties of rat m. flexor carpi ulnaris., Methods: Two groups of Young-adult male Sprague-Dawley rats were measured: stroke (n = 9) and control (n = 7). Photothrombotic stroke was induced in the forelimb region of the primary sensorimotor cortex. Four weeks later, muscle-tendon unit and muscle belly length-force characteristics of the m. flexor carpi ulnaris, mechanical interaction with the neighbouring m. palmaris longus, the number of sarcomeres in series within muscle fibres, and the physiological cross-sectional area were measured., Results: Stroke resulted in higher force and stiffness of the m. flexor carpi ulnaris at optimum muscle-tendon unit length, but only for the passive conditions. Stroke did not alter the length-force characteristics of m. flexor carpi ulnaris muscle belly, morphological characteristics, and the extent of mechanical interaction with m. palmaris longus muscle., Conclusion: The higher passive force and passive stiffness at the muscle-tendon unit level in the absence of changes in structural and mechanical characteristics of the muscle belly indicates that the experimentally induced stroke resulted in an increased stiffness of the tendon., (© 2021. The Author(s).)

Induction of severe inflammatory arthritis in the collagen antibody-induced arthritis (CAIA) murine model causes extensive joint damage and pain-like behavior compromising analysis. While mild models are less severe, their reduced, variable penetrance makes assessment of treatment efficacy difficult. This study aimed to compare macroscopic and microscopic changes in the paws, along with central nervous system activation between a mild and moderate CAIA model. Balb/c mice ( n =18) were allocated to control, mild, and moderate CAIA groups. Paw inflammation, bone volume (BV), and paw volume (PV) were assessed. Histologically, the front paws were assessed for joint inflammation, cartilage damage, and pre/osteoclast-like cells and the lumbar spinal cord and the periaqueductal gray (PAG) region of the brain for glial reactivity. A moderate CAIA dose induced (1) significantly greater local paw inflammation, inflammatory cell infiltration, and PV; (2) significantly more osteoclast-like cells on the bone surface and within the surrounding soft tissue; and (3) significantly greater glial reactivity within the PAG compared with the mild CAIA model. These findings support the use of a moderate CAIA model (higher dose of monoclonal antibodies with low-dose lipopolysaccharide) to induce more consistent histopathological features, without excessive joint destruction.

A 9-year-old, male neutered old English Sheepdog was presented for further investigation of altered mentation, impaired vision, and hemineglect syndrome of 10 days duration. An MRI study of the brain revealed multifocal, contrast-enhancing intra-axial lesions that had a stippled hypointense appearance in all sequences but lacked evidence of a strong signal void on T2* images. Histological examination of the brain postmortem confirmed the lesions were metastases arising from an osteosarcoma, which was later identified in the right humerus. To the authors' knowledge, these MRI characteristics of osteosarcoma metastases in the canine brain have not been previously reported., (© 2019 American College of Veterinary Radiology.)

Strangulating hair mats in dogs are characterized as soft tissue injury secondary to chronically matted hair, which can encircle the extremities and constrict lymphatic tissue and local vasculature. As the tissue swells, the hair constriction tightens and may result in tissue necrosis and osseous changes secondary to ischemic necrosis. The objectives of this retrospective case series were to describe the radiographic characteristics of persistent hair mat strangulation in dogs, to identify clinical features that would distinguish between dogs with soft tissue lesions only and dogs with osseous changes and to describe the clinical outcome in these dogs. All dogs with clinically identified strangulating hair matting had radiographically identified soft tissues defects and over half of the limbs evaluated had osseous lesions including focal periostitis, bone remodeling, bone atrophy, lysis of bone, and occasionally subluxation of joints. Chronically matted hair and strangulating hair mats in dogs are recognized by veterinarians as a medical finding in animal neglect. The osseous features of strangulating hair mats have not been described in the veterinary medical literature. This study describes the clinical features and radiographic characteristics of strangulating hair mats., (© 2020 American College of Veterinary Radiology.)

A 6-y-old, 3.5-kg, spayed female Toy Poodle was presented with left forelimb lameness of 2-d duration. Two months before the initial presentation, radiography showed osteolysis of the medial epicondyle of the left humerus, and the left forelimb was amputated. Grossly, the articular villi of the elbow joint were markedly thickened, and the articular cartilage surfaces of the distal humerus and proximal radius had partial erosion. Histologically, granulomatous arthritis and osteomyelitis characterized by the presence of abundant macrophages containing numerous fungi were observed. ITS and β-tubulin sequences amplified from the isolate from the specimen were 100% and 99% identical to type strain UTHSC D16-145 T of Talaromyces georgiensis , respectively. Canine osteoarthritis caused by T. georgiensis has not been reported previously, to our knowledge.

An 8 yr old male castrated hound presented for a left distal ulnar osteosarcoma. Staging (computed tomography and nuclear scintigraphy) did not reveal any metastases. A limb-sparing ulnectomy with local adjunctive carboplatin in a poloxamer copolymer gel (poloxamer 407) was performed. The patient recovered without complications after surgery. No wound healing complications or adverse effects occurred after local use of carboplatin in poloxamer 407. The local recurrence-free interval was 296 days from surgery, and the survival time was 445 days from initial diagnosis. This is the first report in the veterinary literature of using poloxamer 407 as a carrier for local delivery of chemotherapeutic drugs in a clinical patient., (© 2020 by American Animal Hospital Association.)

Background: In this 4-year prospective observational study, all elbows in a dysplasia screening program including 14,073 dogs were studied using radiographs in two projections. Elbows were evaluated for the presence of medial humeral epicondylar lesions or discreet calcified structures and were described as they appeared. The age, breed, and sex of affected dogs were recorded. The prevalence for each lesion was calculated exclusively on breeds where the number of radiographed dogs exceeded 500., Results: Medial humeral epicondylar lesions or medial discreet calcified structures were diagnosed in 183 dogs and 211 elbows. The prevalence of true Flexor enthesopathy (FE) in this Norwegian population of mainly young, large breed dogs was calculated to be approximately 1.4 per 1000 dogs and varied by breed. Also, the prevalence of the other lesions varied considerably by breed. The most common finding was discreet calcified structures, termed medial ossified structures (MOS) (0.7%). In elbows affected with fragmented medial epicondyles (FME) (0.07%) and especially FE (0.14%), the degree of periarticular new bone formation (PNBF) was increased when compared to unaffected elbows. In joints affected with MOSs or medial lucent lesions MLLs (0.25%), there was no difference in the presence or degree of PNBF compared to unaffected joints, even in older dogs., Conclusions: The prevalence of medial humeral epicondylar lesions and MOSs differs considerably among dog breeds. Elbow joints with FMEs and particularly FE had a highly increased presence and degree of PNBF compared to joints without these lesions. Elbow joints with MOSs or MLLs did not have an increased presence or degree of PNBF compared to joints without these lesions.

Objective: To evaluate the effect of sedation or general anesthesia (GA) on elbow goniometry and thoracic limb circumference (TLC) measurements in dogs with elbow osteoarthritis (OA)., Study Design: Prospective study., Animals: Twenty-four client-owned dogs with radiographically confirmed elbow OA., Methods: Elbow goniometry and TLC measurements were made before and after either sedation or GA by using a hand-held goniometer and spring tension measuring tape, respectively. Observers were not allowed to review their pre-sedation or pre-GA measurements at the time of obtaining measurements on dogs under sedation or GA. Mixed analysis of variance models were used to compare elbow goniometry and TLC measurements before and after sedation or GA., Results: Eleven and thirteen dogs were included in the sedation and GA groups, respectively. Mean elbow flexion decreased by 5° and 3° and mean elbow extension increased by 6° and 2° under sedation and GA, respectively. Total range of motion increased by 11° under sedation and by 5° under GA. Each of these changes was statistically significant (P < .05) except elbow extension under GA (P = .129). Sedation and GA did not influence TLC measurements (P > .05)., Conclusion: Sedation or GA led to slight and similar increase in elbow flexion and extension but did not influence TLC measurements in dogs with elbow OA., Clinical Significance: Sedation or GA can cause slight alterations to goniometric measurements in canine elbows with OA. The protocols used in this study for sedation and GA seem interchangeably acceptable for goniometry and TLC measurements in dogs with elbow OA., (© 2020 American College of Veterinary Surgeons.)

Elbow incongruity is a form of elbow dysplasia that causes osteoarthritis, pain, and lameness, and it is common in chondrodystrophic dog breeds. The objective of this retrospective secondary analysis study was to evaluate the intra- and interobserver repeatability of a novel radiographic incongruity grading system for assessing elbow incongruity in three chondrodystrophic dog breeds-the dachshund, Skye Terrier, and Glen of Imaal Terrier. We conducted an observer agreement study that included 220 mediolateral antebrachial radiographs from 110 dogs with the elbow in 90° flexion. The radiographs were independently assessed by three observers at three time points, using a four-stepped grading scale. The proportion of agreement and Kappa coefficient were calculated. Both the intra- and interobserver proportions of agreement were substantial when three grades were required to be identical (.705-.777 and .609, respectively), and almost perfect for two identical grades (.991-1.000 and .991, respectively). Some differences in repeatability between breeds were noted; specifically, the intraobserver repeatability was higher in the dachshund, and the interobserver repeatability was lower in the Glen of Imaal Terrier. Our study showed that the radiographic imaging protocol and incongruity grading system have high repeatability when assessing elbow incongruity in chondrodystrophic dog breeds., (© 2020 American College of Veterinary Radiology.)

Background: Musculoskeletal disorders can result from prolonged repetitive and/or forceful movements. Performance of an upper extremity high repetition high force task increases serum pro-inflammatory cytokines and upper extremity sensorimotor declines in a rat model of work-related musculoskeletal disorders. Since one of the most efficacious treatments for musculoskeletal pain is exercise, this study investigated the effectiveness of treadmill running in preventing these responses., Methods: Twenty-nine young adult female Sprague-Dawley rats were used. Nineteen were trained for 5 weeks to pull a lever bar at high force (15 min/day). Thirteen went on to perform a high repetition high force reaching and lever-pulling task for 10 weeks (10-wk HRHF; 2 h/day, 3 days/wk). From this group, five were randomly selected to undergo forced treadmill running exercise (TM) during the last 6 weeks of task performance (10-wk HRHF+TM, 1 h/day, 5 days/wk). Results were compared to 10 control rats and 6 rats that underwent 6 weeks of treadmill running following training only (TR-then-TM). Voluntary task and reflexive sensorimotor behavioral outcomes were assessed. Serum was assayed for inflammatory cytokines and corticosterone, reach limb median nerves for CD68+ macrophages and extraneural thickening, and reach limb flexor digitorum muscles and tendons for pathological changes., Results: 10-wk HRHF rats had higher serum levels of IL-1α, IL-1β and TNFα, than control rats. In the 10-wk HRHF+TM group, IL-1β and TNFα were lower, whereas IL-10 and corticosterone were higher, compared to 10-wk HRHF only rats. Unexpectedly, several voluntary task performance outcomes (grasp force, reach success, and participation) worsened in rats that underwent treadmill running, compared to untreated 10-wk HRHF rats. Examination of forelimb tissues revealed lower cellularity within the flexor digitorum epitendon but higher numbers of CD68+ macrophages within and extraneural fibrosis around median nerves in 10-wk HRHF+TM than 10-wk HRHF rats., Conclusions: Treadmill running was associated with lower systemic inflammation and moderate tendinosis, yet higher median nerve inflammation/fibrosis and worse task performance and sensorimotor behaviors. Continued loading of the injured tissues in addition to stress-related factors associated with forced running/exercise likely contributed to our findings.

Objective:  Computed tomography (CT) is used complementarily to radiography for the evaluation of medial coronoid disease (MCD). We hypothesized that a slice thickness > 2 mm would significantly affect the image quality and detection of fragmentation of the medial coronoid process. This study aimed to assess CT features indicating direct and indirect evidence of MCD in 168 CT studies with slice thicknesses of 1-, 2- and 3 mm., Materials and Methods:  The CT studies were blinded in terms of CT slice thickness and patient data and randomly assessed by two independent observers. All dogs underwent arthroscopic evaluation of the elbow joints. Both observers were unaware of the arthroscopic findings., Results:  Notably, blurring of the bone contour ( p  = 0.0001) was significantly influenced by slice thickness; here, a 1-mm thickness yielded a predominantly sharp and well-defined bone contour (observer 1, 91%; observer 2, 79%), whereas 2- (observer 1, 39.3%; observer 2, 56.3%) and especially 3-mm slice thicknesses yielded blurred margins with significantly reduced sharpness (observer 1, 0%; observer 2, 12.5%). The 1-mm slice thickness also yielded the highest fragment detection rate (observer 1, 55.4%; observer 2, 60.4%). Furthermore, the detection of fragment positions and of single fragments and fissures differed substantially with slice thickness., Clinical Relevance:  The findings of this study support the hypothesis that a CT slice thickness of ≥ 2 mm significantly affects fragment detection. In conclusion, a CT slice thickness of at least 1 mm is recommended for the assessment of MCD of the canine elbow., Competing Interests: None declared., (Georg Thieme Verlag KG Stuttgart · New York.)

Objective: To report demographic characteristics of a contemporary population of dogs with appendicular osteosarcoma and assess the relationship between demographic characteristics, site distribution, and phylogenetic breed clusters., Design: Retrospective case series., Methods: A search of the Veterinary Medical Database was performed for dogs with appendicular osteosarcoma as a new diagnosis. Entries were reviewed for the sex, neuter status, age at diagnosis, breed, affected limb, and tumor location. The reported breed for purebred dogs was used to categorize each dog into one of five phylogenetic groups based on microsatellite analysis., Results: 744 client-owned dogs were included in the study. Study dogs were represented by a male-to-female ratio of 0.95:1.0, the majority of which (80.9%) were neutered. Most dogs were diagnosed between 7-10 years of age. The majority (77.8%) of dogs were large or giant-breed dogs. Purebred dogs comprised 80.4% of the population. The most common purebred breed affected by OS was the Rottweiler (17.1%). The most common phylogenetic group represented was Mastiff-Terrier (M-T, 26.3%). OS was more commonly located in the forelimb (64.2%) versus the hindlimb (35.8%), and the humerus was the most common site (20.9%). The distribution of age groups and tumor locations were significantly different between phylogenetic clusters. The distribution of age groups and neuter status were significantly different between size groups., Conclusions and Significance: The demographic data of canine appendicular OS are similar to previous reports. The data on phylogenetic associations can guide future studies aimed at evaluating the genomic mutations that contribute to OS development and its biological behavior., Competing Interests: The authors have declared that no competing interests exist.

Background: Medial coronoid process disease is the most common manifestation of canine developmental elbow disease which can progress to a more severe medial compartment disease (MCompD) characterized by full-thickness cartilage loss of the medial coronoid process and the medial humeral condyle. Among others, the "Canine Unicompartmental Elbow" (CUE) has been reported to be an effective treatment strategy for MCompD, with full in 47.6% and acceptable function in 43.7% at 6 months or later of follow-up., Aim: To report on our clinical experiences with the CUE system using the caudo-medial approach in terms of both complications and functional outcome., Methods: Medical records of dogs that underwent CUE procedure using a caudo-medial approach over a 3-year period were retrospectively reviewed. This covered epidemiological data, bi-planar radiographs, subjective gait analysis, owner questionnaire, surgical reports, as well as second-look arthroscopic findings when available., Results: In total, 52 CUE procedures were performed in 44 dogs with a median age of 8.0 years (IQ: 5.0-10.0) and a median bodyweight of 31.9 kg (ranging 20-48 kg) at the surgery. Four cases never return for follow-up, but were included in the analysis to increase the number of cases with pre- and intra-operative data. Mean follow-up time available for the remaining 48 cases was 7.1 (SD: 5.2) months. Radiographic derived implant positioning and alignment proved to be satisfactory in the sagittal plane but parallelism in the frontal plane was only present in three cases. Second-look arthroscopy in five cases with delayed or disappointing functional improvement showed evidence of implant-related contact lesions and progressive erosion of the medial coronoid area in three elbows. Overall, complications occurred in 11 cases (21%), being major in eight (15%) and minor in three (6%). Major complications included refractory pain and lameness 6 to 12 months postoperatively in five cases. At last follow-up, 12 cases (25%) were considered to have full function, 35 cases (73%) acceptable function, and in one case, the function was considered unacceptable. As the only variable related to functional outcome, age had a negative predictive value for full function., Conclusion: The CUE procedure appears to be an effective treatment option for patients with MCompD. Older dogs might be at risk of having an inferior clinical outcome when compared to young patients. The reason for this is unknown and will have to be evaluated in future studies. Compared to a CUE case series of 103 elbows operated through a medial approach, using a caudo-medial approach decreased the incidence of approach-related complication. Nevertheless, the functional outcome in the current case series was less favorable than previously reported. These conflicting findings as well as the occurrence of potentially implant mechanical conflict at the medial joint compartment despite CUE warrants further studies., Competing Interests: Four of the authors are involved in CUE training courses and paid consultants of Arthex Vet Systems. Neither of the authors receives any royalties related to sales of CUE implants or instrumentation. No financial support in any form was provided in relation to the study.

Fluorine-18-fluoro-2-deoxy-d-glucose positron emission tomography (FDG PET) provides physiologic images of tissues based on their glucose metabolism. The combination of FDG PET and CT (FDG PET-CT) has been utilized in human musculoskeletal imaging to localize soft tissue lesions, however, this modality has not been thoroughly investigated for the diagnosis of canine lameness. This prospective, descriptive study evaluated FDG PET-CT findings in 25 client-owned dogs with inconclusive origin of thoracic or pelvic limb lameness (thoracic limb n = 15/25, 60%; pelvic limb n = 6/25, 24%; and combination of both limbs n = 4/25, 16%). We hypothesized that FDG PET-CT would aid the detection of soft tissue lesions not visible with other imaging modalities. Combined FDG PET-CT detected soft tissue lesions in 40% (n = 10/25) and osteoarthritis in 64% (n = 16/25) of the patients. FDG PET detected more soft tissue lesions than contrast-enhanced CT (n = 15/15, 100% and n = 12/15, 80%, respectively), while CT identified more osteoarthritis lesions than FDG PET (n = 26/26, 100% and n = 18/26, 69%, respectively). The three imaging-diagnoses based on the FDG PET component included the following: flexor carpi ulnaris muscle tear, psoas major myopathy, and tarsal desmopathy. No diagnosis for the lameness was obtained in three dogs. Findings supported FDG PET-CT as a useful adjunct imaging modality for detection of certain soft tissue injuries of the musculoskeletal system. Combined FDG PET-CT should be considered for cases where the cause of lameness is thought to be of soft tissue origin and cannot be diagnosed by conventional means., (© 2019 American College of Veterinary Radiology.)

Navicular syndrome, a common cause of equine forelimb lameness, is associated with pathological changes in the navicular bone. Consequently, administration of bisphosphonates (BPs) has been advocated in order to modify the rate of bone turnover. The present study aimed to assess the clinical efficacy of intramuscularly administered clodronic acid for the treatment of 11 horses with clinical and radiographic findings compatible with navicular syndrome. Magnetic resonance imaging was performed in 5 of the 11 horses. The animals were treated with an intramuscular dose of clodronic acid of 765 mg/horse, administered over three separate injection sites. Before and at 7, 30 and 90 days after treatment, horses were subjected to lameness and accelerometric evaluations. A clinical improvement was observed in 6 of the 11 horses. These 6 horses showed a mean reduction of two degrees in lameness score. Accelerometry in these horses revealed increased velocity, stride length, stride regularity and dorsoventral displacement of the gravity of centre together with a reduction in stride frequency, suggesting a gait improvement. This study demonstrates that intramuscular clodronic acid can be useful for lameness reduction in some horses with navicular syndrome., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Laminitis is associated with failure of the suspensory apparatus of the distal phalanx (SADP) connecting the distal phalanx to the hoof wall. The specific aim of this study was to examine in vitro whether thinning of the hoof wall leading to increased deformability influences the damage of the laminar tissue created by loading of the hoof. Paired cadaver forelimbs from twelve horses were used. For each pair, the hoof wall from one hoof was thinned by 25%; this was ascertained by radiography. The contralateral hooves were used as controls. In a material testing machine, hooves were loaded in a proximodistal direction at 0.5mm/s until a cut-off value of 8kN or 14mm was reached. Afterwards, samples of the SADP were taken for histology. Image-based evaluation of the destruction of the SADP was performed using quantitative histogram analysis. Additionally, three examiners masked to treatment (trimmed/untrimmed) qualitatively evaluated SADP destruction. During hoof loading with forces from 0.5 to 1.8 times the body mass of the donor horses, hooves with thinned hoof wall underwent significantly more deformation (P<0.05). Quantitative histogram analysis detected a shift to higher brightness values and a higher pixel intensity in control hooves, representing disruption in the histologic analysis. Qualitative evaluation of histology sections showed significantly more disruption of the SADP in untrimmed hooves (P=0.03). These results confirm the hypothesis that reduced hoof wall thickness can decrease disruption of laminar tissue in vitro, thus supporting the evaluation of hoof wall reduction as a prophylactic measure in horses at imminent risk of SADP failure., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Feline leishmaniasis (FeL) is an emerging infectious disease of cats caused by Leishmania infantum with global distribution. This study investigated the cause of chronic progressive cutaneous lesions in two cats from Central-west Brazil by using cytological, histopathologic, and immunohistochemical (IHC) analyses. Clinically, both cats had ulcerative cutaneous lesions at the nasal planum and ear resulting in a tentative diagnosis of squamous cell carcinoma (SCC). Moreover, both cats had varying degrees of onychogryphosis. However, cytology revealed chronic inflammatory reactions associated with intralesional amastigotes; histopathology confirmed chronic ulcerative dermatitis associated with intralesional and intracytoplasmic parasitic organisms consistent with amastigotes of Leishmania spp. within histiocytes. The IHC assay demonstrated that the intralesional parasitic structures identified by cytology and histopathology were immunoreactive to antigens of Leishmania spp., confirming the participation of this infectious disease agent in the development of the cutaneous lesions of these cats. The observation of onychogryphosis must be highlighted, since this lesion is frequently observed in dogs with visceral leishmaniasis but is underreported in FeL. Collectively, the pathologic and IHC findings of the chronic cutaneous disease confirmed active infections due to Leishmania spp. in these cats. Additionally, FeL with associated lesions to the ear and nasal planum must be considered as differential diagnosis for SCC in cats., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objective: To determine the prevalence of surgical site infection (SSI) after internal fixation and to identify risk factors for SSI and nonsurvival., Study Design: Retrospective study., Animals: One hundred fifty-five horses with long bone fractures or arthrodesis treated by internal fixation at 1 hospital between 2008-2016., Methods: Signalment, diagnosis, surgical repair, surgeon, surgical time, antimicrobial use, SSI onset, bacterial identification, and adjunct treatments were recorded. Perioperative variables were analyzed to identify risk factors associated with outcomes., Results: Surgical-site infection was reported in 22 of 155 (14.2%) horses, which is lower than what has been previously reported (P = .003). Horses with fetlock arthrodesis or ulnar fracture were more likely to develop SSI. Local prophylactic antimicrobial therapy was associated with an increased risk of SSI. Horses with SSI were 12 times (P < .0001) less likely to survive to discharge than horses without SSI. Horses with a fetlock or carpal arthrodesis or those with radial/humeral/femoral fractures were less likely to survive. No association was identified between open fractures, open reduction and internal fixation, or surgical times and SSI., Conclusion: The prevalence of SSI in this population was lower than what has been previously reported. Horses with fetlock or carpal arthrodesis or radial/humeral/femoral fractures were at increased risk for SSI and/or nonsurvival to discharge. A protective role of local antimicrobial therapy for SSI could not be established., Clinical Relevance: The impact of SSI on outcomes of cases of equine internal fixation remains substantial. Identification of cases at higher risk of SSI should influence surgical technique, postoperative management, and early intervention when SSI is suspected. Additional investigation is warranted regarding local antimicrobial therapy., (© 2019 The American College of Veterinary Surgeons.)

Background: Owner questionnaires may be used to assess osteoarthritis (OA) in dogs. The validated American College of Veterinary Surgeons' (ACVS) Canine Orthopaedic Index Questionnaire quantifies quality of life in dogs with orthopaedic disease. This index was modified and translated into Swedish and evaluated for validity, reliability and sensitivity. One group with confirmed moderate elbow dysplasia (n = 117) and one healthy control group (n = 146) without radiographic elbow disease and without lameness were included. Telephone interviews with the dog owners were conducted throughout the study using owner-completed questionnaires., Results: A 16-item questionnaire developed from an initial data set including 22 items, were able to differentiate between the affected group and the control group with good readability. Validity was measured through factor analysis which yielded a three-factor model accounting for 66.3% of the variance. Cronbach's α was 0.89 for the total instrument, > 0.7 for stiffness, lameness and function, but < 0.7 for quality of life. Based on the process the modified questionnaire can be used in Swedish, as the ACVS COI, to make intra-patient comparisons and evaluation of disease progression., Conclusions: A sound owner-completed questionnaire translated into Swedish and modified, able to differ healthy dogs from dogs suffering from chronic osteoarthritis is presented. Performed statistical analysis show the items of the instrument to be reasonable and have high construct validity. The questionnaire may be used in the clinical setting and for research.

Hypertrophic osteopathy, a syndrome characterized by painful distal limb swelling and proliferative periosteal reaction, primarily involves the metacarpal and metatarsal bones and phalanges. Lesions are often bilaterally symmetric and typically affect all four limbs. Hypertrophic osteopathy is frequently associated with primary intrathoracic disease, though this condition has also been reported secondary to intra-abdominal and intrapelvic disease and associated with pregnancy in both people and horses. Over a 20-yr period, five adult female Sichuan takin ( Budorcas taxicolor tibetana ), with 13 total pregnancies, were evaluated because of lameness and distal limb swelling. These clinical signs were observed between 2 and 32 days (mean = 19 days) prior to parturition (gestation period in takin approximately 200-240 days) and resolved in all animals following parturition. Lameness and limb swelling resolved between 8 and 168 days (median = 15 days) after parturition. Sixteen radiographic examinations, from four of the individuals, documented proliferative periosteal reaction, primarily of the metacarpal bones, metatarsal bones, and phalanges. The clinical progression, resolution of signs, and radiographic features in these cases are consistent with hypertrophic osteopathy, secondary to pregnancy. This is the first report describing presumptive hypertrophic osteopathy in takin., (Copyright 2019 by American Association of Zoo Veterinarians.)

Perturbations of ganglioside homeostasis have been observed following stroke whereby toxic simple gangliosides GM2 and GM3 accumulate, while protective complex species GM1 and GD1 are reduced. Thus, there is a need for therapeutic interventions which can prevent ganglioside dysregulation after stroke. A pharmacological intervention using chloroquine was selected for its transient lysosomotropic properties which disrupt the activity of catabolic ganglioside enzymes. Chloroquine was administered both in vitro (0.1 μM), to primary cortical neurons exposed to GM3 toxicity, and in vivo (45 mg/kg i.p.), to 3-month-old male Wistar rats that underwent a severe stroke injury. Chloroquine was administered for seven consecutive days beginning 3 days prior to the stroke injury. Gangliosides were examined using MALDI imaging mass spectrometry at 3 and 21 days after the injury, and motor deficits were examined using the ladder task. Chloroquine treatment prevented ganglioside dysregulation 3 days post-stroke and partially prevented complex ganglioside depletion 21 days post-stroke. Exogenous GM3 was found to be toxic to primary cortical neurons which was protected by chloroquine treatment. Motor deficits were prevented in the forelimbs of stroke-injured rats with chloroquine treatment and was associated with decreased inflammation, neurodegeneration, and an increase in cell survival at the site of injury. Chloroquine administration prevents ganglioside dysregulation acutely, protects against GM3 toxicity in neurons, and is associated with long-term functional and pathological improvements after stroke in the rat. Therefore, targeting lipid dysregulation using lysosomotropic agents such as chloroquine may represent a novel therapeutic avenue for stroke injuries.

Limb-sparing surgery is one of the surgical options for dogs with distal radial osteosarcoma (OSA). This case report highlights the novel application of a three-dimensional (3D)-printed patient-specific polycaprolactone/β-tricalcium phosphate (PCL/β-TCP) scaffold in limb-sparing surgery in a dog with distal radial OSA. The outcomes evaluated included postoperative gait analysis, complications, local recurrence of tumor, metastasis, and survival time. Post-operative gait evaluation showed significant improvement in limb function, including increased weight distribution and decreased asymmetry. The implant remained well in place and increased bone opacity was observed between the host bone and the scaffold. There was no complication due to scaffold or surgery. Significant improvement in limb function and quality of life was noted postoperatively. Local recurrence and pulmonary metastasis were identified at 8 weeks postoperatively. The survival time from diagnosis of OSA to death was 190 days. The PCL/β-TCP scaffold may be an effective alternative to cortical allograft in limb-sparing surgery for bone tumors.

Elbow incongruity plays an important role in the development of elbow dysplasia and its diagnosis can be challenging. The objectives of this systematic review were to discuss elbow biomechanics and recent advances in the assessment of incongruity, to revise the diagnostic protocols suggested, debate advantages and disadvantages of measurements proposed to characterize the joint and improve screening.In spite of advances in the understanding of elbow incongruity, the exact mechanisms involved are not fully elucidated. The elbow is a complex joint and structures in contact differ in different phases of the gait cycle. Advances in the biomechanical field allowed new discoveries and a physiological type of incongruity was described. The next challenge is to unravel the dynamic incongruity. Radiology and computed tomography (CT) are nowadays the imaging tools more applied in clinical practice to quantify incongruity. But a CT standardized screening protocol is required. Most reported findings of incongruity were increased articular joint spaces. The proximity of joint structures and standardization of elbow positioning are identified as the main obstacles to a good interpretation. This review serves to highlight controversy between physiological types of cartilage covering described and pathological changes reported in arthroscopic studies. Radioulnar incongruity was reported more often than humeroulnar incongruity, yet prevalence studies are lacking. Sensitive and reproducible methodologies are in development, which seem primordial to assess the phenotypic heterogeneity., Competing Interests: None declared., (Georg Thieme Verlag KG Stuttgart · New York.)

OBJECTIVE To compare bony changes of the third metacarpal bone (MC3) of Thoroughbred racehorse cadavers with (cases) or without (controls) catastrophic condylar fracture by use of standing MRI. SAMPLE 140 forelimbs from 26 case horses (both forelimbs) and 88 control horses (single forelimb). PROCEDURES Bone marrow lesions (BMLs), identified as a decrease in T1-weighted (T1W) signal and increases in T2*-weighted (T2*W) and short tau inversion recovery (STIR) signals, and dense bone volume percentage (DBVP), identified as decreases in T1W, T2*W, and STIR signals, in the distopalmar aspect of MC3 were recorded. Logistic regression was used to compare fractured and nonfractured limbs of cases and fractured limbs of cases with randomly selected limbs of controls. RESULTS Among cases, fractured limbs were significantly more likely to have BMLs (26/26 [100%]) than were nonfractured limbs (7/26 [27%]). Fractured limbs of cases were significantly more likely to have BMLs (26/26 [100%]) than were limbs of controls (6/88 [7%]). Among cases, there was no significant difference in DBVP between fractured and nonfractured limbs in lateral (26% vs 21%, respectively) or medial (25% vs 20%, respectively) condyles. However, DBVP was significantly greater in fractured limbs of cases than in limbs of controls for lateral (26% vs 16%, respectively) and medial (25% vs 18%, respectively) condyles. CONCLUSIONS AND CLINICAL RELEVANCE Standing MRI revealed a significantly greater degree of bone change in racehorses with condylar fracture when comparing fractured and nonfractured limbs of case horses and fractured limbs of case horses with randomly selected limbs of control horses.

OBJECTIVE To report history, findings from clinical examinations and diagnostic imaging, treatment, and outcomes associated with distal interphalangeal primary degenerative joint disease (DIP-PDJD) and to evaluate diagnostic usefulness and limitations of standing low-field MRI, relative to radiography and ultrasonography, for the diagnosis of DIP-PDJD in horses. DESIGN Retrospective case series with nested evaluation study. ANIMALS 12 client-owned horses. PROCEDURES Medical records were reviewed, and data were collected regarding signalment, history, results of physical and diagnostic imaging examinations, treatments, and outcomes of horses that underwent radiography, ultrasonography, and standing MRI for DIP-PDJD. Findings from radiography, ultrasonography, and MRI were recorded, and abnormal findings were graded. The diagnostic usefulness of MRI, relative to radiography and ultrasonography, in the diagnosis of DIP-PDJD in horses was evaluated. RESULTS A diagnosis of DIP-PDJD was established in 12 of 176 (6.8%) horses that underwent MRI examination of a foot for locomotor disorders. Radiography and ultrasonography enabled confirmation of DIP-PDJD in 3 of the 12 horses, and standing MRI enabled confirmation of DIP-PDJD in the remaining 9. Mean grade for thinning joint space and cartilage were significantly greater when determined with MRI, compared with radiography. Mean grade for osteophytes and periarticular bone remodeling were significantly greater when determined with radiography and ultrasonography, compared with MRI. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that DIP-PDJD can be challenging to detect with routine imaging, especially when synovial effusion and periarticular new bone formation are absent. Standing low-field MRI represents a potentially useful diagnostic tool to diagnose advanced DIP-PDJD in horses.

Digital cryotherapy (DC) is frequently used as laminitis prophylaxis for horses. While DC with ice-water slurries is reported to be safe for up to 48 h, the safety of sleeve-style digital cryotherapy (SSDC) with ice in direct contact with the distal limb has not been evaluated. Our objective was to determine the incidence of distal limb pathologic conditions (DLPC) among horses treated with SSDC. A retrospective study of cases from 2011 to 2015 identified 285 horses treated with SSDC for a minimum of 12 h. Data collected from medical records included demographic, treatment, diagnostic, and SSDC treatment parameters. Bivariate statistics and a generalized linear regression model were created to evaluate risk factors associated with increased incidence of DLPC. Among horses treated with SSDC, 7% had tissue injury of the distal limb. Increasing duration of SSDC was associated with increased incidence of DLPC. Lesions observed included dermatitis, cellulitis, alopecia, coronitis, tissue necrosis, and distal limb edema. These lesions were similar to frostbite, non-freezing cold injury, and prolonged water immersion injuries seen in other species. While the incidence of DLPC was low, the authors recommend that horses undergoing SSDC with ice in direct contact with the skin should be monitored closely for injury when prolonged cryotherapy is clinically indicated. Further studies to improve safety, efficacy, and convenience of alternative methods of DC for horses are warranted., (Copyright © 2018. Published by Elsevier Ltd.)

Medial coronoid process disease is a common leading cause of thoracic limb lameness in dogs. Computed tomography and arthroscopy are superior to radiography to diagnose medial coronoid process disease, however, radiography remains the most available diagnostic imaging modality in veterinary practice. Objectives of this retrospective observational study were to describe the prevalence of medial coronoid process disease in lame large breed dogs and apply a novel method for quantifying the radiographic changes associated with medial coronoid process and subtrochlear-ulnar region in Labrador and Golden Retrievers with confirmed medial coronoid process disease. Purebred Labrador and Golden Retrievers (n = 143, 206 elbows) without and with confirmed medial coronoid process disease were included. The prevalence of medial coronoid process disease in lame large breed dogs was calculated. Mediolateral and craniocaudal radiographs of elbows were analyzed to assess the medial coronoid process length and morphology, and subtrochlear-ulnar width. Mean grayscale value was calculated for radial and subtrochlear-ulnar zones. The prevalence of medial coronoid process disease was 20.8%. Labrador and Golden Retrievers were the most affected purebred dogs (29.6%). Elbows with confirmed medial coronoid process disease had short (P < 0.0001) and deformed (∼95%) medial coronoid process, with associated medial coronoid process osteophytosis (7.5%). Subtrochlear-ulnar sclerosis was evidenced in ∼96% of diseased elbows, with a significant increase (P < 0.0001) in subtrochlear-ulnar width and standardized grayscale value. Radial grayscale value did not differ between groups. Periarticular osteophytosis was identified in 51.4% of elbows with medial coronoid process disease. Medial coronoid process length and morphology, and subtrochlear-ulnar width and standardized grayscale value varied significantly in dogs with confirmed medial coronoid process disease compared to controls. Findings indicated that medial coronoid process disease has a high prevalence in lame large breed dogs and that quantitative radiographic assessments can contribute to the diagnosis., (© 2018 American College of Veterinary Radiology.)

Radiographic flexor cortical lysis indicates advanced degenerative change and its earlier recognition may improve case outcome. Aims of this prospective, diagnostic accuracy study were to determine effects of radiographic beam angle and observer on accuracy of lesion detection. The sample included 36 limbs from 31 horses. Palmaroproximal-palmarodistal oblique (skyline) radiographs were acquired at standard (n = 38) and more shallow (alternate) angles (n = 58). Images were independently reviewed by four experience levels of five observers each (n = 20) for the presence and severity of flexor cortical lysis. Observers also reported their confidence in these answers. Responses were compared based on seeing a standard skyline or multiple projections. The definitive presence (or absence) and severity of lysis was based upon radiologist consensus agreement. When assessed by observer, the identification of lysis and the assessment of its severity was most similar to that of radiologists when observers of all levels of experience were able to view multiple skyline projections (P = 0.399, P = 0.174). Using multiple views to detect lysis resulted in improved sensitivity (85.3% vs. 97.2%, P < 0.001), decreased specificity (82.8% vs. 74.5%, P = 0.03), and improved interobserver agreement (86.0% vs. 90.2%, P = 0.21). On average, observers of all levels of experience became more confident viewing multiple projections (P < 0.001). Skyline radiographs using a flatter angle of incidence improve radiographic detection and characterization of flexor cortical lysis severity, may allow the beam to be tangential to the more distal portion of the navicular bone, and are recommended when flexor cortical lysis is suspected., (© 2018 American College of Veterinary Radiology.)