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Summary: Palmar digital neurectomy (PDN) is used in horses for treating chronic foot pain refractory to other treatments and is most often performed using the guillotine technique or the pull‐through technique. This study was performed to compare the outcome of the guillotine technique and the pull‐through technique for PDN. Medical records of horses undergoing PDN (January 2008–February 2017) were reviewed (guillotine technique: n = 25, pull‐through technique: n = 15). Outcome was obtained by telephone questionnaire. There was no significant difference between treatment groups for the return to athletic activity, presence of residual/recurrent lameness, occurrence of post‐operative complications and owner satisfaction. Outcome was similar for both techniques, albeit with highly variable individual responses. Establishing realistic client expectations is very important because only a proportion of horses remain sound following PDN as time progresses. Adequate case selection is warranted with either technique and should involve accurate localisation of pain with diagnostic anaesthesia and definitive diagnostic imaging techniques. [ABSTRACT FROM AUTHOR]

Summary: Background: There is a need to improve therapies for osteoarthritis in horses. Objectives: To assess the efficacy of equine allogeneic chondrogenic‐induced mesenchymal stem cells combined with equine allogeneic plasma as a novel therapy for osteoarthritis in horses. Study design: Randomised, double‐blinded, placebo‐controlled experiment. Methods: In 12 healthy horses, osteoarthritis was induced in the metacarpophalangeal joint using an osteochondral fragment‐groove model. Five weeks after surgery, horses were randomly assigned to either an intra‐articular injection with chondrogenic‐induced mesenchymal stem cells + equine allogeneic plasma (= intervention) or with 0.9% saline solution (= control). From surgery until the study end, horses underwent a weekly joint and lameness assessment. Synovial fluid was collected for cytology and biomarker analysis before surgery and at Weeks 5, 5 + 1d, 7, 9 and 11. At Week 11, horses were subjected to euthanasia, and the metacarpophalangeal joints were evaluated macroscopically and histologically. Results: No serious adverse events or suspected adverse drug reactions occurred during the study. A significant improvement in visual and objective lameness was seen with the intervention compared with the control. Synovial fluid displayed a significantly higher viscosity and a significantly lower glycosaminoglycan concentration in the intervention group. Other biomarkers or cytology parameters were not significantly different between the treatment groups. Significantly less wear lines and synovial hyperaemia were present in the intervention group. The amount of cartilage oligomeric matrix protein, collagen type II and glycosaminoglycans were significantly higher in the articular cartilage of the intervention group. Main limitations: This study assessed the short‐term effect of the intervention on a limited number of horses, using an osteoarthritis model. This study also included multiple statistical tests, increasing the risk of type 1 error. Conclusions: Equine allogeneic chondrogenic‐induced mesenchymal stem cells combined with equine allogeneic plasma may be a promising treatment for osteoarthritis in horses. The Summary is available in Spanish – see Supporting Information [ABSTRACT FROM AUTHOR]

Background Nutraceuticals are often used in the management of equine osteoarthritis, but scientific evidence of their efficacy is lacking. Objectives To study the preventive effects of two new nutraceuticals after the experimental induction of synovitis in comparison with positive and negative control treatments. Study design Blinded, controlled, randomised experiment. Methods Twenty-four healthy Standardbred horses were randomly allocated to supplement AT (multi-ingredient, 28 days), supplement HP (collagen hydrolysate, 60 days), meloxicam (4 days) or placebo (60 days). Synovitis was induced in the right intercarpal joint by intra-articular injection of 0.5 ng lipopolysaccharide ( LPS) of Escherichia coli while treatments were continued. Blood and synovial fluid were sampled before treatment, immediately prior to LPS injection, and at 8, 24 and 48 h post-injection. Synovial fluid samples were analysed for total nucleated cell count ( TNCC), total protein ( TP) and selected biomarkers (prostaglandin E2 [ PGE2], interleukin-6 [ IL-6], glycosaminoglycans [ GAGs], type II collagen synthesis [ CPII], matrix metalloproteinase [ MMP]). Lameness was scored by visual examination and pressure plate analysis immediately prior to LPS injection, and at 8, 24 and 48 h post-injection. Clinical examinations were performed before treatment, immediately prior to LPS injection, at 2, 4 and 6 h post-injection, and then twice per day during the test period. Results Before treatment and intra-articular challenge, there were no statistically significant differences among the treatment groups for any of the parameters. After intra-articular challenge, the placebo group showed significantly higher synovial fluid TP, TNCC and PGE2 compared with the meloxicam group, although the model did not induce a relevant amount of lameness. Both nutraceuticals resulted in significantly lower synovial fluid TP, TNCC and PGE2 compared with placebo. No statistical differences in IL-6, GAGs, CPII or MMPs were observed among treatment groups. No adverse effects were observed. Main limitations Despite evidence of synovitis, lameness was too mild to detect. Conclusions The preventive administration of these nutraceuticals showed anti-inflammatory effects in this validated synovitis model. Therefore, further studies of their clinical applicability are warranted. [ABSTRACT FROM AUTHOR]

During endoscopy (tenoscopy) of the distal aspect of the equine digital flexor tendon sheath (DFTS), the digital manica flexoria can be visualized connecting the distal branches of the superficial digital flexor tendon. However, this structure has been inconsistently described and variably named in the veterinary literature. The objectives of this study were to describe the presence, configuration and variability of the digital manica flexoria in the equine distal limb. Dissection of 144 equine cadaveric limbs revealed the presence of this structure in all the feet, although different types and conformations were identified. In the forelimbs, a membranous digital manica flexoria predominated (94%; P < 0.001), in particular a synovial bridge type (83%; P < 0.001). In the hindlimbs, a tendinous digital manica flexoria predominated (93%; P < 0.001), in particular the oblique-crossing of tendinous bundles (61%; P < 0.001). Passage dorsal to the digital manica flexoria towards the distal DFTS was only possible in 22 of the 144 limbs, all forelimbs. Clinicians should be aware of the intra- and inter-individual anatomical variations of the digital manica flexoria to avoid misinterpretation during ultrasonographic and tenoscopic examinations of the DFTS. [ABSTRACT FROM AUTHOR]

Reasons for performing study The effects of handler position and perineural anaesthesia in sound horses need investigation to facilitate interpretation of pressure plate analysis in lame horses. Objectives To evaluate the effect of handler position and perineural anaesthesia on limb loading and particularly hoof balance in sound horses. Study design Nonrandomised crossover study. Methods Six sound horses were walked and trotted over a pressure plate, with the handler on the left and subsequently on the right side, and finally after a bilateral low palmar digital nerve block. One week later this procedure was repeated before and after a bilateral abaxial sesamoidean nerve block. Peak vertical force, vertical impulse and stance time of 5 hoof prints of both forelimbs were obtained (126 Hz), and toe-heel and mediolateral hoof balance curves of the vertical force were plotted throughout stance. Limb-loading and timing data and hoof balance data (beginning, middle and end of the stance phase) were statistically compared (handler left compared with right; before compared with after low palmar digital nerve block and abaxial sesamoidean nerve block; baseline at first measurement session compared with second). Results There were no significant effects of handler position and perineural anaesthesia on peak vertical force, vertical impulse and stance time. Hoof balance curves were not affected by handler position or perineural anaesthesia. The limb loading data and hoof balance curves were comparable for each horse over the one-week interval. Conclusions Handler position and perineural anaesthesia do not have an effect on limb loading and toe-heel and mediolateral hoof balance in sound horses, which is of fundamental importance before embarking on pressure plate analysis for lameness diagnosis. [ABSTRACT FROM AUTHOR]

Reasons for performing study: Controversy exists about the specificity of diagnostic analgesia of the digital flexor tendon sheath (DFTS) in horses. Objectives: To evaluate the degree of diffusion of mepivacaine from the equine DFTS to adjacent synovial structures. Study design: Crossover experiment. Methods: Under general anaesthesia, the DFTS of one front and one hindlimb of 8 horses were injected simultaneously with mepivacaine. Synovial fluid samples of the injected DFTS, the adjacent metacarpo-/metatarsophalangeal (MCP/MTP) joint, proximal interphalangeal joint, distal interphalangeal joint, navicular bursa and contralateral MCP/MTP joint were collected 15 min post injection (T15) from one of the injected limbs and 60 min post injection (T60) from the other limb. Venous blood samples were obtained at T0, T15 and T60 to evaluate systemic distribution of mepivacaine. After a 2-week washout period, the procedure was repeated using the same limbs but reversing the time of sampling (front vs. hindlimbs). The concentration of mepivacaine in samples was measured with a commercial ELISA kit. Results: Mepivacaine concentrations in the DFTS samples, at both T15 (5077 mg/l) and T60 (3503 mg/l), exceeded those estimated sufficient to produce synovial analgesia (100 mg/l or 300 mg/l). Mepivacaine was found in all synovial structures adjacent to the injected DFTS and in the contralateral MCP/MTP joints, but concentrations were low, with a maximum value of only 3.2 mg/l. With the exception of the navicular bursa samples, the mepivacaine concentrations in the adjacent synovial structures were significantly higher at T60 than at T15 (P<0.03). Significantly higher mepivacaine concentrations were found in the ipsilateral than the contralateral MCP/MTP joints at T60 (P<0.001). Blood samples had significantly higher mepivacaine concentrations at T15 and T60 than at T0 (P<0.001). Conclusions: Mepivacaine injected into the DFTS of horses diffuses towards adjacent synovial structures without achieving clinically relevant concentrations. [ABSTRACT FROM AUTHOR]

Reasons for performing study Thus far, pressure-plate analysis has been limited to measurements on a hard surface, whereas equine athletes routinely perform on a deformable substrate. Objectives To explore pressure-plate analysis on arena footing. Study design Nonrandomised crossover study using noninvasive techniques. Methods Five sound, unshod ponies were walked and trotted over a pressure plate in 2 different conditions. In the first session, the plate was covered with only a 5 mm rubber mat, and in the second session, with an additional 50 mm layer of sand and synthetic fibres. Limb loading and timing variables (peak vertical force, vertical impulse, peak vertical pressure, hoof contact area and stance phase duration) were obtained. Toe-heel and mediolateral hoof balance of the vertical force were calculated throughout stance (126 Hz). Results Peak vertical force, vertical impulse, peak vertical pressure and stance phase duration were decreased on the soft substrate, while hoof contact area increased. At impact, there was more even load distribution between the toe and heel region on the soft vs. hard surface. At mid-stance, there was more loading of the toe region on the soft compared with the hard surface. At impact, there was more even load distribution between lateral and medial on the soft vs. hard surface at walk, but not at trot. Conclusions Comparison of observed vs. expected impulse indicated that the main factor involved in the lower loading on the soft surface is the dampening effect of the soft substrate, although definitive conclusions require concurrent force-plate analysis. The pressure plate permitted quantitative evaluation of hoof balance of the vertical force on a deformable surface at the walk and trot and proved that there is more even load distribution on arena footing. [ABSTRACT FROM AUTHOR]

Reasons for performing study Controversy exists about the desensitisation obtained after diagnostic analgesia of the digital flexor tendon sheath ( DFTS) during lameness examinations. Objectives To determine whether DFTS analgesia results in inadvertent desensitisation of the palmar/plantar digital nerves and whether this depends on the injection technique used. Study design Crossover experimental study. Methods The DFTS of 9 horses were injected with local anaesthetic solution and radiodense contrast medium using one of the following techniques: Proximal (at lateral proximal recess of the DFTS), Axial (axial to the lateral proximal sesamoid bone), Base (at base of the lateral proximal sesamoid bone), and Distal (at palmar/plantar mid-pastern). In total, 72 injections were performed. Skin desensitisation at the heel bulbs was tested with a dynamometer before and at 15, 30, 90 and 120 min after injection. Results Overall, complete desensitisation of a heel bulb at one or more time points after injection occurred in 22 limbs (30.6%). An additional 7 limbs were partially desensitised. Complete skin desensitisation occurred in 10, 3, 4 and 5 limbs using the Proximal, Axial, Base and Distal techniques respectively. Significant differences between techniques were only found at T30. The probability of skin desensitisation at the heel bulbs was 4 times higher when using the Proximal compared with the Axial and Base techniques in the forelimbs, and 3 times higher compared with the Axial and Distal techniques in the hindlimbs. Skin desensitisation nearly always occurred exclusively on the lateral heel bulb. Bilateral desensitisation only occurred in 5 limbs. Conclusions Anaesthesia of the palmar/plantar digital nerves with distal limb desensitisation often occurs after DFTS analgesia. A higher chance of desensitisation exists when injecting the proximal DFTS recess. It is advisable to verify skin sensitivity at the heel bulbs after DFTS analgesia to avoid false interpretations about the origin of pain causing lameness. [ABSTRACT FROM AUTHOR]

Reasons for performing study Lysis of the axial aspect of equine proximal sesamoid bones ( PSBs) is a rare condition reported to have septic or traumatic origins. Limited information exists regarding imaging of nonseptic axial osteitis of a PSB. Objectives To report the clinical, radiographic, ultrasonographic, computed tomographic and intra-arterial contrast-enhanced computed tomographic abnormalities in horses with axial nonseptic osteitis of a PSB. Study design Retrospective clinical study. Methods Eighteen horses diagnosed with nonseptic osteitis of the axial border of a PSB between 2007 and 2012 were reviewed retrospectively. Case details, clinical examination, radiographic, ultrasonographic, computed tomographic and intra-arterial/intra-articular contrast-enhanced computed tomographic features were recorded, when available. Radiographic, ultrasonographic and computed tomographic evaluations of the fetlock region had been performed on 18, 15 and 9 horses, respectively. The effect of the degree of lysis on the grade and duration of lameness was determined. Results All horses had chronic unilateral lameness, 4 with forelimb and 14 with hindlimb signs. On radiographs, lysis was identified in both PSBs in 14 horses, one PSB in 3 horses and in one horse no lysis was identified. The degree of osteolysis was variable. Ultrasonography identified variably sized irregularities of the bone surface and alteration in echogenicity of the palmar/plantar ligament ( PL). All horses undergoing computed tomographic examination (n = 9) had biaxial lysis. The lesions were significantly longer and deeper on computed tomographic images compared with radiographic images. Intra-arterial contrast-enhanced computed tomography may reveal moderate to marked contrast enhancement of the PL. There was no significant effect of the degree of lysis on the grade and duration of lameness. Conclusions Lesions of nonseptic axial osteitis of a PSB can be identified using a combination of radiography and ultrasonography. Computed tomography provides additional information regarding the extent of the pathology. [ABSTRACT FROM AUTHOR]

Reasons for performing the study Few reports are available on the relationship between developmental orthopaedic diseases ( DOD) and future performances in Warmblood horses. Objectives To investigate the relationship between performance and the presence of DOD lesions. Methods Records of Warmblood stallions for which radiographic and performance data were available were collected. Showjumping performances were expressed as scores derived from the final ranking of horses in each competition. These scores are available in an established performance database. The relationship between radiographic findings and both performance scores and number of performances was analysed using a linear regression model. Results Two hundred and fifteen horses met the inclusion criteria. There was no difference in either the number of performances or performance score between horses categorised as affected with DOD lesions (independent of joint location) compared with controls. Significantly lower numbers of performances were recorded for horses with osteochondral fragments ( OCD) located at the dorsal aspect of the sagittal ridge of the metacarpo/metatarsophalangeal bone. No significant difference was found between horses affected with DOD lesions of the tarsocrural joint and controls. Horses with osteochondrosis of the lateral trochlear ridge of the femur had both significantly lower performance scores and numbers of performances compared with controls. Conclusion This study demonstrated that specific DOD location and site within the joint have an influence on performance. Osteochondral fragments in the femoropatellar and at the dorsal aspect of the sagittal ridge of the metacarpo/metatarsophalangeal joint resulted in lowered performance. Fragmentation in the tarsocrural joint had no influence on performance. Potential relevance The future athletic performance of Warmblood jumping horses may be limited as a result of OCD in the femoropatellar joint and to a certain extent the metacarpo/metatarsophalangeal joint. [ABSTRACT FROM AUTHOR]

Reasons for performing study Equine joint infection is a life-threatening disorder, and confirmation of the diagnosis can be difficult. Synovial fluid biomarkers may assist the discrimination between infectious and noninfectious joint disease. Objectives This study investigates whether the immunological detection of total and enzymatically active myeloperoxidase ( MPO) assists the diagnosis of joint infection in horses. Methods The following 4 sample groups were included: healthy; osteochondritis dissecans ( OCD); traumatic synovitis; and culture-confirmed infected joints. Synovial fluid was analysed for total MPO by a horse-specific sandwich enzyme-linked immunosorbent assay ( ELISA) and for active MPO using the specific immunological extraction followed by enzymatic detection ( SIEFED) technique. Western blot analysis was performed to confirm the antibody specificity. Results Synovial fluid from infected joints contained significantly more total and active MPO than samples from healthy joints, joints affected by OCD and joints with traumatic synovitis. Cut-off values were set at 5000 and 350 ng/ml for total and active MPO, respectively, with fair sensitivity, specificity, positive and negative predictive values and likelihood ratios for infection. Correlation coefficients were reported between the total as well as the active MPO levels and the routine synovial fluid parameters, i.e. the white blood cell count, the neutrophil count and the total protein level. No correlation was observed between MPO and either the age of the horse or the joint affected. Western blotting confirmed the antibody specificity for equine MPO. Conclusions and potential relevance Synovial fluid MPO was identified as a very promising biomarker to augment the discrimination of infectious vs. noninfectious joint disease in horses. Both ELISA and SIEFED techniques can be used for its specific and rapid detection. The analysis of synovial fluid MPO can be used as a complementary test to aid in the discrimination between infectious and noninfectious joint disease, especially when the white blood cell counts and the total protein level are inconclusive. [ABSTRACT FROM AUTHOR]

Summary The medical records of 30 horses (18 Warmbloods, 7 draught horses, 3 other breeds and 2 of unknown origin) with chronic proliferative pododermatitis (canker) were reviewed and long-term outcome was obtained by telephone questionnaire. In 28/30 cases, the owner was the first to discover the problem. The disease was initially recognised as canker in only 5/28 cases, whereas in 10/28 cases a treatment for thrush had been continued for several months before referral. There was a similar prevalence in the fore (41) and hind (44) hooves; 13/30 horses had 4 hooves affected. Treatment consisted of surgical debridement and hoof care. Duration of hospitalisation was significantly decreased in horses receiving oral prednisolone for 3 weeks compared to those without this additional systemic treatment (mean ± s.d. 24 ± 5 days, n = 7 vs. 40 ± 19 days, n = 19, respectively). Long-term follow-up ranged from 3 months to 6 years (36 ± 22 months) and was available for 24 horses. No recurrence was reported in 10 horses. In 14 horses problems recurred within the first year, and 6 had been subjected to euthanasia for this reason specifically, whereas the others were managed by regular trimming. There was no significant association between recurrence and the number of affected hooves or the use of any systemic treatment. Horses with delayed referral because of preceding treatments had significantly more chance to develop recurrence, highlighting the need for prompt diagnosis and subsequent treatment. [ABSTRACT FROM AUTHOR]

Summary Reasons for performing study: Standard methods for culturing equine synovial fluid (SF) are often unrewarding. Evidence-based information on the relative efficiency of different systems used for optimisation of isolation of microorganisms from equine SF is lacking. Objectives: To compare the results of different culture systems performed in parallel on SF samples from horses clinically diagnosed with synovial sepsis. Methods: Synovial fluid specimens were collected between February 2007 and October 2008 from all horses admitted to a referral hospital that were clinically diagnosed with synovial sepsis and from control horses. Synovial fluid samples were cultured in parallel by: 1) direct agar culture (DA); agar culture after: 2) lysis-centrifugation pretreatment (LC); 3) conventional enrichment (CE); 4) combined LC/CE; or 5) blood culture medium enrichment using an automated system (BACTEC 9050). Results: Ninety SF samples from 82 horses were included, together with 40 control samples. Seventy-one of 90 samples (79%) were culture-positive by using blood culture medium enrichment (BACTEC), which was significantly higher compared to all other methods. BACTEC enrichment was never negative while any of the other methods was positive. Although agar culture following LC and/or CE resulted in a slightly higher number of positive samples compared to DA, this difference was not significant. All control samples were culture negative by the 5 different techniques. Although the majority of samples containing isolates recovered without enrichment, culture results after BACTEC enrichment were available on the same day as for agar culture with or without LC (19/23 samples), while CE postponed recovery by at least one day in 20/23 samples. Conclusion: Blood culture medium enrichment is superior to other techniques for isolation of bacteria from SF of horses. The use of an automated system allows enrichment without substantially postponing recovery of microorganisms. Potential relevance: The efficient and fast isolation of microorganisms from infected SF by the BACTEC system allows for rapid susceptibility testing and a more appropriate antibiotic treatment. [ABSTRACT FROM AUTHOR]

The in vivo behaviour of 5% gentamicin sulphate ocular mini-tablets (2-mm diameter, 6.525 mg weight) was compared with gentamicin eye drops in six ponies. Two mini-tablets were inserted on the bulbar conjunctiva of the right eye while a similar dose of gentamicin was administered via eye drops in the left eye. Irritation induced by the mini-tablets and the eye drops was evaluated using a visual analogue scale (0–10). Tears were sampled with ophthalmologic absorption triangles for 1 min for the determination of the concentration of gentamicin sulphate using a microbiological plate diffusion method. Irritation induced by the tablets was minor and clinically acceptable (overall median score of 1.7 ± 1.4). Eye drops induced a sharp increase in gentamicin sulphate concentration (364.4 μg/mL after 5 min) followed by a fast decline (10.8 μg/mL after 60 min). The increase in concentration induced by the ocular mini-tablets was less pronounced (up to 56.2 μg/mL after 30 min) and followed by a gradual decrease; the concentration remained above 15 μg/mL for 8 h. Ocular 5% gentamicin sulphate mini-tablets are clinically well-tolerated in ponies, assuring a constant concentration in the tears for at least 8 h. [ABSTRACT FROM AUTHOR]