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Simple Summary: Wound care is a challenging part of equine veterinary practice and there are a variety of wound dressings and strategies to manage wounds. Our goal was to ascertain the relative efficacy of honey when compared to common wound dressings as it pertains to reducing bacterial growth. This experiment was performed in a laboratory setting where different species of bacteria were grown in a simulated wound environment. These bacteria were then exposed to medical-grade Manuka honey, local honey, and commercial, food-grade honey as well as other commonly used wound dressings to see how effective each wound dressing was on reducing bacterial growth. Our results showed that polyhexamethylene biguanide (PHMB, a commonly used wound dressing) was best at reducing bacterial growth. Local honey out-performed Manuka and store-bought honeys. Interestingly, the most susceptible type of bacteria was harvested from an actual equine wound when compared to the lab-grown bacteria. We suspect that the complex wound environment plays a large role in determining the efficacy of wound dressings. Our results provide data to practitioners so they can decide how to best manage an infected wound based on the type of bacteria growing. Antimicrobial resistance is becoming a problem of concern in the veterinary field, necessitating the use of effective topical treatments to aid the healing of wounds. Honey has been used for thousands of years for its medicinal properties, but in recent years medical-grade Manuka honey has been used to treat infected wounds. The goal of this study was to determine the relative susceptibility of four common equine wound pathogens to ten different types of antimicrobial agents based on the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The pathogens studied include ATCC lab-acclimated Pseudomonas aeruginosa, Escherichia coli, and methicillin-resistant Staphylococcus aureus and one from an equine sample submitted to the Colorado State Veterinary Diagnostic Laboratory (Streptococcus equi ssp. zooepidemicus (Streptococcus zooepidemicus)). An additional goal of the study was to describe the comparison of bactericidal activity of medical-grade Manuka honey, local honey, and commercial, food-grade honey to other commonly used wound dressings (20% hypertonic saline, silver sulfadiazine cream, PHMB gauze, and PHMB foam). The objective is to provide veterinary practitioners with comparative data on the use of a variety of antimicrobial dressings for inhibiting the growth of common wound bacteria. MIC and MBC for Manuka, store, and local honeys were comparable to those of sterile gauze, sugar, and hypertonic saline. Across bacterial species, local honey proved to have more bactericidal activity when compared to Manuka honey and commercial, food-grade honey. The MIC and MBC for PHMB gauze and foam was consistently at a higher dilution compared to the other antimicrobials. The majority of antimicrobials exhibited stronger inhibitory and bactericidal activity against a Streptococcus zooepidemicus isolate obtained from a wound compared to other bacteria that were ATCC lab-acclimated. Additional research for in vivo applications needs to be done to see whether differences exist in effective wound management. [ABSTRACT FROM AUTHOR]

Polar bears (Ursus maritimus) face a number of challenges that threaten the survival of the species. Captive breeding represents one essential facet of species conservation, but aspects of the polar bear's reproductive physiology, such as follicle maturation, coitus-induced ovulation, and pseudopregnancy, are poorly characterized and present challenges for enhancing natural reproductive success and the application of advanced reproductive techniques. Due to the absence of a reliable transrectal or transabdominal ultrasound method for ovarian examination in the species, the ovaries of two adult female polar bears were examined laparoscopically to evaluate the feasibility of surgical access to the ovaries, oviduct, and uterus. The minimally invasive procedure was easily and rapidly performed in both bears and all procedures. Direct visual assessment of the ovary was possible after dissection of a fatty bursal sac, which completely enclosed the ovaries. In the second bear, laparoscopic manipulation of the ovary to draw it closer to the body wall enabled transcutaneous ultrasound. Laparoscopy may be a valuable tool to aid in the application of advanced reproductive technologies in polar bears. [ABSTRACT FROM AUTHOR]

Minimally invasive surgery in the human was first identified in mid 900's. The procedure as is more commonly practiced now was first reported in 1912. There have beenmany advances and new techniques developed in the past 100 years. Equine laparoscopy, was first reported in the 1970's, and similarly has undergonemuch transformation in the last 40 years. It is now considered the standard of care in many surgical techniques such as cryptorchidectomy, ovariectomy, nephrosplenic space ablation, standing abdominal exploratory, and many other reproductive surgeries. This manuscript describes the history of minimally invasive surgery, and highlights many of the techniques that are currently performed in equine surgery. Special attention is given to instrumentation, ligating techniques, and the surgical principles of equine minimally invasive surgery. [ABSTRACT FROM AUTHOR]

To appraise conservation status of the Yaqui catfish Ictalurus pricei, we reviewed literature and unpublished records on a captive stock, examined voucher specimens at museums, re-sampled historical localities in the Yaqui, Mayo, and Fuerte river basins, and we surveyed rivers further south. A total of 72 specimens of native Ictalurus was collected in the Yaqui, Fuerte, Sinaloa, Culiacán, and San Lorenzo river basins. No native Ictalurus was collected in the Mayo Basin. Distribution of the Yaqui catfish appears restricted to the Yaqui, Mayo and Fuerte river basins, all of which now harbor nonnative blue (I. furcatus) and channel (I. punctatus) catfishes. The nonnative black bullhead (Ameiurus melas)i s now known from the Yaqui Basin and the flathead catfish (Pylodictis olivaris) has been recorded anecdotally in the Yaqui Basin. Threats to the Yaqui catfish have increased in recent years and hybridization with the channel catfish now appears widespread. We conclude that the Yaqui catfish should be considered endangered throughout its range and that status of native populations of Ictalurus in the United States and Mexico should be reviewed and management intensified. [ABSTRACT FROM AUTHOR]

Objective-To compare pain responses in stallions undergoing standing laparoscopic cryptorchidectomy following intratesticular or mesorchial infiltration of lidocaine. Design—Clinical trial. Animals—20 stallions with 1 or 2 undescended testes. Procedures—Standing horses were administered a nonsteroidal anti-inflammatory drug and a caudal epidural injection of detomidine hydrochloride and underwent laparoscopic cryptorchidectomy. The undescended testis (1/horse) was grasped to determine the preoperative pain response (present vs absent) and assess severity of pain (by use of a visual analog scale [VAS]). The undescended testis or its mesorchium was injected with 2% lidocaine (10 mL; saline (0.9% NaCI) solution (10 mL) was injected in the untreated structure. Presence and severity of pain was determined by 2 individuals as the testis was grasped following infiltration and at the times of ligature placement and transection of the spermatic cord. Serum cortisol concentration was analyzed preoperatively, after ligation, and after transection. Presence or absence of signs of pain, severity of pain, and serum cortisol concentrations were compared within and between treatment groups. Results—Detection of signs of pain and VAS pain scores did not differ between observers at any time point. Perceived pain responses associated with ligature placement differed significantly from preoperative responses. Pain responses and serum cortisol concentrations after intratesticular and mesorchial infiltration of lidocaine did not differ. Conclusions and Clinical Relevance—Results suggested that intratesticular or mesorchial infiltration of lidocaine combined with administration of a nonsteroidal anti-inflammatory drug and caudal epidural injection of detomidine provides adequate analgesia in standing stallions undergoing laparoscopic cryptorchidectomy. [ABSTRACT FROM AUTHOR]

Stromatolites, the dominant Precambrian life form, declined in the Phanerozoic to occur today in only a few sites. This decline has been attributed to evolution of metazoan grazers, but stromatolites in our study site, Cuatro Ciénegas, Coahuila, México, harbor diverse macroinvertebrates. Drawing on food chain theory, we hypothesized that fish predation on invertebrates controls invertebrate populations, allowing stromatolites to flourish in Cuatro Ciénegas. Our experiment used small mesh (1 mm) cages to exclude all but larval fishes, and larger (6.5 mm) cages to exclude all larger fishes (including the molluscivorous and omnivorous endemic polymorphic cichlid, Herichthys minckleyi), but allow access to all sizes of the abundant endemic pupfish, Cyprinodon bifasciatus. No effects of treatments on invertebrate densities were noted at 6 week, but significant effects were observed on specific taxonomic groups after 3 month. In absence of fishes, hydrobiidae snails and ceratopogonids increased 3- and 5-fold, respectively, and invertebrate assemblage composition varied among treatments. Algal biomass was not affected by treatments, but algal species composition appeared to change. Overall results suggest that fish assemblages structure invertebrate assemblages, and that fishes may also be factors in determining algal communities. [ABSTRACT FROM AUTHOR]

Objective—To compare intraoperative pain responses following intraovarian versus mesovarian injection of lidocaine in mares undergoing laparoscopic ovariectomy. Design Randomized controlled trial, Animals—15 mares between 4 and 20 years old. Procedure—Standard bilateral laparoscopic ovariectomy was performed. Prior to manipulation of the ovary, 2% lidocaine (10 mL) was injected into the ovary and saline (0.9% NaCl) solution (10 mL) was injected into the mesovarium on 1 side, with saline solution (10 mL) injected into the ovary and 2% lidocaine (10 mL) injected into the mesovarium on the other side. Presence (yes vs no) and severity (visual analogue scale) of pain were scored at 5 times (grasping of the ovary, dissection of the mesosalpinx, tightening of the first loop ligature, tightening of the second loop ligature, and transection of the ovarian pedicle) by 2 individuals blinded to treatment and each other's observations. Results—During 4 of the 5 observation periods, significantly fewer mares had signs of pain following mesovarian injection of lidocaine, and during 2 of the 5 observation periods, visual analogue scale score was significantly lower. Conclusions and Clinical Relevance—Results suggest that mesovarian injection of lidocaine is associated with significantly lower pain responses, compared with intraovarian injection, in horses undergoing laparoscopic ovariectomy. [ABSTRACT FROM AUTHOR]

Examines the treatment of suppurative facial cellulitis and panniculitis caused by corynebacterium pseudotuberculosis in horses. Observation of large facial wound and multiple small abscesses; Evidence of granulation tissue under the necrotic skin; Performance of skin biopsy.

Simple Summary: When removing the ovaries of a mare via laparoscopic technique, there is potential to drop the ovary in the abdomen when trying to exteriorize it through the abdominal wall. If the ovary can no longer be seen with the laparoscope, then the procedure is converted to a flank incision and the ovary is identified and removed by hand. Having to convert the procedure negates the benefits of the minimal invasive laparoscopic procedure and increases the risk of post-operative complications. The objective of this study was to identify if amputated ovaries left in the abdomen during surgery would atrophy or if they would regain a blood supply and produce hormones. After surgery, the mare's hormone values were at low levels and an improvement in all mare's behavior and general herd dynamics was observed. While this study does not encourage to leave ovaries in the abdomen after amputation, we report no complications related to their voluntary release into the abdomen. There is risk of dropping an amputated ovary within the abdomen during standing laparoscopic ovariectomies in mares. If the ovary can no longer be directly visualized with the laparoscope, the procedure is then converted to a flank laparotomy for manual retrieval of the ovary which negates the minimally invasive nature of the laparoscopic procedure. The objective was to identify if ovaries left in the abdomen after amputation would atrophy or if they re-vascularize. Standing bilateral ovariectomies were performed in mature mares, but after transection of the ovarian pedicle, the ovaries were intentionally dropped and left within the abdomen. Post-operative endocrine values were at basal levels and an improvement in all mare's behavior and general herd dynamics was observed. While this study does not encourage to leave ovaries in the abdomen after amputation, we report no complication related to their voluntary release into the abdomen. [ABSTRACT FROM AUTHOR]

Examines the efficacy of using a high-power ultrasonic shears for laparoscopic ovariectomy in mares. Description of the technique; Efficacy of the surgical technique; Capacity to transect thr ovarian pedicle.

The American eel (Anguilla rostrata) has long been regarded as a panmictic fish and has been confirmed as such in the northern part of its range. In this paper, we tested for the first time whether panmixia extends to the tropical range of the species. To do so, we first assembled a reference genome (975 Mbp, 19 chromosomes) combining long (PacBio and Nanopore and short (Illumina paired‐end) reads technologies to support both this study and future research. To test for population structure, we estimated genotype likelihoods from low‐coverage whole‐genome sequencing of 460 American eels, collected at 21 sampling sites (in seven geographic regions) ranging from Canada to Trinidad and Tobago. We estimated genetic distance between regions, performed ADMIXTURE‐like clustering analysis and multivariate analysis, and found no evidence of population structure, thus confirming that panmixia extends to the tropical range of the species. In addition, two genomic regions with putative inversions were observed, both geographically widespread and present at similar frequencies in all regions. We discuss the implications of lack of genetic population structure for the species. Our results are key for the future genomic research in the American eel and the implementation of conservation measures throughout its geographic range. Additionally, our results can be applied to fisheries management and aquaculture of the species. [ABSTRACT FROM AUTHOR]

Simple Summary: Abdominal surgery is commonly performed in horses to treat gastrointestinal lesions or inflammatory conditions. Potential postoperative complications such as incisional infection have been shown to be reduced with appropriate perioperative antimicrobial administration. However, a recent survey of board-certified specialists on antimicrobial practices in horses undergoing celiotomy demonstrated that usage patterns were highly variable amongst practitioners and, at times, not concordant with the current literature. Furthermore, in light of recent evidence supporting an increase in antimicrobial resistance in equine veterinary practice, periodic reconsideration of antimicrobial regimens for commonly performed procedures is indicated. The goal of this retrospective study was to provide an updated review of the effect of antimicrobial protocols and other perioperative factors on postoperative complications in horses undergoing celiotomy at a referral hospital with the goal of advancing practitioners' understanding of best practices and opportunities to reduce complications. Recognition of antimicrobial resistance in equine practice has increased over the past decade. The objective of this study was to provide an updated retrospective review of antimicrobial regimens in one tertiary referral hospital and to evaluate the association with postoperative complications. A secondary objective was to evaluate other perioperative factors including surgical procedure, anesthetic and recovery parameters, and the effect of perioperative medications on complications and outcomes. A computerized search of medical records was performed to identify horses undergoing exploratory celiotomy from 1 January 2008 to 31 December 2021. A total of 742 celiotomies were performed (608 completed, 134 terminated intraoperatively). Factors recorded were evaluated using logistic regression for the presence of either incisional infection, postoperative ileus, or other complications postoperatively. Antimicrobial type or timing (pre-, intra-, or postoperative) were not associated with decreased risk of incisional infection or postoperative ileus; however, the duration of NSAID use was positively associated with incisional infection (OR 1.14 per day). Lidocaine and alpha-2-agonist administration postoperatively were also associated with increased incidence of postoperative ileus (OR 21.5 and 1.56, respectively). Poor recovery quality (OR 4.69), the addition of other antimicrobials besides penicillin/gentamicin postoperatively (OR 3.63), and an increased number of different NSAID classes used (OR 1.46 per additional) were associated with other complications. Implementation of enterotomy was associated with decreased risk of other complications (OR 0.64). These findings provide an updated summary of factors associated with postoperative complications in horses undergoing celiotomy. [ABSTRACT FROM AUTHOR]

A response by Ellis G. Farstvedt and Dean A. Hendrickson to a letter to the editor about their article "Intraoperative Pain Responses Following Intraovarian Versus Mesovarian Injection of Lidocaine in Mares Undergoing Laparoscopic Ovariectomy" in the December 2005 issue is presented.

Simple Summary: Recommendations for antimicrobial prophylaxis are well described for abdominal surgery in human medicine, but the information is limited for equine veterinary practice. In addition, recent studies support a reduced duration of antimicrobials postoperatively in horses undergoing celiotomy compared to what has been previously reported; however, protocols vary widely between practices. The overall objective of this study was to provide an updated characterization of the 'current state of play' of antimicrobial use in horses undergoing emergency colic surgery and the perceived risk of postoperative complications. Specifically, the aim was to poll veterinary internists and surgeons to determine current usage among respondents in the United States. Improved knowledge of recommendations for antimicrobial prophylaxis for commonly performed procedures in equine practice, such as abdominal surgery, may help to reduce postoperative complications and enhance antimicrobial stewardship at a time when resistance is increasing in equine practice. In the past decade, there has been a considerable increase in the recognition of antimicrobial resistance in equine practice. The objective of this study was to survey the current clinical use of antimicrobials for a commonly performed surgical procedure (exploratory celiotomy) with the goal of understanding how recent literature and changes in microbial resistance patterns may have impacted antimicrobial selection practices. An electronic survey was distributed to veterinary professionals within the American College of Veterinary Internal Medicine (ACVIM) and the American College of Veterinary Surgery (ACVS). A total of 113 completed surveys were returned. Practitioners reported antimicrobials were most frequently given 30–60 min preoperatively (63.1%). Two antimicrobial classes were typically administered (95.5%), with gentamicin (98.2%) and potassium penicillin (74.3%) being the most common. Antimicrobials were typically not re-dosed intraoperatively (78.6%). Factors that affected overall treatment length postoperatively included resection (81.4%), bloodwork (75.2%), enterotomy (74.3%), fever (85.0%), incisional complications (76.1%), and thrombophlebitis (67.3%). The most common duration of antimicrobial use was 1–3 d for non-strangulating lesions (54.4% of cases) and inflammatory conditions such as enteritis or peritonitis (50.4%), and 3–5 d for strangulating lesions (63.7%). Peri-incisional and intra-abdominal antimicrobials were used by 24.8% and 11.5% of respondents, respectively. In summary, antimicrobial usage patterns were highly variable among practitioners and, at times, not concordant with current literature. [ABSTRACT FROM AUTHOR]

Background: The frequency of surgical site infection (SSI) following orthopaedic implant placement in horses has been reported but not compared with respect to specific antibiotic protocols administered. Objectives: To determine factors associated with SSI in horses undergoing proximal interphalangeal joint (PIPJ) arthrodesis including perioperative antibiotic protocols. Methods: Records were evaluated (2010–2019), and horses undergoing PIPJ arthrodesis were identified. Patient signalment, supervising surgeon, reason for surgery, limb, implants placed, anaesthetic time, duration casting/coaptation postoperatively, antibiotic regimen and incidence/onset SSI were recorded. Bayesian and frequentist logistic regressions were used to estimate the contribution of covariates to infection occurrence. Results: Fifty‐four PIPJ arthrodeses were performed. SSI occurred in 2/54 (3.7%) on day 15,30. Arthrodesis was performed most commonly for osteoarthritis (33/54, 61.1%), fracture (11/54, 20.4%), and subluxation (5/54, 9.3%). Perioperative systemic antibiotics were administered 1–3 days (15/54, 27.8%) or > 3 days (39/54, 72.2%). Antibiotic protocols included cefazolin/gentamicin (20/54, 37%), cefazolin/gentamicin/doxycycline (14/54, 25.9%) and potassium penicillin/gentamicin (10/54, 18.5%). Regional limb perfusion was performed preoperatively 31/54 (57.4%) and postoperatively 7/54 (13%). Survival to dismissal was 98.1% (53/54 horses) with one horse euthanized due to support limb laminitis. No association was identified between antibiotic selection or duration (1–3 vs. > 3 days), pre‐operative regional antibiotic perfusion, intraoperative antibiotic lavage or anaesthetic time (< or > 3 h) and SSI; however, modelling was complicated by quasi‐complete or complete separation of the data. Bayesian analysis (but not frequentist analysis) indicated an association between post‐operative regional antibiotic perfusion and SSI. Limitations include the retrospective nature of data collection and the low rate of infection overall. Conclusions: The prevalence of SSI in this population was lower than that in previous reports of equine orthopaedic internal fixation. There was no difference in SSI rate in cases administered systemic antibiotics for 1–3 days or >3 days, or for those horses that did or did not receive preoperative regional antibiotic perfusion. [ABSTRACT FROM AUTHOR]

Case Description-A 7-year-old mixed-breed stallion was admitted because of colic. Clinical Findings-Entrapment of the left colon in the renosplenic space was diagnosed via rectal palpation and ultrasonographic examination, despite a renosplenic space ablation 6.5 years earlier. Treatment and Outcome-The renosplenic entrapment was corrected with a combination of phenylephrine administration, rolling, and ballottement of the horse's abdomen during general anesthesia. The following week, left flank laparoscopic renosplenic space ablation was performed with the horse standing. On examination of the previous surgical site, only 4 bands of fibrous adhesion remained of the original space ablation. The renosplenic space was again closed by suturing the perirenal fascia and renosplenic ligament to the splenic capsule. The horse was discharged from the hospital and recovered at home. No complications or recurrence of entrapment was reported following the procedure. Clinical Relevance-There have been no previous reports of recurrence of renosplenic entrapment following procedures to permanently ablate the renosplenic space. Recurrence in this patient may be attributed to the horse's young age at the time of initial surgery or inadequate size or spacing of the sutures through the perirenal fascia and splenic capsule. [ABSTRACT FROM AUTHOR]

Case Description - An 11-year-old Quarter Horse stallion was admitted for intermittent hemospermia of 4 years' duration. Clinical Findings - A linear vertical defect had been detected endoscopically following multiple episodes of hemospermia on the caudodorsal convex surface of the urethra at the level of the ischial arch. Treatment and Outcome - When sexual rest alone did not result in complete healing of the urethral defect, a subischial urethrotomy and buccal mucosal urethroplasty were performed. The surgical site healed without complication. Four months of sexual rest was recommended after surgery. Repeat endoscopy at 4 months allowed inspection of the urethral graft site. Following endoscopic examination, resumption of semen collection was recommended on the basis of the apparent healing at the urethral defect site. Hemospermia did not reoccur following surgical repair. Clinical Relevance - Buccal mucosal urethroplasty resulted in a favorable outcome in a stallion with recurrent hemospermia. Buccal mucosal urethroplasty may be a useful surgical option in stallions that have hemospermia secondary to a urethral defect and do not heal with sexual rest alone. [ABSTRACT FROM AUTHOR]

Objective-To compare efficacy and safety of paste formulations of firocoxib and phenylbutazone in horses with naturally occurring osteoarthritis. Design-Randomized controlled clinical trial. Animals-253 client-owned horses with naturally occurring osteoarthritis. Procedures-Horses were treated with firocoxib (0.1 mg/kg [0.045 mg/lb], PO, q 24 h) or phenylbutazone (4.4 mg/kg [2 mg/lb], PO, q 24 h) for 14 days. Physical examinations and lameness evaluations were performed prior to treatment and after 7 and 14 days. Clinical improvement was defined as a reduction of at least 1 lameness grade or a combined reduction of at least 3 points in scores for pain during manipulation or palpation, joint swelling, joint circumference, and range of motion. Results-Proportion of horses clinically improved on day 14 for the firocoxib group (104/1 23 [84.6%]) was not significantly different from the proportion for the phenylbutazone group (103/119 [86.6%]). Proportion of horses that were improved on day 14 was significantly greater for horses treated with firocoxib than for horses treated with phenylbutazone with regard to score for pain on manipulation or palpation (P = 0.028), joint circumference score (P = 0.026), and range of motion score (P = 0.012), but not for overall lameness score or joint swelling score. No direct treatment-related adverse effects were detected during the study. Conclusions and Clinical Relevance-Results suggested that overall clinical efficacy of a paste formulation of firocoxib in horses with naturally occurring osteoarthritis was comparable to efficacy of a paste formulation of phenylbutazone. [ABSTRACT FROM AUTHOR]

Nymphophilus minckleyi is a hydrobiid snail endemic to the freshwater spring ecosystem of Cuatro Ciénegas, Mexico. We used seven allozyme loci to examine the genetic substructure of N. minckleyi from 14 sites (subpopulations) in the basin and to test the hypothesis that spring pools in Cuatro Ciénegas are separated into seven hydrologically distinct drainages. Hierarchical F-statistics suggest significant population structure exists among the fourteen populations but not among the seven proposed drainages. Cluster analysis of Nei's genetic distance did not show populations grouping according to drainages, although it did reveal alternative clusters. We found two distinct morphotypes that were supported as genetically distinct groups by the allozyme data. Genetic studies of vagile species in desert spring ecosystems can be used to reveal hydrologic connections and identify genetically unique sub-populations. [ABSTRACT FROM AUTHOR]

Background: Prophylactic perioperative antimicrobial protocols in equine synovial endoscopy have been described but not compared with respect to post‐operative outcomes and complications. Increasing antimicrobial resistance in equine practice and interest in promoting judicious use of antimicrobials has prompted reevaluation of drug selection and dosing strategies. Objectives: To determine the frequency of and compare post‐operative complications following elective synovial endoscopy between horses receiving different perioperative antimicrobial protocols. Methods: Records from the Colorado State University Veterinary Teaching Hospital were evaluated (2014–2018) and equine patients undergoing elective synovial endoscopy were identified. Patients undergoing endoscopy for sepsis or internal fixation were excluded. Patient signalment, clinician, joint and limb involved, perioperative antimicrobial regimen, number endoscopic portals and closure technique, and post‐operative complications including incidence of joint infection were recorded. Generalized linear models were used to estimate the odds of post‐operative complications. Results: Elective synovial endoscopies of 516 horses in 537 procedures evaluating 761 synovial structures were performed. No horses developed post‐operative septic synovitis. Administration of post‐operative antimicrobials, type used and patient sex were all significantly associated with increased risk of complications, which were predominantly gastrointestinal‐related. Complication rates in horses receiving a single preoperative dose of cefazolin were lower than in horses receiving potassium penicillin, gentamicin or multiple doses. Complication rates were lower in females compared to castrated or intact males. Other factors evaluated (breed, age, surgeon, anaesthesia duration or hospitalization, joint/limb operated, number endoscopic portals) were not associated with increased risk of complications post‐operatively in this case population. Conclusions: Prophylactic perioperative antimicrobial protocols in equine practice deserve periodic reconsideration due to increased antimicrobial resistance. Prolonged antimicrobial usage beyond the time of surgery was unnecessary to prevent septic synovitis following synovial endoscopy in this case population and was furthermore associated with an increased risk of gastrointestinal complications. [ABSTRACT FROM AUTHOR]

CASE DESCRIPTION A 6-year-old Quarter Horse gelding used for barrel racing was evaluated for acute onset of non-weight-bearing lameness of the left hind limb following strenuous exercise. CLINICAL FINDINGS Nuclear scintigraphic imaging revealed focal increased radiopharmaceutical uptake centrally within the left talus. Subsequent standard radiographic and ultrasonographic examinations of the tarsus failed to identify the cause of the increased radiopharmaceutical uptake; however, the lameness was definitively localized to the tarsocrural joint by intra-articular anesthesia. Subsequent MRI sequences of the left tarsus revealed an incomplete fracture of the talus that extended distally from the trochlear groove and evidence of maladaptive stress remodeling of the trochlear groove of the talus and distal intermediate ridge of the tibia. TREATMENT AND OUTCOME The horse was treated conservatively, with management consisting of stall confinement, physical rehabilitation, therapeutic laser therapy, and intraarticular autologous conditioned serum administration. The lameness resolved, and the horse was competing at its previous level within 15 months after lameness onset. CLINICAL RELEVANCE Although rare, incomplete fracture of the talus should be considered as a differential diagnosis for horses that develop acute hind limb lameness following strenuous exercise, especially when that exercise involves abrupt changes in direction while the horse is traveling at maximal speed. Acquisition of additional oblique projections during radiographic evaluation of the tarsus might be useful for identification of such fractures, but definitive diagnosis may require advanced diagnostic imaging modalities such as CT and MRI. Horses with incomplete fractures of the talus can be successfully treated with conservative management. [ABSTRACT FROM AUTHOR]

Case Description: An 18-year-old Paint stallion (horse 1) and a 17-year-old Morgan gelding (horse 2) were evaluated because of an acute onset of severe unilateral forelimb lameness. Clinical Findings: Both horses were unable to bear weight on the affected forelimb and had a dropped elbow appearance. Radial nerve paralysis, triceps myopathy, and fractures of the humerus and ulna were ruled out. The caudal aspect of the affected antebrachium of each horse was very firm to palpation and became firmer when weight was shifted onto the limb. Ultrasonographic examination revealed swelling and suspected intramuscular hemorrhage of the caudal antebrachial muscles. On the basis of clinical examination and diagnostic imaging findings, both horses had antebrachial compartment syndrome diagnosed. Lameness did not substantially improve with medical treatment in either horse. Treatment and Outcome: Caudal antebrachial fasciotomy was performed in each horse. Following sedation and local anesthetic administration, a bistoury knife was inserted through small incisions to perform fasciotomy. Horses remained standing throughout the procedure and were immediately able to bear weight on the affected limb without signs of discomfort. Horse 1 developed colitis and horse 2 developed a mild incisional infection, but both fully recovered and returned to their previous activities. Clinical Relevance: Antebrachial compartment syndrome is a rare cause of severe unilateral forelimb lameness and should be considered as a differential diagnosis in horses with a dropped elbow appearance. Both horses of this report had a successful outcome following antebrachial fasciotomy. [ABSTRACT FROM AUTHOR]

Behavioral studies have often examined parental care by measuring phenotypic plasticity of behavior within a species. Phylogenetic studies have compared parental care among species, but only at broad categories (e.g., care vs. no care). Here we provide a detailed account that integrates phylogenetic analysis with quantitative behavioral data to better understand parental care behavior in the Cuatro Ciénegas cichlid, Herichthys minckleyi. We found that H. minckleyi occurs in a clade of sexually monochromatic or weakly dichromatic monogamous species, but that male and female H. minckleyi have dramatically different reproductive coloration patterns, likely as a result of sexual selection. Furthermore, we found that males are polygynous; large males guard large territories, and smaller males may attempt alternative mating tactics (sneaking). Finally, compared to the closely related monogamous Rio Grande cichlid, H. cyanoguttatus, males of H. minckleyi were present at their nests less often and performed lower rates of aggressive offspring defense, and females compensated for the absence of their mates by performing higher levels of offspring defense. Body color, mating system, and parental care in H. minckleyi appear to have evolved after it colonized Cuatro Ciénegas, and are likely a result of evolution in an isolated, stable environment. [ABSTRACT FROM AUTHOR]

Accurate establishment of baseline conditions is critical to successful management and habitat restoration. We demonstrate the ability to robustly estimate historical fish community composition and assess the current status of the urbanized Barton Creek watershed in central Texas, U.S.A. Fish species were surveyed in 2008 and the resulting data compared to three sources of fish occurrence information: (i) historical records from a museum specimen database and literature searches; (ii) a nearly identical survey conducted 15 years earlier; and (iii) a modeled historical community constructed with species distribution models (SDMs). This holistic approach, and especially the application of SDMs, allowed us to discover that the fish community in Barton Creek was more diverse than the historical data and survey methods alone indicated. Sixteen native species with high modeled probability of occurrence within the watershed were not found in the 2008 survey, seven of these were not found in either survey or in any of the historical collection records. Our approach allowed us to more rigorously establish the true baseline for the pre-development fish fauna and then to more accurately assess trends and develop hypotheses regarding factors driving current fish community composition to better inform management decisions and future restoration efforts. Smaller, urbanized freshwater systems, like Barton Creek, typically have a relatively poor historical biodiversity inventory coupled with long histories of alteration, and thus there is a propensity for land managers and researchers to apply inaccurate baseline standards. Our methods provide a way around that limitation by using SDMs derived from larger and richer biodiversity databases of a broader geographic scope. Broadly applied, we propose that this technique has potential to overcome limitations of popular bioassessment metrics (e.g., IBI) to become a versatile and robust management tool for determining status of freshwater biotic communities. [ABSTRACT FROM AUTHOR]

Assesses the long-term clinical outcome of horses with distal tarsal osteoarthritis (OA) in which a three-drill-tract technique was used to induce arthrodesis of the affected joints. Preoperative or postoperative factors associated with outcome; Complications associated with the technique; Likelihood that horses with advanced distal tarsal OA will have poorer outcomes.

Resource polymorphisms, or morphological variations related to resource use, are common in fishes and are thought to be a possible step in speciation. This study experimentally tests the hypothesis that fitness (as estimated by growth rates) is increased by the presence of multiple trophic morphotypes (or morphs) within a population. Cage experiments were used to quantify the intraspecific competitive interactions between morphs of the polymorphic cichlid Herichthys minckleyi in Cuatro Ciénegas, Mexico. Results suggest that competition is reduced between morphs in mixed-morph treatments relative to equal-density single-morph treatments. Field studies revealed that the morphs feed in different microhabitats and use different feeding behaviors within these microhabitats. These results suggest that the polymorphism is maintained in the population because it decreases competition between the morphs, and that differences in feeding behavior facilitate resource partitioning. [ABSTRACT FROM AUTHOR]

Though adults and older juveniles of some species are commonly encountered in freshwater reaches of coastal streams and rivers, pipefishes in general are believed to be either amphidromous or marine. In 1992, Gulf pipefish (Syngnathus scovelli) were reported in Lake Texana, a reservoir on the Navidad River near Edna, Jackson County, Texas. In June 2011, we collected an adult male with embryos and a juvenile from the same lake. This strongly suggests reproduction and persistence of the population at Lake Texana, which does not have access to saline waters. Though presence of a viable, reproducing population was not absolutely confirmed this appears likely to be the first known landlocked, freshwater population of any species of pipefish. [ABSTRACT FROM AUTHOR]