K. Kersh

Equine Multiple Acyl‐CoA Dehydrogenase Deficiency (MADD) Associated with Seasonal Pasture Myopathy in the Midwestern United States

BACKGROUND Seasonal pasture myopathy (SPM) is a highly fatal form of nonexertional rhabdomyolysis that occurs in pastured horses in the United States during autumn or spring. In Europe, a similar condition, atypical myopathy (AM), is common. Recently, a defect of lipid metabolism, multiple acyl-CoA dehydrogenase deficiency (MADD), has been identified in horses with AM. OBJECTIVE To determine if SPM in the United States is caused by MADD. ANIMALS Six horses diagnosed with SPM based on history, clinical signs, and serum creatine kinase activity, or postmortem findings. METHODS Retrospective descriptive study. Submissions to the Neuromuscular Diagnostic Laboratory at the University of Minnesota were reviewed between April 2009 and January 2010 to identify cases of SPM. Inclusion criteria were pastured, presenting with acute nonexertional rhabdomyolysis, and serum, urine, or muscle samples available for analysis. Horses were evaluated for MADD by urine organic acids, serum acylcarnitines, muscle carnitine, or histopathology. RESULTS Six horses had clinical signs and, where performed (4/6 horses), postmortem findings consistent with SPM. Affected muscle (4/4) showed degeneration with intramyofiber lipid accumulation, decreased free carnitine concentration, and increased carnitine esters. Serum acylcarnitine profiles (3/3) showed increases in short- and medium-chain acylcarnitines and urinary organic acid profiles (3/3) revealed increased ethylmalonic and methylsuccinic acid levels, and glycine conjugates, consistent with equine MADD. CONCLUSIONS AND CLINICAL IMPORTANCE Similar to AM, the biochemical defect causing SPM is MADD, which causes defective muscular lipid metabolism and excessive myofiber lipid content. Diagnosis can be made by assessing serum acylcarnitine and urine organic acid profiles.

The use of intraluminal stents for tracheal collapse in two horses: Case management and long-term treatment

Summary Tracheal collapse is an uncommon clinical disorder in horses but when present can be difficult to correct. Various medical and surgical procedures to correct tracheal collapse have been described in horses with variable success. Recently, the use of an intraluminal stent has been described as a treatment for tracheal collapse in a miniature horse. The long-term management, utilising intraluminal stents, in 2 miniature horses with tracheal collapse is presented here. In particular, various complications as a result of intraluminal stent placement are described, the most persistent being the formation of granulation tissue at various regions of the stents. Multiple methods of combating granulation tissue in this situation also are discussed.

Retrospective evaluation of facilitated pastern ankylosis using intra‐articular ethanol injections: 34 cases (2006–2012)

REASONS FOR PERFORMING STUDY While surgical arthrodesis is the treatment of choice for osteoarthritis of the proximal interphalangeal joint, some clients are unable to pursue surgery due to costs. A more economical technique was sought using intra-articular ethyl alcohol injections to facilitate ankylosis. OBJECTIVES To describe the technique and outcome of intra-articular ethyl alcohol injections for facilitated ankylosis of proximal interphalangeal joints with osteoarthritis. METHODS As a retrospective case series, the medical records (2006-2012) of clinical cases diagnosed with proximal interphalangeal joint osteoarthritis treated with intra-articular ethyl alcohol injections were reviewed. Cases with follow-up of at least 6 months were included. Technique and outcome were determined. Evaluation of outcome was assessed using return to previous performance or intended use and owner satisfaction as the indicators of success. Soundness and level of work are also reported. RESULTS Thirty-four horses were included in the study. At the time of follow-up, 17 horses (50%) were sound, while 13 horses (38%) were improved but not sound. One horses lameness was unchanged, and 3 horses were lost to follow-up. The median time until horses became sound or returned to work was 8 months. Six horses had complications, 4 of which were mild and transient. CONCLUSIONS AND POTENTIAL RELEVANCE The use of intra-articular ethyl alcohol in the proximal interphalangeal joint in horses affected by osteoarthritis appears to be a viable method for facilitated ankylosis if surgical management is not an option.

Outcome of horses undergoing navicular bursotomy for the treatment of contaminated or septic navicular bursitis: 19 cases (2002–2016)

BACKGROUND Contaminated or septic navicular bursitis has been reported to have a guarded prognosis after surgical treatment with navicular bursotomy only. In our experience, the use of navicular bursotomy for the treatment of this disease in combination with systemic and local delivery of antimicrobials can provide a good prognosis, even in horses with chronic disease. OBJECTIVE To report the outcome of horses undergoing navicular bursotomy for the treatment of contaminated or septic navicular bursitis. STUDY DESIGN Descriptive case series. METHODS Navicular bursotomy was performed in combination with systemic and local antimicrobial therapies. Medical records (2002-2016) were reviewed. Follow-up information was obtained from owners or referring veterinarians. Horse outcome was divided into two groups. A successful outcome (Group 1) was assigned to horses that were able to return to the same level of use or performance as before contamination/infection. A satisfactory outcome (Group 2) was assigned to horses that survived but did not return to their previous function or level of performance. RESULTS All horses survived to hospital discharge. Follow-up was obtained from 4 months to 12.75 years after surgery. Sixteen horses were able to return to their previous level of use (84.2%) and three horses were able to return to a lower level of performance or were pasture sound (15.8%). All 19 owners were satisfied with the outcome. MAIN LIMITATIONS Small sample size and retrospective nature of the study. Follow-up was limited to telephone contact with owners and referring veterinarians, and there is potential for recall bias. CONCLUSIONS Navicular bursotomy in combination with systemic and local antimicrobial therapies is an effective treatment for contaminated or septic navicular bursitis. The success rate in this population makes navicular bursotomy worthy of consideration in cases of contaminated or septic navicular bursitis, especially with chronicity and/or where equipment or expertise for bursoscopy is unavailable.

Efficacy of Teaching the Gambee Suture Pattern Using Simulated Small Intestine versus Cadaveric Small Intestine

OBJECTIVE To determine if instruction using simulated small intestine (SSI) is as effective as using cadaveric small intestine to teach the Gambee suture pattern to second year veterinary students. STUDY DESIGN Prospective, randomized, blinded study. SAMPLE POPULATION Second year veterinary students (n=59). METHODS Students were randomly assigned to groups using SSI or equine cadaver small intestine (CSI) to learn the Gambee suture pattern. The same educator, an experienced surgical instructor, instructed all students. Instruction consisted of verbal description of the technique with a schematic diagram followed by a demonstration. Students then practiced the technique with supervision and verbal feedback. One week later, 3 board certified surgeons experienced in surgical instruction evaluated each student suturing equine CSI and scored them using a rubric developed and validated for surgical skills assessment. RESULTS Fifty-nine students were enrolled (4 students were absent for the lab during which the assessment was performed; 55 students were available for evaluation). Of the 55 students evaluated, 26 were in the SSI group and 29 were in the CSI group. There was no significant difference between CSI and SSI groups in ability to perform the Gambee suture pattern using equine CSI 1 week following training. CONCLUSION SSI is as effective as equine cadaveric small intestine tissue to teach the Gambee suture pattern to second year veterinary students. If cadaver tissue is unavailable or undesirable, SSI could be used to instruct suture placement techniques.

Tenotomy of the semitendinosus muscle under standing sedation versus general anesthesia: Outcomes in 20 horses with fibrotic myopathy

OBJECTIVE To compare outcomes after semitendinosus tenotomy performed under standing sedation versus general anesthesia. STUDY DESIGN Retrospective case series. SAMPLE POPULATION 20 horses with fibrotic myopathy of the semitendinosus muscle. METHODS Medical records (2002-2015) of horses undergoing tenotomy of the semitendinosus muscle for the treatment of fibrotic myopathy were reviewed. Signalment, history, affected muscles, restrain method, surgical procedures, and short-term outcome as well as complications were retrieved from records. Long-term outcome (gait and athletic function) was assessed at least 6 months postoperatively by conversation with the owners. Pearsons χ2 statistical analysis was used to compare restrain method and affected muscles with overall outcome. Significance was set at P < .05. RESULTS Tenotomy of the semitendinosus muscle was performed under standing sedation in 8 horses and under general anesthesia in 12 horses. Follow-up period ranged from 9 months to 10 years. Gait was improved to variable degrees in 8 of 14 horses when the semitendinosus muscle alone was affected and in 4 of 6 horses when both the semitendinosus and semimembranosus muscles were involved (P = .11). Six of 8 horses treated under standing sedation and 6 of 12 horses treated under general anesthesia exhibited some improvement in the characteristic fibrotic gait (P = .4473). Five of 6 athletic horses treated under standing sedation and 6 of 9 athletic horses treated under general anesthesia returned to their preinjury level of athleticism. Horses treated under standing sedation had no incisional complications; 2 of 12 horses treated under general anesthesia exhibited incisional drainage. CONCLUSION Tenotomy of the semitendinosus muscle in horses with fibrotic myopathy leads to similar improvement in gait, whether performed under standing sedation or general anesthesia.