Outcome of bilateral equid laparoscopic ovariectomies.

OBJECTIVE: To assess outcomes and behavior changes associated with bilateral laparoscopic ovariectomies. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Fifty-one equids. METHODS: Medical records were evaluated from equid bilateral laparoscopic ovariectomies from January 2012 to October 2018 with a potential of 6 months follow-up. Follow-up information obtained by telephone interviews included behavior before and after surgery. Likelihood ratio chi-square tests and odds ratios (OR) with 95% CI were calculated where applicable, with statistical significance at p < .05. RESULTS: Bilateral ovariectomy was performed in 51 cases, with elective (no pathologic ovaries) ovariectomies performed in 41/51 cases. Occasional estrus-like behavior was observed postoperatively in 14/51 (27%) mares, but the behavior was mild and manageable in all cases. There was no age effect on outcome in all bilateral (p = .56) or elective only (p = .36) cases. In 37/41 (90%) elective cases, improvement was observed in the reason for presentation. Some response to altrenogest administration for behavior modification was observed preoperatively in 12/18 (67%) elective cases. Response to altrenogest was not associated with (p = .31) or able to predict a beneficial response to surgery (OR = 5.5; 95% CI = 0.38-78.57; p = .21). CONCLUSION: Response to altrenogest in elective cases may not predict behavioral outcome with ovariectomy. Occasional estrus-like behavior in mares postoperatively was not problematic for any owners. Bilateral ovariectomy is a viable treatment option for owners seeking to alleviate undesirable behavior in mares. CLINICAL SIGNIFICANCE: This study should aid veterinarians and horse owners in case selection for bilateral ovariectomy.

Evaluation of a Permanent Synthetic Osteochondral Implant in the Equine Medial Femoral Condyle.

OBJECTIVE: To evaluate bone ingrowth, integration, and tolerance of a synthetic osteochondral implant in the medial femoral condyle (MFC) of normal horses. STUDY DESIGN: Experimental study. ANIMALS: Adult horses (n = 6). METHODS: Horses were anesthetized and bilateral femorotibial arthrotomies were performed for placement of 1 implant consisting of polycarbonate urethane with a titanium base in 1 MFC. The contralateral MFC served as a sham-operated control without reaming of cartilage or subchondral bone. Lameness evaluations and radiographs were performed pre-operatively with subsequent monthly lameness exams and radiographs at 6 months. Synovial fluid was collected for analysis from the adjacent femoropatellar joints pre-operatively and at several intervals post-operatively. Horses were euthanatized 6 months post-operatively. Stifles were harvested for gross and histologic evaluations. RESULTS: Two horses were never lame, 2 were mildly lame, and 1 exhibited moderate lameness. Synovial fluid inflammatory parameters of the adjacent femoropatellar joints were not significantly different. No significant changes occurred radiographically over time in either stifle. Histologic assessment of synovium from the medial femorotibial joint revealed no differences in inflammatory changes between implant and sham stifles. Integration and osteoconductivity of the implant were graded as good in 4 and 3 of 5 specimens, respectively. Complications included joint sepsis resulting in euthanasia (1 horse), persistent lameness (1 horse), incisional seromas (4 horses), and incisional dehiscence (2 horses). CONCLUSION: Results of this pilot study indicate that the implant was compatible with placement in the MFC of normal horses. Implant design allowed bone ingrowth within the titanium base and provision of a synthetic articular surface.