Partial ceratohyoidectomy as surgical treatment for horses with temporohyoid osteoarthropathy: 10 cases (2010-2021).

OBJECTIVE: To describe outcomes of horses with temporohyoid osteoarthropathy (THO) treated with partial ceratohyoidectomy. ANIMALS: 10 client-owned horses. PROCEDURES: Medical records from 2 institutions were examined for records of horses with THO treated with partial ceratohyoidectomy between 2010 and 2021. History, signalment, clinical signs, diagnostics, medications, and surgery-related details were recorded. Horses with a minimum of 6 months follow-up were recruited for neurologic and imaging examinations in the hospital or field where radiography of the basihyoid-ceratohyoid articulation were performed along with CT, when available. RESULTS: 10 horses with THO were included (9 unilateral; 1 bilateral). Nine planned partial ceratohyoidectomies were performed in 8 horses, whereas 2 horses had preoperatively planned complete ceratohyoidectomies transitioned to partial ceratohyoidectomies during surgery due to intraoperative complications. Postoperative complications occurred mostly in transitioned surgeries (obstructed airway, tongue mobility issues, and incisional hemorrhage), whereas only 1 horse with a planned ceratohyoidectomy had postoperative complication of rhabdomyolysis. All complications resolved before hospital discharge. Neurologic signs improved in all 10 horses, with 2 showing complete resolution. Nine horses were available for radiographic follow-up, 6 of which also had head CT scans. A space between the ceratohyoid and basihyoid bones was measurable on radiography in all 9 horses, and was confirmed on CT. Three horses demonstrated proliferation of either ceratohyoid or basihyoid bones. The 9 horses with unilateral disease returned to previous work, and the horse with bilateral disease was retired. CLINICAL RELEVANCE: Partial ceratohyoidectomy is a surgical option for treatment of THO that provides similar clinical outcomes to published reports on ceratohyoidectomy.

Characteristics and Sodium Pentobarbital Concentrations of Equine Mortality Compost Piles in the Upper Midwest.

Recent changes in rendering availability for chemically-euthanized animals have created a need to explore composting as an equine mortality management method. The objectives of this study were to evaluate equine mortality composting in the Upper Midwest during fall and spring, document sodium pentobarbital concentrations throughout the process, and determine nutrient content of finished compost. During each season, four horses were euthanized by intravenous administration of sodium pentobarbital. Carcasses were positioned at the center of a woodchip and shavings base and covered with a 2:1 mixture of horse stall waste and cattle feedlot waste. Data loggers were placed at 46- and 91cm depths to record pile temperatures every 8 hours. At turning (44-50 days) and trial conclusion (181-216 days), compost piles were sampled for sodium pentobarbital and nutrient composition. Piles contained large bones after 6 months of composting. Sodium pentobarbital remained detectable at trial conclusion (<0.002-1.49 mg kg1 dry matter); however, composting reduced the estimated quantities of sodium pentobarbital by ≥94% (P ≤ .001). Compost from each season met ideal land application values for organic matter (45%-48%), pH (7.3-7.6), and electrical conductivity (3.3-3.4 mm hos cm-1). Low NPK and high C:N ratio (20-30) indicate compost could partially replace synthetic fertilizers when land applied. These findings suggest equine mortality composting is an effective management practice during fall and spring in the Upper Midwest. While remaining sodium pentobarbital residues were minimal, further research is needed to determine environmental implications of composting chemically-euthanized equines.

Owner and Veterinarian Perceptions of Equine Euthanasia and Mortality Composting.

Challenges associated with burial, rendering, and cremation have forced horse owners to seek alternative mortality disposal methods. While equine mortality composting has been successfully demonstrated, industry-wide adoption has been limited. Therefore, evaluation of horse owners' and veterinarians' perceptions and experience with mortality composting is needed. Two surveys were developed to evaluate industry practices and decisive factors regarding equine euthanasia and mortality disposal methods. Each survey was designed for a separate audience: horse owners or veterinarians serving equines. The surveys were advertised as weblinks on relevant Facebook pages, e-newsletters, and email listservs. Data were analyzed using bivariate and multivariate models for associations and factors influencing decisions surrounding composting. The surveys yielded 1,225 and 244 usable responses from horse owners and veterinarians, respectively. Respondent demographics were consistent with previous survey reports for horse owners and veterinarians in the United States with a majority being female between 41 and 60 years of age with long-term industry involvement. Horse owners (86%) and veterinarians (84%) that preferred chemical euthanasia tended to prefer burial (58% and 42%, respectively) over other mortality disposal methods. Only 12% of horse owner respondents had ever tried composting and only 25% of veterinarian respondents had ever recommended composting. Horse owner (47%) and veterinarian (67%) respondents indicated they would be more open to trying and recommending mortality composting if more scientific research were available. Equine mortality composting shows potential as a primary disposal method for the equine industry. Research and educational programs are key to industry-wide acceptance of equine mortality composting.

Transient Fanconi syndrome in Quarter horses.

Two Quarter horses with weight loss had glucosuria, euglycemia, and a mild metabolic acidosis suggesting a proximal renal tubular defect. Further testing revealed transient generalized aminoaciduria, lactic aciduria, and glucosuria, indicating Fanconi syndrome. Both horses recovered with supportive therapy. This is the first report of acquired Fanconi syndrome in horses.

Syndrome de Fanconi transitoire chez des chevaux Quarter horse. Deux chevaux Quarter horse ayant subi une perte de poids étaient atteints de glucosurie, d'euglycémie et d'une acidose métabolique légère suggérant un défaut tubulaire rénal proximal. De nouveaux tests ont révélé une amino-acidurie, une acidurie lactique et une euglycémie généralisée transitoire, indicatif du syndrome de Fanconi. Les deux chevaux se sont rétablis avec une thérapie de soutien. Il s'agit du premier rapport du syndrome de Fanconi acquis chez les chevaux.(Traduit par Isabelle Vallières).