Nicole A. I. Phillips

Objective: To determine the effect of a clinically relevant dose of trazodone on platelet count and function in healthy horses. Study design: Prospective, controlled, cross‐over study. Animals: Ten healthy horses. Methods: Horses were administered either 7 mg/kg trazodone orally in corn syrup or an equal amount of corn syrup (control), every 12 h for 2 weeks. After 2 weeks, horses underwent at least a 2‐week washout period before being administered the alternate treatment (trazodone or control). Blood was collected before the first treatment administration (day 0) and after 2 weeks of treatment for each phase of the study. Complete blood cell counts, platelet function assays, and plasma trazodone concentrations were assessed. Data were analyzed using repeated measures ANOVA with significance set at p < .05. Results: No differences in platelet count or tests of platelet function were observed at any time point after trazodone or control treatment. There were no adverse effects of trazodone administration appreciated on repeat physical examinations or daily ataxia scoring. Conclusions: No inhibitory effects of trazodone on platelet function in horses were detected. Clinical significance: This study suggests administration of oral trazodone at 7 mg/kg prior to surgery is unlikely to impair platelet function in healthy horses.

Objective: To report the clinical outcomes and survival time in horses undergoing treatment of guttural pouch mycosis. Methods: Client-owned horses with guttural pouch mycosis admitted between 2005 and 2024 for evaluation and treatment were identified by medical record search. Signalment, disease history, and surgical and treatment details were recorded. Owners were contacted for follow-up information. Results: 41 horses with guttural pouch mycosis were identified, of which 28 had epistaxis or a history of epistaxis on presentation. Thirty-five horses underwent surgical treatment, and the procedures included balloon catheter arterial occlusion, arterial embolization, arterial ligation, and pharyngeal fenestration. Six horses died or were euthanized in hospital, and 35 horses were discharged alive. Median time to follow-up was 377 weeks. Twenty-four of 35 horses discharged from the hospital were alive at follow-up, and 5 horses were euthanized for guttural-pouch-mycosis–related disease within 60 days of disease confirmation. The other 6 horses died of causes unrelated to guttural pouch mycosis. Epistaxis did not negatively impact survival. Horses with dysphagia on admission did not have lower survival time, and time to resolution of dysphagia varied from 6 to 12 months. Conclusions: The findings suggested that guttural pouch mycosis carries a good prognosis for short-term survival and fair to good prognosis for long-term survival following hospital-based treatment. Clinical Relevance: Treatment for horses with guttural pouch mycosis should not be withheld based on prognosis related to concurrent epistaxis or dysphagia.

Background: In horses, standing arthroscopy offers a valuable alternative to general anesthesia for the reduction of anesthetic-associated risks, and provides improved visualization in joints where access is facilitated by weightbearing. These techniques are particularly advantageous for patients with increased anesthetic risk or financial limitations. To the authors’ knowledge, the removal of osteochondral fragments from the distal interphalangeal joint in a standing, sedated horse using small-diameter arthroscopic equipment has not been previously reported. Case Presentation: A 7-year-old American Quarter Horse–Thoroughbred cross presented on referral for treatment of osteochondral fragmentation in the right fore distal interphalangeal joint. A standing arthroscopic approach to the distal interphalangeal joint was performed. In a weight-bearing position, debridement of the dorsal osteochondral fragments from the second and third phalanx was successfully completed, using a 2 mm NanoNeedle scope and 3.2 mm high-flow 10- degree cannula (Arthrex^®). At one year follow-up, the horse had returned to competition and was sound at veterinary examination. Conclusion: This case demonstrates the feasibility of standing NanoNeedle arthroscopy of the equine coffin joint with improved maneuverability, surgical ergonomics, and reduced iatrogenic injury compared to a standard rigid arthroscope. The successful execution of this technique effectively expands our collection of standing arthroscopic procedures in the equine patient.