Oral trazodone results in quantifiable sedation but does not result in a xylazine-sparing effect in healthy adult horses
Year: 2024
Type: article
Abstract: OBJECTIVE: To evaluate sedation and IV xylazine requirements to achieve 45% of baseline head height above ground measurements following oral (PO) administration of 2 trazodone dosages. METHODS: 8 healthy, adult mares of various weights and breeds belonging to a university teaching herd were utilized in a blinded, crossover study design. Horses were randomly assigned to 1 of 3 PO treatments: control (no trazodone), trazodone at 3 mg/kg (low dose [LD]), or trazodone at 6 mg/kg (high dose [HD]). Before treatment, cardiac auscultation, EquiSed sedation score, and head height above ground (HHAG; cm) measurements were performed (baseline) followed by feeding of the treatment mixture. After 120 minutes, sedation score and HHAG were recorded. Xylazine was administered IV (0.25 mg/kg bolus followed by 0.1 mg/kg/min) until HHAG reached 45% of baseline or a total dose of 1 mg/kg was reached. Individual data for xylazine dosage, sedation scores, and HHAG were analyzed using mixed linear models with repeated measures. RESULTS: Sedation scores were significantly improved (LD, P = .045; HD, P = .01) and HHAG was lowered (LD, P = .045; HD, P = .09) by trazodone administration. Xylazine dose requirements were increased by LD trazodone administration (increase of 0.26 ± 0.26 mg/kg; P = .03) and unchanged by HD (increase of 0.13 ± 0.25 mg/kg; P = .38). CONCLUSIONS: Oral trazodone administration increases quantifiable sedation in horses. Xylazine requirements are significantly increased by LD trazodone administration. CLINICAL RELEVANCE: Oral administration of LD trazodone may increase xylazine requirements. Further clinical studies are required to fully assess the clinical relevance of this finding on other parameters such as cardiovascular physiology.
Institution: University of Wisconsin–Madison
Language: English
Subfield: Small Animals
Field: Veterinary
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W4402309943