Matti McGeachie¹, Carrie Tooley², Dave C. Brodbelt¹, David B. Church¹, Dan G. O'Neill¹

¹The Royal Veterinary College, London, United Kingdom. ²Behavioural Referrals Veterinary Practice, Chester, United Kingdom

Objectives

To report frequency, demographic risk factors and clinical use of trazodone in dogs under UK primary veterinary care in 2023.

Methods

A cohort study of 2,283,895 dogs within VetCompass under UK primary veterinary care in 2023. Risk factor analysis used multivariable logistic regression modelling.

Results

Annual prevalence of trazodone use was 1.61% (95% CI 1.54–1.70). Male dogs had 1.37 times odds compared with females (95% CI 1.23–1.53). Neutered dogs had 1.59 times odds compared with entire dogs (95% CI 1.43-1.78). Dogs 2–<4-years-old had 2.57 times odds compared with dogs aged under 1 (95% CI, 1.98-3.35).  Belgian Shepherds (OR 4.18, 95% CI 2.26–7.75), Rottweilers (OR 1.81, 95% CI 1.11-2.96), and German Shepherds (OR 1.72, 95% CI 1.29-2.31) were predisposed compared to crossbreeds.

The most frequent contexts for trazodone use were to support nail clipping (11.99%) and vaccination (11.71%). Median doses were PRN 7.17 mg/kg (n=1013) and non-PRN 4.76 mg/kg per dose (n=295). The most frequently reported PRN regimen involved administering trazodone the night before and two hours prior to the fear-inducing event (30.21%). Daily use was most often 24 hourly (51.19%). Adverse effects were uncommon: sedation (2.7%) and vomiting (0.92%).

Statement: Impact/ Clinical Significance

Recognising breeds and demographic groups with higher odds of use may help clinicians identify patients needing behavioural or pharmacological support. Frequent use during nail-clipping and vaccination highlights routine procedures as stressors and opportunities for low-stress handling. Reported doses used provide prescribing benchmarks, though some dosing regimens may not align with trazodone pharmacokinetics. Overall, trazodone appears generally well tolerated.