Veterinary surgery : VS2026; doi: 10.1111/vsu.70168

Trazodone administration does not affect platelet concentration or function in horses.

Phillips, NAI
·
Goggs, R
·
Pinn-Woodcock, TL
·
Colbath, AC

Abstract: To determine the effect of a clinically relevant dose of trazodone on platelet count and function in healthy horses. Methods: Prospective, controlled, cross-over study. Methods: 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. Conclusions: This study suggests administration of oral trazodone at 7 mg/kg prior to surgery is unlikely to impair platelet function in healthy horses.

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Publication Date: 2026-10-25 PubMed ID: 42928479DOI: 10.1111/vsu.70168Google Scholar: Lookup

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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

Overview

This study investigated whether administering the drug trazodone at a clinically relevant dose affects platelet count or function in healthy horses.
The results showed that trazodone administration did not alter platelet concentration or impair platelet function, suggesting it is safe to use in terms of platelet activity in horses.

Study Purpose

To evaluate the effect of oral trazodone, given at 7 mg/kg, on platelet numbers and function in horses.
To determine if trazodone affects blood clotting properties, which is important for the safety of using this drug before surgery.

Methods

Study design: A prospective, controlled, cross-over study.
Subjects: Ten healthy horses participated in the study.
Treatment protocol:
- Horses received oral trazodone at 7 mg/kg mixed in corn syrup every 12 hours for two weeks.
- For control phases, horses received the same volume of corn syrup without drug.
- After the first two-week treatment phase, horses had a washout period of at least two weeks before switching to the alternate treatment.
Blood sampling: Samples were taken before the first treatment (day 0) and after two weeks of treatment for each phase.
Evaluations performed:
- Complete blood cell counts to assess platelet concentration.
- Platelet function assays to assess how well platelets clump together and function.
- Plasma levels of trazodone to confirm drug exposure.
Data analysis: Repeated measures ANOVA was used to compare results over time and between treatments, with significance set at p < 0.05.

Results

No significant changes in platelet count were found after administration of trazodone compared to control treatment.
Platelet function tests showed no inhibition or impairment related to trazodone use.
Physical examinations and ataxia (coordination) scoring daily showed no adverse effects from trazodone.

Conclusions

Trazodone administered orally at 7 mg/kg twice daily for two weeks does not affect platelet concentration or function in healthy horses.
This suggests trazodone is unlikely to increase bleeding risk due to platelet dysfunction if given prior to surgery.
These findings support the safe use of trazodone for behavioral or other clinical indications without concern for platelet-related complications in healthy equine patients.

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APA

Phillips NAI, Goggs R, Pinn-Woodcock TL, Colbath AC. (2026). Trazodone administration does not affect platelet concentration or function in horses. Vet Surg. https://doi.org/10.1111/vsu.70168

Publication

Veterinary surgery : VS

ISSN: 1532-950X

NlmUniqueID: 8113214

Country: United States

Language: English

Researcher Affiliations

Phillips, Nicole A I

College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.

Goggs, Robert

College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.

Pinn-Woodcock, Toby L

College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.

Colbath, Aimee C

College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.

Grant Funding

American College of Veterinary Surgeons Foundation

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