Drug profile

The FDA adverse-event record for Ondansetron

515 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Ondansetron. See the species affected, top reactions, and outcomes below.

515
adverse-event reports
29.5%
death-coded share
Dog
most-reported species
129
Vomiting - top reaction
Verify with FDA CVM →
Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
515
Total Reports
152
Deaths Reported
29.5%
Death Rate

Active Ingredients

Ondansetron

Administration Routes

UnknownOralIntravenousParenteralSubcutaneousIntramuscularOtherTransdermal

Species Affected

Dog 379
Cat 133
Human 3

Most Affected Breeds

Domestic Shorthair 77
Retriever - Labrador 61
Retriever - Golden 27
Crossbred Canine/dog 17
Domestic Mediumhair 14
Pit Bull 12
Dog (unknown) 11
Boxer (German Boxer) 10
Domestic Longhair 10
Terrier (unspecified) 9

Most Reported Reactions

Vomiting 129
Lethargy (see also Central nervous system depression in Neurological) 119
Death by euthanasia 110
Diarrhoea 97
Not eating 94
Elevated alanine aminotransferase (ALT) 71
Decreased appetite 70
Abnormal ultrasound finding 68
Other abnormal test result NOS 62
Weight loss 61
Elevated total bilirubin 60
Anorexia 56

Outcome Breakdown

Ongoing
157 (30.5%)
Euthanized
110 (21.4%)
Recovered/Normal
105 (20.4%)
Outcome Unknown
100 (19.4%)
Died
42 (8.2%)
Recovered with Sequela
1 (0.2%)

Ondansetron Adverse Event Insights

515 reports name Ondansetron; 152 recorded a death outcome (29.5% of reported events, not a population-level mortality rate). Active ingredient: Ondansetron. Administration routes: Unknown, Oral, Intravenous, Parenteral.

By species: Dog (379 reports), Cat (133 reports), Human (3 reports). By breed: Domestic Shorthair (77), Retriever - Labrador (61), Retriever - Golden (27).

Leading clinical signs: Vomiting (129), Lethargy (see also Central nervous system depression in Neurological) (119), Death by euthanasia (110), Diarrhoea (97). Outcome, 515 coded reports: Ongoing leads at 30.5%.

Read these counts as reporting volume, not risk: per our methodology, a widely-prescribed drug will rack up more raw FDA reports in a given year than a rarely-used one at an identical true rate, so we recommend comparing within similar-exposure products rather than across the full 2025 catalog.

Source: FDA Center for Veterinary Medicine openFDA Animal & Veterinary Adverse Events (CVM AER) · 2025

Every figure on PlainBreed is rendered directly from FDA openFDA adverse event data, no number is typed in by an editor. This page draws directly on FDA openFDA data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.