Drug profile

The FDA adverse-event record for Ondansetron Hcl

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

147
adverse-event reports
39.5%
death-coded share
Dog
most-reported species
76
Vomiting - top reaction
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Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
147
Total Reports
58
Deaths Reported
39.5%
Death Rate

Active Ingredients

Ondansetron Hcl

Administration Routes

UnknownOralIntravenousSubcutaneous

Species Affected

Dog 129
Cat 18

Most Affected Breeds

Retriever - Labrador 25
Domestic Shorthair 10
Terrier - Bull - American Pit 8
Bulldog - French 7
Maltese 6
Mixed (Dog) 4
Shepherd Dog - Australian 4
Terrier - Yorkshire 4
Beagle 4
Siberian Husky 3

Most Reported Reactions

Vomiting 76
Lethargy (see also Central nervous system depression in 'Neurological') 57
Death by euthanasia 40
Anorexia 39
Elevated alanine aminotransferase (ALT) 36
Diarrhoea 36
Other abnormal test result NOS 31
Elevated total bilirubin 31
Elevated serum alkaline phosphatase (SAP) 31
Leucocytosis NOS 23
Elevated liver enzymes 22
Anaemia NOS 22

Outcome Breakdown

Ongoing
66 (44.6%)
Euthanized
40 (27.0%)
Recovered/Normal
19 (12.8%)
Died
18 (12.2%)
Outcome Unknown
5 (3.4%)

Ondansetron Hcl Adverse Event Insights

147 reports name Ondansetron Hcl; 58 recorded a death outcome (39.5% of reported events, not a population-level mortality rate). Active ingredient: Ondansetron Hcl. Administration routes: Unknown, Oral, Intravenous, Subcutaneous.

By species: Dog (129 reports), Cat (18 reports). By breed: Retriever - Labrador (25), Domestic Shorthair (10), Terrier - Bull - American Pit (8).

Leading clinical signs: Vomiting (76), Lethargy (see also Central nervous system depression in 'Neurological') (57), Death by euthanasia (40), Anorexia (39). Outcome, 148 coded reports: Ongoing leads at 44.6%.

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.