Drug profile

The FDA adverse-event record for Dewormer

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

44
adverse-event reports
20.5%
death-coded share
Dog
most-reported species
8
Death by euthanasia - 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.
44
Total Reports
9
Deaths Reported
20.5%
Death Rate

Active Ingredients

Dewormer

Administration Routes

OralUnknownTopical

Species Affected

Dog 24
Cat 17
Cattle 2
Horse 1

Most Affected Breeds

Domestic Shorthair 15
Crossbred Canine/dog 2
Retriever - Labrador 2
Cattle (other) 2
Dog (unknown) 2
Terrier - Bull - American Pit 2
Pit Bull 1
Domestic Mediumhair 1
Domestic Longhair 1
Bulldog 1

Most Reported Reactions

Death by euthanasia 8
Lateral recumbency 7
Vomiting 7
Muscle tremor 6
Bradypnoea 6
Decreased body temperature 6
Diarrhoea 4
Lack of efficacy - NOS 4
Lethargy (see also Central nervous system depression in Neurological) 4
Other abnormal test result NOS 3
Lack of efficacy (ectoparasite) - flea 3
Bloody diarrhoea 3

Outcome Breakdown

Outcome Unknown
15 (31.9%)
Recovered/Normal
11 (23.4%)
Ongoing
11 (23.4%)
Euthanized
8 (17.0%)
Died
2 (4.3%)

Dewormer Adverse Event Insights

44 reports name Dewormer; 9 recorded a death outcome (20.5% of reported events, not a population-level mortality rate). Active ingredient: Dewormer. Administration routes: Oral, Unknown, Topical.

By species: Dog (24 reports), Cat (17 reports), Cattle (2 reports). By breed: Domestic Shorthair (15), Crossbred Canine/dog (2), Retriever - Labrador (2).

Leading clinical signs: Death by euthanasia (8), Lateral recumbency (7), Vomiting (7), Muscle tremor (6). Outcome, 47 coded reports: Outcome Unknown leads at 31.9%.

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.