Drug profile

The FDA adverse-event record for Ivermectin + Pyrantel

8,038 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Ivermectin + Pyrantel. See the species affected, top reactions, and outcomes below.

8,038
adverse-event reports
1.7%
death-coded share
Dog
most-reported species
2,155
Lack of efficacy (endoparasite) - heartworm - 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.
8,038
Total Reports
134
Deaths Reported
1.7%
Death Rate

Active Ingredients

IvermectinIvermectin + PyrantelPyrantel

Administration Routes

OralUnknownIntrathoracicUnassigned

Species Affected

Dog 7,638
Unknown 391
Cat 8
Human 1

Most Affected Breeds

Crossbred Canine/dog 1,308
Retriever - Labrador 866
Unknown 838
Shepherd Dog - German 391
Dog (unknown) 310
Pit Bull 262
Chihuahua 254
Retriever - Golden 253
Beagle 186
Boxer (German Boxer) 169

Most Reported Reactions

Lack of efficacy (endoparasite) - heartworm 2,155
Vomiting 1,217
INEFFECTIVE, HEARTWORM LARVAE 954
Lack of efficacy (endoparasite) - hookworm 604
Diarrhoea 504
UNPALATABLE 492
Lethargy (see also Central nervous system depression in 'Neurological') 420
Emesis (multiple) 330
INEFFECTIVE, HOOKS 310
Lack of efficacy (endoparasite) - roundworm NOS 228
Product Defect, General 219
Product problem 184

Outcome Breakdown

Ongoing
3,886 (50.8%)
Recovered/Normal
2,084 (27.3%)
Outcome Unknown
1,443 (18.9%)
Recovered with Sequela
98 (1.3%)
Euthanized
68 (0.9%)
Died
66 (0.9%)

Ivermectin + Pyrantel Adverse Event Insights

8,038 reports name Ivermectin + Pyrantel; 134 recorded a death outcome (1.7% of reported events, not a population-level mortality rate). Active ingredients: Ivermectin, Ivermectin + Pyrantel, Pyrantel. Administration routes: Oral, Unknown, Intrathoracic, Unassigned.

By species: Dog (7,638 reports), Unknown (391 reports), Cat (8 reports). By breed: Crossbred Canine/dog (1,308), Retriever - Labrador (866), Unknown (838).

Leading clinical signs: Lack of efficacy (endoparasite) - heartworm (2,155), Vomiting (1,217), INEFFECTIVE, HEARTWORM LARVAE (954), Lack of efficacy (endoparasite) - hookworm (604). Outcome, 7,645 coded reports: Ongoing leads at 50.8%.

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.