Drug profile

The FDA adverse-event record for Unknown Heartworm Preventative

40 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Unknown Heartworm Preventative. See the species affected, top reactions, and outcomes below.

40
adverse-event reports
7.5%
death-coded share
Dog
most-reported species
20
Lack of efficacy (endoparasite) - heartworm - 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.
40
Total Reports
3
Deaths Reported
7.5%
Death Rate

Active Ingredients

Unknown Heartworm Preventative

Administration Routes

UnknownOral

Species Affected

Dog 40

Most Affected Breeds

Retriever - Labrador 9
Beagle 4
Collie - Border 3
Pit Bull 3
Shepherd Dog - German 3
Terrier - West Highland White 2
Crossbred Canine/dog 2
Dachshund (unspecified) 2
Terrier - Airedale 1
Doberman Pinscher 1

Most Reported Reactions

Lack of efficacy (endoparasite) - heartworm 20
Death by euthanasia 3
Gingival hyperplasia 3
Vomiting 3
Urinary tract infection 3
Polydipsia 2
Polyuria 2
Emesis 2
Diarrhoea 2
Other abnormal test result NOS 2
Lameness 2
Elevated liver enzymes 2

Outcome Breakdown

Ongoing
15 (37.5%)
Outcome Unknown
14 (35.0%)
Recovered/Normal
6 (15.0%)
Euthanized
3 (7.5%)
Recovered with Sequela
2 (5.0%)

Unknown Heartworm Preventative Adverse Event Insights

40 reports name Unknown Heartworm Preventative; 3 recorded a death outcome (7.5% of reported events, not a population-level mortality rate). Active ingredient: Unknown Heartworm Preventative. Administration routes: Unknown, Oral.

By species: Dog (40 reports). By breed: Retriever - Labrador (9), Beagle (4), Collie - Border (3).

Leading clinical signs: Lack of efficacy (endoparasite) - heartworm (20), Death by euthanasia (3), Gingival hyperplasia (3), Vomiting (3). Outcome, 40 coded reports: Ongoing leads at 37.5%.

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.