Drug profile

The FDA adverse-event record for Heartworm Preventative

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

69
adverse-event reports
7.2%
death-coded share
Dog
most-reported species
13
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.
69
Total Reports
5
Deaths Reported
7.2%
Death Rate

Active Ingredients

Heartworm Preventative

Administration Routes

OralUnknownSubcutaneousParenteral

Species Affected

Dog 69

Most Affected Breeds

Retriever - Labrador 11
Crossbred Canine/dog 10
Shepherd Dog - German 4
Retriever - Golden 4
Chihuahua 3
Schnauzer - Miniature 2
Terrier - Rat 2
Pit Bull 2
Great Pyrenees 2
Cattle Dog - Australian (blue heeler, red heeler, Queensland cattledog) 2

Most Reported Reactions

Vomiting 13
Lack of efficacy (endoparasite) - heartworm 13
Lethargy (see also Central nervous system depression in 'Neurological') 9
Emesis (multiple) 8
Diarrhoea 7
Weight loss 5
Elevated blood urea nitrogen (BUN) 5
Emesis 4
Elevated alanine aminotransferase (ALT) 4
Inappetence 4
Not eating 4
Ataxia 3

Outcome Breakdown

Recovered/Normal
27 (39.1%)
Ongoing
20 (29.0%)
Outcome Unknown
16 (23.2%)
Died
3 (4.3%)
Euthanized
2 (2.9%)
Recovered with Sequela
1 (1.4%)

Heartworm Preventative Adverse Event Insights

69 reports name Heartworm Preventative; 5 recorded a death outcome (7.2% of reported events, not a population-level mortality rate). Active ingredient: Heartworm Preventative. Administration routes: Oral, Unknown, Subcutaneous, Parenteral.

By species: Dog (69 reports). By breed: Retriever - Labrador (11), Crossbred Canine/dog (10), Shepherd Dog - German (4).

Leading clinical signs: Vomiting (13), Lack of efficacy (endoparasite) - heartworm (13), Lethargy (see also Central nervous system depression in 'Neurological') (9), Emesis (multiple) (8). Outcome, 69 coded reports: Recovered/Normal leads at 39.1%.

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.