Drug profile

The FDA adverse-event record for Heartguard

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

38
adverse-event reports
7.9%
death-coded share
Dog
most-reported species
13
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.
38
Total Reports
3
Deaths Reported
7.9%
Death Rate

Active Ingredients

Heartguard

Administration Routes

OralUnknown

Species Affected

Dog 38

Most Affected Breeds

Crossbred Canine/dog 8
Siberian Husky 4
Retriever - Labrador 4
Terrier - Bull - American Pit 4
Boxer (German Boxer) 2
Terrier - Jack Russell 2
Pug 2
Spaniel - Cocker English 1
Schnauzer (unspecified) 1
Terrier - Boston 1

Most Reported Reactions

Lack of efficacy (endoparasite) - heartworm 13
Seizure NOS 7
Vomiting 4
Ataxia 3
Diarrhoea 3
Lameness 2
Emesis (multiple) 2
Lethargy (see also Central nervous system depression in 'Neurological') 2
Limb weakness 2
Muscle shaking 2
Involuntary movement 2
Elevated blood urea nitrogen (BUN) 2

Outcome Breakdown

Ongoing
22 (57.9%)
Recovered/Normal
8 (21.1%)
Outcome Unknown
5 (13.2%)
Euthanized
2 (5.3%)
Died
1 (2.6%)

Heartguard Adverse Event Insights

38 reports name Heartguard; 3 recorded a death outcome (7.9% of reported events, not a population-level mortality rate). Active ingredient: Heartguard. Administration routes: Oral, Unknown.

By species: Dog (38 reports). By breed: Crossbred Canine/dog (8), Siberian Husky (4), Retriever - Labrador (4).

Leading clinical signs: Lack of efficacy (endoparasite) - heartworm (13), Seizure NOS (7), Vomiting (4), Ataxia (3). Outcome, 38 coded reports: Ongoing leads at 57.9%.

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.