Drug profile

The FDA adverse-event record for Selamectin

30,845 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Selamectin. See the species affected, top reactions, and outcomes below.

30,845
adverse-event reports
3.3%
death-coded share
Cat
most-reported species
3,249
Lack of efficacy (ectoparasite) - flea - 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.
30,845
Total Reports
1,015
Deaths Reported
3.3%
Death Rate

Active Ingredients

Selamectin

Administration Routes

TopicalUnknownOralSubcutaneousOtherOphthalmicRespiratory (Inhalation)Auricular (Otic)IntraocularCutaneous

Species Affected

Cat 13,878
Dog 12,399
Unknown 3,730
Human 709
Rabbit 66
Guinea Pig 17
Ferret 17
Other Rodents 5
Other 4
Hamster 3

Most Affected Breeds

Domestic Shorthair 6,642
Unknown 4,527
Domestic (unspecified) 1,991
Retriever - Labrador 1,206
Cat (other) 1,097
Cat (unknown) 991
Crossbred Canine/dog 934
Domestic Longhair 846
Dog (unknown) 819
Chihuahua 652

Most Reported Reactions

Lack of efficacy (ectoparasite) - flea 3,249
Application site alopecia 3,082
Vomiting 2,511
INEFFECTIVE, HEARTWORM LARVAE 2,298
Lethargy (see also Central nervous system depression in 'Neurological') 2,293
Application site hair loss 2,240
Underfilling, Tubes 1,919
Anorexia 1,478
Diarrhoea 1,248
Lack of efficacy - NOS 1,047
Behavioural disorder NOS 945
Lack of efficacy (endoparasite) - hookworm 927

Outcome Breakdown

Outcome Unknown
9,008 (40.9%)
Ongoing
8,827 (40.1%)
Recovered/Normal
3,136 (14.2%)
Died
753 (3.4%)
Euthanized
264 (1.2%)
Recovered with Sequela
23 (0.1%)

Selamectin Adverse Event Insights

30,845 reports name Selamectin; 1,015 recorded a death outcome (3.3% of reported events, not a population-level mortality rate). Active ingredient: Selamectin. Administration routes: Topical, Unknown, Oral, Subcutaneous.

By species: Cat (13,878 reports), Dog (12,399 reports), Unknown (3,730 reports). By breed: Domestic Shorthair (6,642), Unknown (4,527), Domestic (unspecified) (1,991).

Leading clinical signs: Lack of efficacy (ectoparasite) - flea (3,249), Application site alopecia (3,082), Vomiting (2,511), INEFFECTIVE, HEARTWORM LARVAE (2,298). Outcome, 22,011 coded reports: Outcome Unknown leads at 40.9%.

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.