Drug profile

The FDA adverse-event record for Milbemycin Oxime + Praziquantel

34,806 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Milbemycin Oxime + Praziquantel. See the species affected, top reactions, and outcomes below.

34,806
adverse-event reports
2.5%
death-coded share
Dog
most-reported species
9,737
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.
34,806
Total Reports
882
Deaths Reported
2.5%
Death Rate

Active Ingredients

Milbemycin OximeMilbemycin Oxime + PraziquantelPraziquantel

Administration Routes

OralUnknownTopicalOtherCutaneousRectalSubcutaneousIntraocularOphthalmicIntracardiac

Species Affected

Dog 32,702
Unknown 2,072
Cat 15
Human 14
Other 2
Other Canids 1

Most Affected Breeds

Retriever - Labrador 5,387
Unknown 2,116
Retriever - Golden 1,961
Shepherd Dog - German 1,894
Crossbred Canine/dog 1,694
Dog (unknown) 1,407
Pit Bull 1,187
Shepherd Dog - Australian 1,075
Beagle 943
Chihuahua 734

Most Reported Reactions

Lack of efficacy (endoparasite) - heartworm 9,737
Vomiting 6,439
Diarrhoea 2,410
INEFFECTIVE, HOOKS 2,404
Lack of efficacy (endoparasite) - hookworm 2,336
Lethargy (see also Central nervous system depression in 'Neurological') 1,799
Other abnormal test result NOS 1,741
UNPALATABLE 1,727
Lack of efficacy (roundworm) 1,286
Lack of efficacy (endoparasite) - roundworm NOS 1,141
Seizure NOS 796
Not eating 731

Outcome Breakdown

Outcome Unknown
21,114 (64.5%)
Recovered/Normal
6,982 (21.3%)
Ongoing
3,695 (11.3%)
Died
556 (1.7%)
Euthanized
327 (1.0%)
Recovered with Sequela
69 (0.2%)

Milbemycin Oxime + Praziquantel Adverse Event Insights

34,806 reports name Milbemycin Oxime + Praziquantel; 882 recorded a death outcome (2.5% of reported events, not a population-level mortality rate). Active ingredients: Milbemycin Oxime, Milbemycin Oxime + Praziquantel, Praziquantel. Administration routes: Oral, Unknown, Topical, Other.

By species: Dog (32,702 reports), Unknown (2,072 reports), Cat (15 reports). By breed: Retriever - Labrador (5,387), Unknown (2,116), Retriever - Golden (1,961).

Leading clinical signs: Lack of efficacy (endoparasite) - heartworm (9,737), Vomiting (6,439), Diarrhoea (2,410), INEFFECTIVE, HOOKS (2,404). Outcome, 32,743 coded reports: Outcome Unknown leads at 64.5%.

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.