Drug profile

The FDA adverse-event record for Diclazuril Oral Pellets

128 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Diclazuril Oral Pellets. See the species affected, top reactions, and outcomes below.

128
adverse-event reports
3.9%
death-coded share
Horse
most-reported species
29
Lack of efficacy (protozoa) - NOS - 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.
128
Total Reports
5
Deaths Reported
3.9%
Death Rate

Active Ingredients

Diclazuril Oral Pellets

Administration Routes

OralUnknown

Species Affected

Horse 65
Unknown 60
Other Equids 1
Other Mammals 1
Dog 1

Most Affected Breeds

Unknown 62
Quarter Horse 14
Horse (unknown) 9
Warmblood (unspecified) 9
Thoroughbred 7
Crossbred Equine/horse 3
Irish Hunter 2
Appaloosa 2
Warmblood - Dutch 2
Hanovarian 2

Most Reported Reactions

Lack of efficacy (protozoa) - NOS 29
Containers, Damaged 17
Closure, Abnormal 14
Underfilling, Container 13
Defect Unknown/Not Specified 10
Underfilling, Buckets/Pails 8
Containers, Abnormal 8
Uncoded sign 6
Drug administration duration too long 6
Death by euthanasia 5
Weight loss 5
Diarrhoea 4

Outcome Breakdown

Ongoing
54 (79.4%)
Recovered/Normal
7 (10.3%)
Euthanized
5 (7.4%)
Outcome Unknown
2 (2.9%)

Diclazuril Oral Pellets Adverse Event Insights

128 reports name Diclazuril Oral Pellets; 5 recorded a death outcome (3.9% of reported events, not a population-level mortality rate). Active ingredient: Diclazuril Oral Pellets. Administration routes: Oral, Unknown.

By species: Horse (65 reports), Unknown (60 reports), Other Equids (1 reports). By breed: Unknown (62), Quarter Horse (14), Horse (unknown) (9).

Leading clinical signs: Lack of efficacy (protozoa) - NOS (29), Containers, Damaged (17), Closure, Abnormal (14), Underfilling, Container (13). Outcome, 68 coded reports: Ongoing leads at 79.4%.

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.