Drug profile

The FDA adverse-event record for Sulfadiazine + Trimethoprim

32 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Sulfadiazine + Trimethoprim. See the species affected, top reactions, and outcomes below.

32
adverse-event reports
6.3%
death-coded share
Unknown
most-reported species
5
Appearance, Abnormal - 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.
32
Total Reports
2
Deaths Reported
6.3%
Death Rate

Active Ingredients

SulfadiazineTrimethoprim

Administration Routes

UnknownOralIntramuscular

Species Affected

Unknown 20
Horse 11
Donkey 1

Most Affected Breeds

Unknown 26
Quarter Horse 3
Horse (unknown) 2
Pony (unspecified) 1

Most Reported Reactions

Appearance, Abnormal 5
Containers, Leaking 4
Injection site swelling 3
Seal, Abnormal 3
Caps, Abnormal 2
Colic 2
Underfilling, Package 2
Pruritus 1
Irritability 1
Welt 1
Self trauma 1
Tendon injury 1

Outcome Breakdown

Recovered/Normal
5 (41.7%)
Outcome Unknown
3 (25.0%)
Recovered with Sequela
2 (16.7%)
Died
1 (8.3%)
Euthanized
1 (8.3%)

Sulfadiazine + Trimethoprim Adverse Event Insights

32 reports name Sulfadiazine + Trimethoprim; 2 recorded a death outcome (6.3% of reported events, not a population-level mortality rate). Active ingredients: Sulfadiazine, Trimethoprim. Administration routes: Unknown, Oral, Intramuscular.

By species: Unknown (20 reports), Horse (11 reports), Donkey (1 reports). By breed: Unknown (26), Quarter Horse (3), Horse (unknown) (2).

Leading clinical signs: Appearance, Abnormal (5), Containers, Leaking (4), Injection site swelling (3), Seal, Abnormal (3). Outcome, 12 coded reports: Recovered/Normal leads at 41.7%.

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.