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. Species, reactions, and outcomes follow.

#1407 of 2,679
by report volume (all drugs)
32
adverse-event reports
6.3%
death-coded share
Unknown
most-reported species
Verify with FDA CVM →

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Sulfadiazine + Trimethoprim ranks #1387 of 2679 by total reports (32). Death-coded-share rank requires at least 50 reports. National dual: Milbemycin Oxime + Spinosad is #1 of 2679 drugs by total adverse-event reports (149,624) at death-coded-share rank 965 of 1130 drugs with at least 50 reports (2.3%); separately, Atlantic Salmon Transgenic Whole (Opafp-Ghc2 Rdna Construct Inserted Into The A-Locus In The Eo-1A Lineage) is #1 highest death-coded share at 97.8% (report rank #821).

149,624
Milbemycin Oxime + Spinosad reports (#1)
97.8%
Atlantic Salmon Transgenic Whole (Opafp-Ghc2 Rdna Construct Inserted Into The A-Locus In The Eo-1A Lineage) death share (#1)
#1387
This drug, reports of 2679

Report volume reflects how common a breed or drug is and how often owners and vets file — not actual risk. Death-coded share ranks are limited to entries with enough reports to be meaningful. The two maps do not agree at #1.

Release-over-release change

What changed in the latest FDA data snapshot

PlainBreed reconstructed the prior snapshot from dated openFDA partitions through 2025 Q4, then compared it with the 2026-07-27 openFDA export. Sulfadiazine + Trimethoprim has 32 reports now versus 32 in that prior snapshot: 0 the same number of (0.0%).

Report change
+0
Death-coded reports
+0
Death-coded share
+0.0 pts

This compares reported-event counts in two source snapshots. It does not establish a change in real-world risk, product safety, or disease incidence.

Subscribe to Sulfadiazine + Trimethoprim changes

Signature read: death-coded share at 6.3% is the most distinctive stamp on Sulfadiazine + Trimethoprim's FDA AER row.

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-coded share of reports

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

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.

What to do with this drug

A report does not prove a drug caused the reaction; consult a veterinarian before acting on this data.

Source: FDA Center for Veterinary Medicine openFDA Animal & Veterinary Adverse Events (CVM AER) · 2025

openFDA Animal & Veterinary Adverse Events (FDA CVM) for Sulfadiazine + Trimethoprim (#1407 of 2,679 by report volume); death-coded 6.3%. PlainBreed drug row · death-coded share stamp 6.3% · vintage 2025.

Informational only. FDA adverse-event reports are voluntary and do not prove causation; consult a veterinarian before acting on them. Verify with FDA CVM →