Drug profile

The FDA adverse-event record for Sulfadimethoxine

774 FDA reports name Sulfadimethoxine, a high-volume drug in the CVM extract. Species, reactions, and outcomes follow.

#222 of 2,679
by report volume (all drugs)
774
adverse-event reports
10.6%
death-coded share
Dog
most-reported species

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Sulfadimethoxine ranks #222 of 2679 by total reports (774) and #522 of 1130 by death-coded share (10.6%). 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)
#222
This drug, reports of 2679
#522
This drug, death share of 1130

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. Sulfadimethoxine has 774 reports now versus 765 in that prior snapshot: 9 more (1.2%).

Report change
+9
Death-coded reports
+1
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 Sulfadimethoxine changes

Signature read: 774 reports place Sulfadimethoxine in the upper third of FDA AER volume (#222 of 2,679).

Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
774
Total Reports
82
Deaths Reported
10.6%
Death-coded share of reports

Active Ingredients

Sulfadimethoxine

Administration Routes

OralUnknownSubcutaneousTopicalIntramuscularIntravenousRectalOphthalmic

Species Affected

Dog 480
Unknown 132
Cat 124
Cattle 31
Human 3
Rabbit 3
Sheep 1

Most Affected Breeds

Unknown 135
Retriever - Labrador 57
Domestic Shorthair 56
Retriever - Golden 38
Dog (unknown) 26
Crossbred Canine/dog 23
Chihuahua 21
Shepherd Dog - German 20
Boxer (German Boxer) 17
Cat (other) 17

Most Reported Reactions

Vomiting 106
Lethargy (see also Central nervous system depression in 'Neurological') 96
Diarrhoea 93
Lack of efficacy (protozoa) - Coccidia 80
Death 53
Anorexia 50
Other abnormal test result NOS 42
Emesis 34
Fever 31
Anaemia NOS 31
Uncoded sign 31
Ataxia 29

Outcome Breakdown

Ongoing
210 (35.8%)
Outcome Unknown
147 (25.1%)
Recovered/Normal
139 (23.7%)
Died
64 (10.9%)
Euthanized
18 (3.1%)
Recovered with Sequela
8 (1.4%)

Sulfadimethoxine: high report volume in the FDA AER row

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.

High-volume nationwide drug peers

Two openFDA-derived peer sets for Sulfadimethoxine, both floored at ≥50 reports so the neighborhoods stay in the advertised mass.

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 Sulfadimethoxine (#222 of 2,679 by report volume); death-coded 10.6%. PlainBreed drug row · report volume stamp 774 · 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 →