Pet Drug Reports

Ingredients

Active ingredient · pooled across combinations

Sulfadiazine: adverse event reports, pooled

5 ingredient sets in reports · 12 FDA-approved applications in the Green Book

333reports naming the ingredient, 1987–20260% of all reports · about 9 a year
13reports, 12 months to March 202610 in the 12 months before
56.8%classed serious, as reportedall reports: 38.6%
35.7%of reports concern horsesdog 33.3%

333 adverse event reports received by FDA list a drug containing sulfadiazine, alone or in combination, from March 1987 to March 2026. This page pools every ingredient set that includes it; 5 such sets appear in reports.

The Green Book lists 12 FDA-approved applications containing it. openFDA masks brand and manufacturer names in adverse event records, so the reports counted here cannot be attributed to a particular brand.

13 reports arrived in the 12 months to March 2026, up 30% from 10 in the 12 months before. FDA posts reports quarterly with a delay of three to six months, so the newest months are incomplete and usually grow in later releases. That is about 9 reports a year over its reporting history and 0% of all reports.

Pooled across every set, the terms listed most often are death (16.2%), diarrhoea (9.3%) and anorexia (7.8%). Many drugs combine several ingredients, and many reports list several drugs, so a term on this page may relate to any of them or to none.

Of reports that state seriousness, 56.8% were classed as serious (38.6% across the whole database); 21.9% record a death or euthanasia (6.4% overall). Ingredients used in older or sicker animals, or in anaesthesia and cancer care, carry higher shares for that reason alone.

Ingredient sets that include sulfadiazine

Active ingredients recorded for the drugReportsShare of this page's reportsLatest 12 months
Sulfadiazine + Trimethoprim28685.9%6
Pyrimethamine + Sulfadiazine278.1%0
Enrofloxacin + Sulfadiazine144.2%6
Sulfadiazine51.5%0
Gentamicin + Sulfadiazine + Vitamin A10.3%1

Ordered by report count. FDA states that these data "cannot be used to estimate the risk associated with the product or compare one drug or device product with another"; counts follow sales volume and years on the market. A report can list more than one set, so shares can add to more than 100%.

Signs listed in reports, pooled

share of sulfadiazine reports listing the termall reports in the database

  1. Death16.2%54
  2. Diarrhoea[diarrhea]9.3%31
  3. Anorexia[not eating]7.8%26
  4. Depression[dull, quiet or withdrawn]7.8%26
  5. Collapse7.2%24
  6. Vomiting6.3%21
  7. Fever5.4%18
  8. Lethargy[unusually tired or inactive]5.4%18
  9. Death by euthanasia[the animal was euthanized]5.1%17
  10. Thrombocytopenia[low platelet count]4.8%16
  11. Anaemia NOS[low red blood cell count]4.5%15
  12. Anaphylaxis[sudden severe allergic-type reaction]4.5%15
  13. Convulsion[seizure]4.5%15
  14. Elevated alanine aminotransferase (ALT)[a liver enzyme above the normal range]4.2%14
  15. Pruritus[itching]3.6%12
  16. Accidental exposure[exposure that was not intended]2.7%9
  17. Containers, Abnormal[a product quality report, not a sign in an animal]2.7%9
  18. Other abnormal test result NOS[abnormal laboratory result, type not specified]2.7%9
  19. Seal, Abnormal[a product quality report, not a sign in an animal]2.7%9
  20. Ataxia[unsteady, uncoordinated movement]2.4%8
  21. Behavioural disorder NOS[behaviour change, type not specified]2.4%8
  22. Dyspnoea[difficulty breathing]2.4%8
  23. Elevated blood urea nitrogen (BUN)[a kidney value above the normal range]2.4%8
  24. Epistaxis[nosebleed]2.4%8
  25. Leucocytosis NOS[high white blood cell count]2.4%8
  26. Color, Abnormal[a product quality report, not a sign in an animal]2.1%7
  27. Elevated serum alkaline phosphatase (SAP)[a liver and bone enzyme above the normal range]2.1%7

Pooled across every ingredient set and every report that names the ingredient. One report can list several terms and several drugs; a term here may relate to any of them or to none.

Monthly reports by species, five years

Dog15 · peak 3
Dec 2023: 1Jan 2024: 1Jun 2024: 1Aug 2024: 1Sep 2024: 1Dec 2024: 2Mar 2025: 1Jul 2025: 3Nov 2025: 1Dec 2025: 1Jan 2026: 1Mar 2026: 12022202320242025
Cat3 · peak 1
Sep 2022: 1Jan 2025: 1Dec 2025: 12022202320242025
Horse9 · peak 2
Jul 2022: 1Oct 2022: 1Mar 2023: 1Aug 2023: 1Oct 2023: 1Aug 2025: 1Oct 2025: 1Nov 2025: 22022202320242025
Other8 · peak 1
May 2021: 1Sep 2021: 1Dec 2022: 1Jun 2023: 1Apr 2024: 1Oct 2024: 1Nov 2024: 1Jul 2025: 12022202320242025

By month of receipt; each panel has its own scale. The newest months are incomplete because FDA posts reports with a delay of three to six months.

016311987: 419871988: 61989: 21990: 121991: 3119911992: 81993: 41994: 61995: 1019951996: 41997: 91998: 41999: 1219992000: 242001: 142002: 52003: 1020032004: 62005: 32006: 112007: 620072008: 52009: 112010: 42011: 420112012: 52013: 112014: 182015: 620152016: 122017: 102018: 102019: 520192020: 62021: 22022: 42023: 520232024: 92025: 132026: 2

Outcomes, report types and ages

Outcome recorded in the report

Recovered/Normal7.2%24
Recovered with Sequela0.9%3
Ongoing5.7%19
Died19.5%65
Euthanized2.4%8
Outcome Unknown8.4%28

What kind of report it was

Safety issue75.4%251
Lack of expected effectiveness1.5%5
Both safety and lack of expected effectiveness1.8%6
Manufacturing or product defect21.3%71
Other0%0

Species

Horse35.7%119
Dog33.3%111
Cat4.5%15
Human exposure1.8%6
Cattle1.2%4
Fish0.6%2

Age of the animal

Under 1 year6.3%21
1 to 3 years18%60
4 to 7 years14.4%48
8 to 11 years14.1%47
12 years and over15%50
Age not given32.1%107

Coloured bar: reports naming sulfadiazine. Grey bar: all 1,357,245 reports. Outcomes are as stated by the reporter; FDA has not necessarily determined whether any product played a part.

In context

MeasureSulfadiazineAll reports
Reports3331,357,245
Latest 12 months against the 12 before+30%-5%
Classed serious, of reports stating it56.8%38.6%
Death or euthanasia recorded, per 1,000 reports219.263.8
Filed as lack of expected effectiveness (wholly or partly)3.3%23%

Shares of reports, not of animals treated: how many animals receive the ingredient is not public. Ingredients used in anaesthesia, cancer care or in old animals carry more serious outcomes in their reports for that reason alone.

FDA-approved products containing sulfadiazine (Green Book)

Reference information, not report statistics. openFDA masks brand and manufacturer names in adverse event records, so the reports counted here cannot be attributed to a particular brand. The list below is the FDA Green Book as of 1 Oct 2026; nothing on this page says which of these products, if any, a report concerned.

Trade nameActive ingredientsSponsorApproved forApplication
Tribrissen 120 Tablets; Tribrissen 30 Tablets; Tribrissen 480 Tablets; Tribrissen 960 TabletsSulfadiazine, TrimethoprimIntervet, Inc.DogsNADA 095-614
Tribrissen 48% InjectionSulfadiazine, TrimethoprimIntervet, Inc.HorsesNADA 106-965
Di-Trim TabletsSulfadiazine, TrimethoprimZoetis Inc.DogsNADA 115-578
Tribrissen 400 Oral PasteSulfadiazine, TrimethoprimIntervet, Inc.HorsesNADA 131-918
Di-Trim 24%Sulfadiazine, TrimethoprimZoetis Inc.DogsNADA 132-486
Di-Trim 48% InjectionSulfadiazine, TrimethoprimZoetis Inc.HorsesNADA 134-778
Di-Trim 400 PasteSulfadiazine, TrimethoprimZoetis Inc.HorsesNADA 136-342
Tribrissen 60 Oral SuspensionSulfadiazine, TrimethoprimIntervet, Inc.DogsNADA 136-741
EQUISUL-SDTSulfadiazine, TrimethoprimAurora Pharmaceutical, Inc.HorsesNADA 141-360
Uniprim PowderSulfadiazine, TrimethoprimNeogen Corp.HorsesANADA 200-033
Tucoprim PowderSulfadiazine, TrimethoprimZoetis Inc.HorsesANADA 200-244
Tylocine Sulfa Tablets 50approval voluntarily withdrawnSulfadiazine, Sulfamerazine, Sulfamethazine, TylosinElanco Animal Health, A Division of Eli Lilly & Co.—NADA 030-330

Species are the major species the Green Book search lists for the application ("—" where it lists another species or none). Approval dates are not part of the Green Book listing files and are not shown. Pioneer applications (NADA) come first, then generics (ANADA).

Questions about sulfadiazine reports

How many FDA adverse event reports mention sulfadiazine?

333 reports through March 2026, 13 of them in the latest 12 months, counting sulfadiazine alone and in combinations.

Which brands do these reports concern?

That cannot be known from the public data. openFDA masks brand and manufacturer names in adverse event records, so the reports counted here cannot be attributed to a particular brand. The Green Book reference list on this page names approved products containing sulfadiazine without any counts.

In which combinations is sulfadiazine reported?

Sulfadiazine + Trimethoprim (85.9% of these reports), Pyrimethamine + Sulfadiazine (8.1% of these reports), Enrofloxacin + Sulfadiazine (4.2% of these reports), Sulfadiazine (1.5% of these reports) and Gentamicin + Sulfadiazine + Vitamin A (0.3% of these reports).

What reactions are reported for sulfadiazine?

death (16.2%), diarrhoea (9.3%), anorexia (7.8%), depression (7.8%) and collapse (7.2%). Shares are of reports naming the ingredient; one report can list several terms.

Which animals are these reports about?

horse (35.7%), dog (33.3%) and cat (4.5%).

Does a high count mean sulfadiazine is a problem ingredient?

A count cannot show that. FDA states that "there is no certainty that the reported drug or device caused the adverse event" and that the event "may have been related to an underlying disease, other drugs used at the same time or other non-drug related sources." Widely used ingredients collect more reports because more animals receive them.

How do I report a problem?

Call the drug company using the number on the label, or send Form FDA 1932a to FDA. See the guide on how to report.

Where this comes from. Counts are built from the openFDA Animal & Veterinary adverse event bulk files released 28 Sep 2026, which hold reports FDA's Center for Veterinary Medicine received through 31 Mar 2026. openFDA masks brand and manufacturer names in these files, so drugs are counted by the active ingredients each record discloses and no figure is attributed to a brand, application or company. Ingredient names, and the separate reference lists of approved products, follow the FDA Green Book as of 1 Oct 2026. Ingredient names follow the Green Book; salts and forms are kept as FDA lists them. Drug entries are matched by the active ingredients their unmasked ingredient field discloses. No report text, lot numbers or reporter details are published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.