Sulfamethoxazole Trimethoprim side effects in dogs

60 reports sent to the FDA between 1998 and 2026 involve Sulfamethoxazole Trimethoprim in dogs. The most reported problems were lethargy, loss of appetite, blood problems. 30% were marked serious.

60Reports
30%Marked serious
37%Only medicine involved
20%Recovered
15%Died or euthanised
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About this medicine

Type: medicine.

Most reported side effects

Lethargy
18 30%
Loss of appetite
16 27%
Blood problems
13 22%
Vomiting
12 20%
Liver problems
7 12%
Swelling
5 8.3%
Diarrhea
5 8.3%
Keratoconjunctivitis sicca
4 6.7%
Lameness
4 6.7%
Haematuria
4 6.7%
Fever
4 6.7%
Itching
4 6.7%
Breathing problems
4 6.7%
Neutrophilia
3 5.0%
Kidney problems
3 5.0%

Share = percentage of this medicine's reports that mention the problem. One report can list several problems.

Reports that it didn't work

Some reports are about the medicine not working (for example a dog still getting fleas or heartworm), not about a side effect.

Didn't work as expected
8 13%
Didn't stop worms
2 3.3%

How soon problems started

Same day
6 18%
1–2 days
2 5.9%
3–7 days
5 15%
1–4 weeks
11 32%
Over a month
10 29%

Time from the first dose to the first sign, where both dates were reported (34 reports).

How the animals did

Recovered
10 17%
Recovered with lasting effects
2 3.3%
Still unwell when reported
16 27%
Died
8 13%
Euthanised
1 1.7%
Not known
23 38%

Breeds named most often

Popular breeds appear more often because there are more of them.

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