Syncope after Furosemide in dogs

The FDA has received 34 reports of syncope in dogs after Furosemide. That is 2.2% of all reports for this medicine, compared with 0.1% across reports for all dog medicines, so it is reported unusually often with this medicine.

34Reports

94%Marked serious

15%Recovered

32%Died or euthanised

30 daysTypical onset

How soon it started

Same day

4 17%

1–2 days

0 0.0%

3–7 days

1 4.2%

1–4 weeks

8 33%

Over a month

11 46%

How the animals did

Recovered

5 15%

Still unwell when reported

5 15%

Died

7 21%

Euthanised

4 12%

Not known

13 38%

Problems reported at the same time

10 29%

10 29%

9 26%

6 18%

6 18%

6 18%

5 15%

5 15%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Type: medicine.

Questions owners ask

Can Furosemide cause syncope in dogs?: 34 reports link the two, but a report alone does not prove the medicine was the cause: other illnesses, other medicines or coincidence can be involved. Your vet can judge it for your animal.
How soon after a dose was it reported?: In half of the reports with dates, it started within 30 days of the first dose.
What should I do?: Don't give another dose until you've spoken to your vet, and keep the packaging so you can tell them the product and dose. Your vet can also report it to the FDA (or you can, through the manufacturer or FDA form 1932a).

Syncope with similar medicines

Syncope after Melarsomine (Immiticide) 43 reports · 0.2% of its reports
Syncope after Enalapril 25 reports · 1.5% of its reports

All reported side effects of Furosemide in dogs · Medicines most reported with syncope