Tarry or black stool after Trilostane (Vetoryl) in dogs

The FDA has received 32 reports of tarry or black stool in dogs after Trilostane. That is 0.3% 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.

32Reports

84%Marked serious

9.4%Recovered

47%Died or euthanised

13 daysTypical onset

How soon it started

Same day

2 9.1%

1–2 days

2 9.1%

3–7 days

6 27%

1–4 weeks

2 9.1%

Over a month

10 45%

How the animals did

Recovered

3 9.4%

Still unwell when reported

4 13%

Died

7 22%

Euthanised

8 25%

Not known

10 31%

Problems reported at the same time

18 56%

15 47%

15 47%

13 41%

13 41%

9 28%

8 25%

6 19%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Trilostane treats Cushing's disease (an overactive adrenal gland).

Products with this ingredient include Vetoryl. The FDA hides brand names in its public data, so these reports cover every product with the same active ingredients.

Questions owners ask

Can Trilostane cause tarry or black stool in dogs?: 32 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 13 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).

All reported side effects of Trilostane in dogs · Medicines most reported with tarry or black stool