Mast cell tumour after Oclacitinib (Apoquel) in dogs

202 reports to the FDA describe mast cell tumour in dogs given Oclacitinib. That is 0.7% of all reports for this medicine, compared with 0.0% across reports for all dog medicines, so it is reported unusually often with this medicine.

202Reports

98%Marked serious

15%Recovered

6.9%Died or euthanised

105 daysTypical onset

How soon it started

Same day

18 19%

1–2 days

2 2.2%

3–7 days

0 0.0%

1–4 weeks

13 14%

Over a month

60 65%

How the animals did

Recovered

30 15%

Still unwell when reported

133 66%

Died

11 5.4%

Euthanised

3 1.5%

Not known

25 12%

Problems reported at the same time

Dermal mass

25 12%

Didn't work as expected

18 8.9%

14 6.9%

13 6.4%

12 5.9%

9 4.5%

8 4.0%

8 4.0%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Oclacitinib controls itching from allergies (tablet, a JAK inhibitor).

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

Questions owners ask

Can Oclacitinib cause mast cell tumour in dogs?: 202 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 105 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 Oclacitinib in dogs · Medicines most reported with mast cell tumour