Lymphopenia after Oclacitinib (Apoquel) in dogs

The FDA has received 439 reports of lymphopenia in dogs after Oclacitinib. That is 1.5% of all reports for this medicine, compared with 0.3% across reports for all dog medicines, so it is reported unusually often with this medicine.

439Reports

36%Marked serious

5.7%Recovered

7.3%Died or euthanised

69 daysTypical onset

How soon it started

Same day

24 9.9%

1–2 days

10 4.1%

3–7 days

11 4.5%

1–4 weeks

46 19%

Over a month

151 62%

How the animals did

Recovered

24 5.5%

Recovered with lasting effects

1 0.2%

Still unwell when reported

344 78%

Died

7 1.6%

Euthanised

25 5.7%

Not known

38 8.7%

Problems reported at the same time

196 45%

183 42%

107 24%

87 20%

84 19%

82 19%

65 15%

Didn't work as expected

63 14%

Age of the animals

Under 1 year

1–3 years

4–7 years

178

8–11 years

185

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 lymphopenia in dogs?: 439 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 69 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).

Lymphopenia with similar medicines

Lymphopenia after Cyclosporine (Atopica) 83 reports · 0.5% of its reports
Lymphopenia after Ilunocitinib (Zenrelia) 149 reports · 6.8% of its reports

All reported side effects of Oclacitinib in dogs · Medicines most reported with lymphopenia