Behaviour change after Ilunocitinib (Zenrelia) in dogs

135 reports to the FDA describe behaviour change in dogs given Ilunocitinib. That is 6.1% of all reports for this medicine, compared with 2.5% across reports for all dog medicines, so it is reported unusually often with this medicine.

135Reports

29%Marked serious

21%Recovered

12%Died or euthanised

31 daysTypical onset

How soon it started

Same day

12 10%

1–2 days

9 7.5%

3–7 days

10 8.3%

1–4 weeks

28 23%

Over a month

61 51%

How the animals did

Recovered

28 21%

Still unwell when reported

48 36%

Died

6 4.4%

Euthanised

10 7.4%

Not known

43 32%

Problems reported at the same time

34 25%

31 23%

22 16%

16 12%

15 11%

15 11%

15 11%

Didn't work as expected

14 10%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

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

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

Questions owners ask

Can Ilunocitinib cause behaviour change in dogs?: 135 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 31 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).

Behaviour change with similar medicines

Behaviour change after Oclacitinib (Apoquel) 1,391 reports · 4.8% of its reports
Behaviour change after Cyclosporine (Atopica) 431 reports · 2.8% of its reports

All reported side effects of Ilunocitinib in dogs · Medicines most reported with behaviour change