Lethargy after Ilunocitinib (Zenrelia) in dogs

309 reports to the FDA describe lethargy in dogs given Ilunocitinib. That is 14% of all reports for this medicine, compared with 11% across reports for all dog medicines.

309Reports

43%Marked serious

24%Recovered

18%Died or euthanised

40 daysTypical onset

How soon it started

Same day

30 11%

1–2 days

19 7.3%

3–7 days

25 9.6%

1–4 weeks

40 15%

Over a month

147 56%

How the animals did

Recovered

74 24%

Still unwell when reported

103 33%

Died

16 5.2%

Euthanised

40 13%

Not known

76 25%

Problems reported at the same time

130 42%

99 32%

78 25%

70 23%

60 19%

55 18%

51 17%

48 16%

Age of the animals

Under 1 year

1–3 years

4–7 years

125

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 lethargy in dogs?: 309 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 40 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).

Lethargy with similar medicines

Lethargy after Oclacitinib (Apoquel) 3,089 reports · 11% of its reports
Lethargy after Cyclosporine (Atopica) 2,122 reports · 14% of its reports

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