Low thyroxine (t4) after Maropitant (Cerenia) in dogs

52 reports to the FDA describe low thyroxine (t4) in dogs given Maropitant. That is 0.4% 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.

52Reports

96%Marked serious

1.9%Recovered

48%Died or euthanised

22 daysTypical onset

How soon it started

Same day

8 19%

1–2 days

4 9.3%

3–7 days

5 12%

1–4 weeks

6 14%

Over a month

20 47%

How the animals did

Recovered

1 1.9%

Still unwell when reported

19 37%

Died

8 15%

Euthanised

17 33%

Not known

7 13%

Problems reported at the same time

39 75%

32 62%

27 52%

26 50%

25 48%

24 46%

20 38%

18 35%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Maropitant prevents vomiting and motion sickness.

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

Questions owners ask

Can Maropitant cause low thyroxine (t4) in dogs?: 52 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 22 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 Maropitant in dogs · Medicines most reported with low thyroxine (t4)