Splenomegaly after Maropitant (Cerenia) in dogs

The FDA has received 76 reports of splenomegaly in dogs after Maropitant. That is 0.6% 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.

76Reports

88%Marked serious

3.9%Recovered

51%Died or euthanised

11 daysTypical onset

How soon it started

Same day

14 23%

1–2 days

4 6.5%

3–7 days

11 18%

1–4 weeks

15 24%

Over a month

18 29%

How the animals did

Recovered

2 2.6%

Recovered with lasting effects

1 1.3%

Still unwell when reported

24 32%

Died

17 22%

Euthanised

22 29%

Not known

10 13%

Problems reported at the same time

57 75%

52 68%

45 59%

39 51%

39 51%

38 50%

Abnormal ultrasound finding

32 42%

Abnormal radiograph finding

31 41%

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 splenomegaly in dogs?: 76 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 11 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 splenomegaly