Monocytosis after Maropitant (Cerenia) in dogs

The FDA has received 327 reports of monocytosis in dogs after Maropitant. That is 2.8% 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.

327Reports

84%Marked serious

6.4%Recovered

41%Died or euthanised

4 daysTypical onset

How soon it started

Same day

51 19%

1–2 days

64 23%

3–7 days

46 17%

1–4 weeks

50 18%

Over a month

64 23%

How the animals did

Recovered

20 6.1%

Recovered with lasting effects

1 0.3%

Still unwell when reported

116 35%

Died

49 15%

Euthanised

85 26%

Not known

56 17%

Problems reported at the same time

225 69%

214 65%

190 58%

188 57%

182 56%

136 42%

136 42%

134 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 monocytosis in dogs?: 327 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 4 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).

Monocytosis with similar medicines

Monocytosis after Capromorelin (Entyce) 53 reports · 3.5% of its reports

All reported side effects of Maropitant in dogs · Medicines most reported with monocytosis