Loss of appetite after Flumethrin + Imidacloprid (Seresto) in cats

The FDA has received 58 reports of loss of appetite in cats after Flumethrin + Imidacloprid. That is 8.6% of all reports for this medicine, compared with 14% across reports for all cat medicines, so it is reported less often than average with this medicine.

58Reports
72%Marked serious
34%Recovered
16%Died or euthanised
10 daysTypical onset
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How soon it started

Same day
8 16%
1–2 days
6 12%
3–7 days
9 18%
1–4 weeks
15 30%
Over a month
12 24%

How the animals did

Recovered
20 34%
Still unwell when reported
10 17%
Died
4 6.9%
Euthanised
5 8.6%
Not known
19 33%

Problems reported at the same time

Age of the animals

Under 1 year
6
1–3 years
15
4–7 years
13
8–11 years
10
12+ years
12

About this medicine

Imidacloprid kills fleas (spot-on or collar).

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

Questions owners ask

Can Flumethrin + Imidacloprid cause loss of appetite in cats?
58 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 10 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).

Loss of appetite with similar medicines

All reported side effects of Flumethrin + Imidacloprid in cats · Medicines most reported with loss of appetite