Loss of appetite after Amitraz + Fipronil + S-methoprene in dogs

The FDA has received 31 reports of loss of appetite in dogs after Amitraz + Fipronil + S-methoprene. That is 6.7% of all reports for this medicine, compared with 8.4% across reports for all dog medicines.

31Reports
71%Marked serious
61%Recovered
6.5%Died or euthanised
30 daysTypical onset
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How soon it started

Same day
1 5.3%
1–2 days
2 11%
3–7 days
3 16%
1–4 weeks
5 26%
Over a month
8 42%

How the animals did

Recovered
19 61%
Still unwell when reported
3 9.7%
Euthanised
2 6.5%
Not known
7 23%

Problems reported at the same time

28 90%
Breathing problems
6 19%
Pemphigus foliaceus
4 13%
Liver problems
4 13%
Pale mucous membrane
3 9.7%

Age of the animals

Under 1 year
1
1–3 years
8
4–7 years
8
8–11 years
7
12+ years
7

About this medicine

Fipronil kills fleas and ticks (spot-on).

Questions owners ask

Can Amitraz + Fipronil + S-methoprene cause loss of appetite in dogs?
31 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 30 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 Amitraz + Fipronil + S-methoprene in dogs · Medicines most reported with loss of appetite