Behaviour change after Amitraz + Fipronil + S-methoprene in dogs

32 reports to the FDA describe behaviour change in dogs given Amitraz + Fipronil + S-methoprene. That is 7.0% of all reports for this medicine, compared with 2.5% across reports for all dog medicines, so it is reported unusually often with this medicine.

32Reports

66%Marked serious

75%Recovered

0.0%Died or euthanised

61 daysTypical onset

How soon it started

Same day

3 14%

1–2 days

1 4.8%

3–7 days

1 4.8%

1–4 weeks

0 0.0%

Over a month

16 76%

How the animals did

Recovered

24 75%

Still unwell when reported

1 3.1%

Not known

7 22%

Problems reported at the same time

Lethargy

16 50%

Restlessness or agitation

7 22%

Vomiting

6 19%

Application site reaction

4 13%

Anxiety

4 13%

Itching

4 13%

Loss of appetite

3 9.4%

Diarrhea

2 6.3%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Fipronil kills fleas and ticks (spot-on).

Questions owners ask

Can Amitraz + Fipronil + S-methoprene cause behaviour change in dogs?: 32 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 61 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).

Behaviour change with similar medicines

Behaviour change after Spinosad (Comfortis) 1,176 reports · 2.1% of its reports
Behaviour change after Lufenuron + Milbemycin Oxime (Sentinel) 358 reports · 1.4% of its reports
Behaviour change after Imidacloprid + Moxidectin (Advantage Multi) 1,205 reports · 9.2% of its reports
Behaviour change after Nitenpyram (Capstar) 323 reports · 3.0% of its reports
Behaviour change after Lufenuron + Milbemycin Oxime + Praziquantel (Sentinel Spectrum) 128 reports · 1.3% of its reports
Behaviour change after Fipronil + S-methoprene (Frontline Plus) 181 reports · 6.1% of its reports
Behaviour change after Flumethrin + Imidacloprid (Seresto) 167 reports · 7.3% of its reports
Behaviour change after Imidacloprid 94 reports · 4.9% of its reports
Behaviour change after Fipronil 66 reports · 4.7% of its reports
Behaviour change after Lufenuron 20 reports · 2.0% of its reports

All reported side effects of Amitraz + Fipronil + S-methoprene in dogs · Medicines most reported with behaviour change