Seizures after Fipronil + Pyriproxyfen + S-methoprene in dogs

The FDA has received 43 reports of seizures in dogs after Fipronil + Pyriproxyfen + S-methoprene. That is 10.0% of all reports for this medicine, compared with 4.4% across reports for all dog medicines, so it is reported unusually often with this medicine.

43Reports

72%Marked serious

51%Recovered

4.7%Died or euthanised

1 daysTypical onset

How soon it started

Same day

10 32%

1–2 days

10 32%

3–7 days

1 3.2%

1–4 weeks

4 13%

Over a month

6 19%

How the animals did

Recovered

22 51%

Still unwell when reported

1 2.3%

Euthanised

2 4.7%

Not known

18 42%

Problems reported at the same time

Tremors

11 26%

Vomiting

7 16%

Lethargy

5 12%

Weakness

4 9.3%

Vocalising

3 7.0%

Behaviour change

3 7.0%

Stiffness

3 7.0%

Drooling

3 7.0%

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 Fipronil + Pyriproxyfen + S-methoprene cause seizures in dogs?: 43 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 1 day 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).

Seizures with similar medicines

Seizures after Spinosad (Comfortis) 2,116 reports · 3.7% of its reports
Seizures after Lufenuron + Milbemycin Oxime (Sentinel) 937 reports · 3.6% of its reports
Seizures after Imidacloprid + Moxidectin (Advantage Multi) 520 reports · 4.0% of its reports
Seizures after Nitenpyram (Capstar) 331 reports · 3.1% of its reports
Seizures after Lufenuron + Milbemycin Oxime + Praziquantel (Sentinel Spectrum) 279 reports · 2.8% of its reports
Seizures after Fipronil + S-methoprene (Frontline Plus) 214 reports · 7.2% of its reports
Seizures after Flumethrin + Imidacloprid (Seresto) 123 reports · 5.4% of its reports
Seizures after Imidacloprid 43 reports · 2.3% of its reports
Seizures after Fipronil 72 reports · 5.1% of its reports
Seizures after Lufenuron 65 reports · 6.4% of its reports

All reported side effects of Fipronil + Pyriproxyfen + S-methoprene in dogs · Medicines most reported with seizures