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

The FDA has received 41 reports of loss of appetite in dogs after Fipronil + Pyriproxyfen + S-methoprene. That is 9.5% of all reports for this medicine, compared with 8.4% across reports for all dog medicines.

41Reports

44%Marked serious

49%Recovered

4.9%Died or euthanised

12 daysTypical onset

How soon it started

Same day

5 17%

1–2 days

4 14%

3–7 days

4 14%

1–4 weeks

12 41%

Over a month

4 14%

How the animals did

Recovered

20 49%

Still unwell when reported

2 4.9%

Died

1 2.4%

Euthanised

1 2.4%

Not known

17 41%

Problems reported at the same time

23 56%

22 54%

12 29%

3 7.3%

3 7.3%

Hypoalbuminaemia

3 7.3%

Liver problems

2 4.9%

Elevated lipase

2 4.9%

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 loss of appetite in dogs?: 41 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 12 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

Loss of appetite after Spinosad (Comfortis) 3,161 reports · 5.5% of its reports
Loss of appetite after Lufenuron + Milbemycin Oxime (Sentinel) 1,500 reports · 5.8% of its reports
Loss of appetite after Imidacloprid + Moxidectin (Advantage Multi) 1,137 reports · 8.7% of its reports
Loss of appetite after Nitenpyram (Capstar) 807 reports · 7.5% of its reports
Loss of appetite after Lufenuron + Milbemycin Oxime + Praziquantel (Sentinel Spectrum) 469 reports · 4.7% of its reports
Loss of appetite after Fipronil + S-methoprene (Frontline Plus) 230 reports · 7.8% of its reports
Loss of appetite after Flumethrin + Imidacloprid (Seresto) 172 reports · 7.6% of its reports
Loss of appetite after Imidacloprid 147 reports · 7.7% of its reports
Loss of appetite after Fipronil 123 reports · 8.7% of its reports
Loss of appetite after Lufenuron 126 reports · 12% of its reports

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