Digestive tract disorder after Fipronil + S-methoprene (Frontline Plus) in dogs

27 reports to the FDA describe digestive tract disorder in dogs given Fipronil + S-methoprene. That is 0.9% of all reports for this medicine, compared with 2.0% across reports for all dog medicines, so it is reported less often than average with this medicine.

27Reports

70%Marked serious

33%Recovered

3.7%Died or euthanised

22 daysTypical onset

How soon it started

Same day

3 25%

1–2 days

3 25%

3–7 days

0 0.0%

1–4 weeks

1 8.3%

Over a month

5 42%

How the animals did

Recovered

9 33%

Still unwell when reported

4 15%

Euthanised

1 3.7%

Not known

13 48%

Problems reported at the same time

Diarrhea

11 41%

Vomiting

10 37%

Didn't work as expected

8 30%

6 22%

5 19%

5 19%

2 7.4%

2 7.4%

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).

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

Questions owners ask

Can Fipronil + S-methoprene cause digestive tract disorder in dogs?: 27 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 22 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).

Digestive tract disorder with similar medicines

Digestive tract disorder after Spinosad (Comfortis) 141 reports · 0.2% of its reports
Digestive tract disorder after Lufenuron + Milbemycin Oxime (Sentinel) 108 reports · 0.4% of its reports
Digestive tract disorder after Imidacloprid + Moxidectin (Advantage Multi) 46 reports · 0.4% of its reports
Digestive tract disorder after Nitenpyram (Capstar) 30 reports · 0.3% of its reports
Digestive tract disorder after Lufenuron + Milbemycin Oxime + Praziquantel (Sentinel Spectrum) 33 reports · 0.3% of its reports

All reported side effects of Fipronil + S-methoprene in dogs · Medicines most reported with digestive tract disorder