Dehydration after Fipronil + S-methoprene (Frontline Plus) in dogs

24 reports to the FDA describe dehydration in dogs given Fipronil + S-methoprene. That is 0.8% of all reports for this medicine, compared with 0.7% across reports for all dog medicines.

24Reports

79%Marked serious

21%Recovered

17%Died or euthanised

–Typical onset

How the animals did

Recovered

5 21%

Still unwell when reported

6 25%

Euthanised

4 17%

Not known

9 38%

Problems reported at the same time

13 54%

12 50%

11 46%

10 42%

8 33%

5 21%

5 21%

4 17%

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 dehydration in dogs?: 24 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.
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).

Dehydration with similar medicines

Dehydration after Spinosad (Comfortis) 281 reports · 0.5% of its reports
Dehydration after Lufenuron + Milbemycin Oxime (Sentinel) 127 reports · 0.5% of its reports
Dehydration after Imidacloprid + Moxidectin (Advantage Multi) 63 reports · 0.5% of its reports
Dehydration after Nitenpyram (Capstar) 42 reports · 0.4% of its reports
Dehydration after Lufenuron + Milbemycin Oxime + Praziquantel (Sentinel Spectrum) 47 reports · 0.5% of its reports

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