Hair loss after Fipronil + S-methoprene (Frontline Plus) in dogs
The FDA has received 113 reports of hair loss in dogs after Fipronil + S-methoprene. That is 3.8% of all reports for this medicine, compared with 1.0% across reports for all dog medicines, so it is reported unusually often with this medicine.
113Reports
59%Marked serious
12%Recovered
0.9%Died or euthanised
17 daysTypical onset
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How soon it started
How the animals did
Problems reported at the same time
Age of the animals
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 hair loss in dogs?
- 113 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 17 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).
Hair loss with similar medicines
- Hair loss after Spinosad (Comfortis) 503 reports · 0.9% of its reports
- Hair loss after Lufenuron + Milbemycin Oxime (Sentinel) 227 reports · 0.9% of its reports
- Hair loss after Imidacloprid + Moxidectin (Advantage Multi) 452 reports · 3.4% of its reports
- Hair loss after Nitenpyram (Capstar) 195 reports · 1.8% of its reports
- Hair loss after Lufenuron + Milbemycin Oxime + Praziquantel (Sentinel Spectrum) 46 reports · 0.5% of its reports
- Hair loss after Flumethrin + Imidacloprid (Seresto) 135 reports · 5.9% of its reports
- Hair loss after Imidacloprid 43 reports · 2.3% of its reports
- Hair loss after Fipronil 22 reports · 1.6% of its reports
- Hair loss after Lufenuron 45 reports · 4.4% of its reports
- Hair loss after Imidacloprid + Permethrin + Pyriproxyfen 33 reports · 4.5% of its reports
All reported side effects of Fipronil + S-methoprene in dogs · Medicines most reported with hair loss