Aloha! You're speaking to Dr. Michael Salkin While any dog might suffer an idiosyncratic (peculiar) reaction to a drug, Frontline (fipronil) has a very wide safety profile and so although there's no manner in which I can prove that Megan didn't have such a reaction, I believe it's unlikely. My condolences for your loss of Megan. Frontline is not systemically absorbed. (Weil, 1997) Fipronil is detected on the hair shafts but is never detected in the dermis and adipose tissue, suggesting that it is absorbed and accumulated in the sebaceous glands, from which it is slowly released via follicular ducts. It has been tested and can be used in kittens and puppies as young as 8 weeks of age. It is easily removed by bathing in the first 48 hours after application before it is absorbed into the sebaceous glands. (Weil, 1997) In toxicity studies, the application of Frontline® spray to dogs and cats at a dose five times higher than recommended for 6 months did not cause any clinical, biochemical, hematological, or cutaneous abnormalities. (Consalvi, 1996) Oral doses equal to 87 pipettes in dogs and 20 pipettes in cats showed no adverse reactions beyond drooling and occasional vomiting. A few skin hypersensitivity reactions have been reported, most likely to the carrier. Please respond with further questions or concerns if you wish. I'm sorry that your question wasn't answered in a timely manner.
Thank you so much for your reply. Our vet did tell us that Frontline isn't systemic, so this confirms his advice.
Because her illness appears to have come from nowhere, we wanted to look at any possible cause.
Once again, many thanks for your advice. It has been very helpful
Andrew and Pam