Frontline Flea Spray on Pregnant Dog

by Catherine
(Dublin, Ireland)

Reader Question: Frontline Treatment on Pregnant Dog

I have looked after dogs since I was 12 yrs old (30 years) and I never experienced fleas due to use of good prevention medication, collars etc. I think I brought fleas in with me from neighbours house while feeding her cat for a week.

My Shitzu who I hope is pregnant, she would have been 3 weeks pregnant scratched and I noticed fleas, panicked and sprayed her with Frontline Spray. She had a bad skin reaction and started to scratch even more with chicken pox marks and swellings. This rash quieted down after a week and vet said she seemed ok now.

My question is will the Frontline Spray damage the puppies?

Suggestion from Our Veterinarian


I do not think you have anything to worry about. While the US label on Frontline Spray says owners should consult a veterinarian before using the product on pregnant bitches, the information provided with the product in other countries flat out says it safe for use during pregnancy.

Fipronil, the active ingredient in Frontline, is not absorbed into the body but stays in the sebaceous (oil producing) glands of the dog to which it was applied. Therefore, I do not see how it could have an adverse effect on the puppies your dog is carrying.


Jennifer Coates, DVM

Click here to post comments

Join in and write your own page! It's easy to do. How? Simply click here to return to Fleas.