What happens if you put dog frontline on a cat? Permethrin is used in some flea spot-on products made for dogs, and occasionally (in lower doses) in flea powders and collars for cats. Unfortunately, exposure to concentrated permethrin (as in some dog spot-ons) can result in serious illness and even death in cats.
What is the difference between cat and dog frontline? Despite the fact that fipronil and methoprene are approved for use on both dogs and cats, there is a major difference between the two types of Frontline Plus. Comparing the two products, Frontline Plus for Cats has a higher concentration of active ingredients than the dog version.
Can I use dog flea treatment on my cat? The safest answer is no. We strongly recommend to carefully read the instructions of any product you intend to apply to your pet, as many supermarket dog flea treatments are extremely toxic to cats.
Why can’t you use dog flea medicine on cats? “Cats can’t process those medications the same way a dog would. So even if you were use just a small drop of your dog’s topical flea prevention on a cat, their body is not going to be able to metabolize it and they can get very serious side effects.”