Why can’t I use dog flea products on my cat?

Owners looking to save some money when treating multiple pets with fleas may question their veterinarians' warning not to use dog products to treat cats.

But even if you only use a small dose of a flea treatment not meant for cats, you may be putting your pet at risk. It's important to buy different products to treat animals of different sizes and species, even if they all have fleas at the same time. If you're unsure which products are safe for your animals, call a vet for a consultation.

Chemical sensitivity

Can you use dog flea treatment on cats - Golden Retriever dog and British short-haired cat

Keep an eye on cats after a dog is treated, as cats may lick or rub against the area you treated on the dog.

The difference between flea control products for dogs and cats is a chemical called permethrin. According to the Pet Poison Helpline, this chemical is very safe for dogs and is common in flea sprays and drops. Cats, though, are especially sensitive to it and many of its variants. The chemical is derived from chrysanthemum plant and appears commonly in a synthetic form. Cat are unable to properly process it, and because of this it can make them sick. The natural version, called pyrethrins, is used instead in products meant for cats. Both versions of the chemical are safe for dogs, but owners should still buy a separate product for each pet to assure they're giving the proper dosage.

What to do if you use a dog flea treatment on your cat

Because the product can be harmful to your cat, there are a few steps that you should take if you apply the wrong flea treatment. The PPH said that if your pet shows any unusual symptoms such as drooling or agitation after application, you should bathe the pet in warm water with a gentle dish soap. PetMD noted that most symptoms resolve between 24 to 72 hours. If any pet shows more serious symptoms after a flea treatment application, bring him or her to your veterinarian.

For your pet's health and safety, avoid trying to save a few dollars by using expired medications or medications meant for animals of a different species or size. Also, keep an eye on cats after a dog is treated, as cats may lick or rub against the area you treated on the dog.

Always be sure to buy separate and appropriate products for all your different animals. For instance, if you get Hartz® flea drops for your dog, be sure to also get the cat-specific Hartz® flea drops instead of trying to use the same product for both.

Hartz UltraGuard ProMax Flea & Tick Collar for Dogs & Puppies - Gray
Hartz UltraGuard ProMax Flea & Tick Collar for Cats & Kittens - Purple