Can You Use Frontline for Dogs on Cats?

Frontline for dogs or frontline plus is a flea preventive medication that’s available for both canines and felines. It is a topical medication that needs to be applied to the pet’s skin once a month. Several pet owners are of the opinion that it’s safe and economical to use frontline for dogs on cats but this isn’t true. Frontline for dogs contains two active ingredients namely fipronil and s-methoprene in certain amounts. The same ingredients are present in the cat formula but in varying amounts. Since pets are very sensitive to medications it’s important to avoid using dog formulas on cats or vice versa.

What’s the Difference between the Two?

Frontline plus for dogs contains 9.8 percent of fipronil and 8.8 percent of (S) methoprene. The cat formula contains 9.8 percent of fipronil and 11.8 percent of (S)methoprene. The feline version of the medication contains S-methoprene in a larger amount so the ratio of fipronil to (S) methoprene varies for dogs and cats. If the combination of these two ingredients is altered, the cat may develop certain reactions and suffer from side effects.

You should therefore, avoid giving your cat the formula that’s specifically prepared for dogs. Cats are also more sensitive than dogs. For this reason, you need to be very careful when you use any over the counter drugs like Frontline Plus to treat your pet.

How does Frontline Work on your Cat?

The medication, if used appropriately, kills adult fleas within 18 hours and adult ticks within 2 days. Since (S) methoprene inhibits the growth of insects and parasites, it destroys flea larvae and eggs that are present on your cat’s body.

The medication has to be applied to the cat’s body on the area between the shoulder blades. Your cat shouldn’t be allowed to lick the product once it has been applied.

Dosage and Administration

Frontline plus shouldn’t be applied to kittens that are under 8 weeks of age. Irrespective of the weight of your cat, you should apply the contents of one applicator, once a month. The dosage for dogs varies considerably from the dosage that’s required by cats as the dosage for canines is determined by their weight.

In order to prevent any confusion, it’s important that you stick to the feline formula to treat your cat.


The medication shouldn’t come in contact with the cat’s eyes, mouth or nose. You should also wear gloves or wash your hands thoroughly after your treat your pet with this topical solution.

Some pets may suffer from mild irritation at the site of application. If this irritation persists or becomes worse, conduct a vet check. Although the product is safe for use on pregnant and nursing animals, it should only be used on such pets after prior vet approval has been obtained.

Tips for Pet Owners

If you have been treating your cat with another flea medication, avoid using frontline plus without discussing the same with the vet. Since most flea medications contain insecticides and insect growth regulators, your cat may suffer from drug interactions if you use a combination of medications.


  • Make sure you store the product in an appropriate manner.
  • Keep it away from both pets and children.
  • Call for emergency medical help if you have accidentally overdosed your pet.
  • Dispose the medication according to the instructions listed on the package.

Frontline plus is an effective formula, but you shouldn’t only rely on medications to keep fleas and ticks at bay. Consider treating your home and outdoor areas and wash your pet’s bedding regularly to get rid of flea eggs and larvae that exist in your home.