How to Get Rid of Fleas on Dogs and Cats

They bite. They cause itching. They drive your pet crazy. Fleas can be a serious frustration for your dog or cat – and they can be a serious health hazard too.

Found all over the United States, these tiny, blood-sucking pests play a role in the transmission of parasites as well as several canine, feline and human disease-causing organisms.

Fortunately for you and your dog or cat, Comfortis® (spinosad) works quickly to protect your pet from fleas. Comfortis starts killing fleas in 30 minutes of the first dose and killed 100% of fleas on dogs and 98% of fleas on cats in just four hours in controlled laboratory studies.


  • It provides flea protection that lasts a full month.
  • It kills fleas before they can lay eggs.
  • It can't be washed, rubbed or shaken off.

Learn more about Comfortis and why it’s ideal flea protection for families with children and households with more than one pet. Like all medications, keep Comfortis out of reach of children.

Learn more about Comfortis

Ask a Veterinarian

These two videos by veterinarian Jeff Werber, DVM, answer common questions by explaining fleas in more detail, how they thrive and how you can protect your pet and family from an ongoing infestation.

Comfortis is for both dogs and cats. It’s approved for use in cats 14 weeks of age or older and 4.1 pounds of body weight or greater. It’s approved for dogs 14 weeks of age or older and 5.0 pounds of body weight or greater.

How Can Fleas Harm My Dog and Infest My Home?

If I still see fleas on my dog, is my flea treatment working?