Cats and Flea Control Products

by Jill A. Richardson, DVM
Veterinary Poison Information Specialist ASPCA/National Animal Poison Control Center

Fleas can be a major problem for cat owners. Not only are these tiny creatures a nuisance, they are also the cause of many diseases such as flea anemia, flea bite dermatitis, and tapeworm infestation. Therefore, strict flea control is a necessary step in the health care of any cat. The eradication of fleas from our animals and our homes necessitates the use of products containing insecticides, either in the form of a mousses, spot-ons, oral suspensions, powders or spray mists. While there are many safe insecticide products available for use on cats, caution must be used as cats are generally more sensitive to most insecticides. Cat owners should be extremely careful when using flea products on or around their cats. Products should be used strictly according to their label directions.

The following are some guidelines for cat owners to follow when choosing and applying a flea control product:

  • Never use insecticides on very young kittens, pregnant queens, debilitated, or elderly cats without consulting your veterinarian. With such cats, you may want to consider avoiding the use of some insecticides directly on your pet. Instead, you could comb the fleas off the cat with a flea comb then submerge the fleas in a small container of soapy water. This would also be a good alternative for cats who love being groomed but who violently refuse baths or the application of a spray.
  • Before using ANY product on your cat, read the label instructions completely. If you do not completely understand the instructions, you should contact the manufacturer or your veterinarian for clarification. Observe the species and age requirements listed on the label. NEVER use a product labeled “for use on dogs only” on your cats. Cats react very differently than dogs to some insecticides. Some dog products can be deadly to cats, even in tiny amounts.
  • Use caution when using products that contain organophosphates in your house or on your cat. Cats are more sensitive to organophosphate insecticides than most other animals. Currently, there are few flea products in the United States labeled for use on cats that contain organophosphates as an active ingredient. The few that can be used on cats contain a small concentration of organophosphate. However, many household sprays and products that are specifically labeled “for use on dogs only” are widely available. Again, avoid these dog products! In some cases, exposed cats can start showing signs within hours. Symptoms would include drooling, depression, labored breathing, weakness, and convulsions. Without prompt and proper treatment, many exposures could lead to the animal’s death. With appropriate treatment by a veterinarian, the survival chances are much higher.
  • NEVER use flea control products that contain “permethrin” on your cats, unless they are specifically labeled for use on cats. There are some products that are labeled for use on cats that contain small concentrations of permethrin, usually less than 0.1%. When used according to the label instructions, these can be used safely in cats. However, there are many permethrin products available over the counter for use on “dogs only.” These contain high concentrations (45-60% ) of permethrin insecticide. These permethrin products have a good range of safety when used on dogs, but, even a few drops of concentrated permethrin could be lethal to cats. The reason for this species difference is yet unknown. Exposed cats can develop uncontrollable seizures within hours of concentrated permethrin application. Some may tremor for several days. The fatality rate of untreated cats exposed to such products is very high. Proper treatment by a veterinarian can often prevent death.
  • Always use caution when using shampoos, sprays, topical spot-ons, or mousse near your cat’s eyes, ears, and genitalia. Inactive ingredients can cause irritation to these sensitive tissues.
  • When using a fogger or a home premise spray, make sure to remove all cats from the house for the time period specified on the container. Food and water bowls should be removed from the area also. Allow time for the product to dry completely before returning your cats to your home. Open windows or use fans to “air out” the household before returning your cats to the treated area. Strong fumes can be irritating to your cat’s eyes and upper respiratory system. If you are uncertain about the usage of any household product, contact the product’s manufacturer or your veterinarian to explain the directions BEFORE use of the product.
  • Insect growth regulators like lufenuron, methoprene, and pyriproxyfen can be used in combination or alone with flea control products. They can help break the flea life cycle by inhibiting flea maturation. Growth regulators have minimal adverse effects and can improve the efficacy when used in combination with adult flea insecticides.
  • Just because a product is labeled to be a “natural” product does not mean that the product is completely safe. Many such “natural” products can be harmful when used inappropriately on cats. For example, d-limonene and linalool are citrus extracts that are used as flea control agents. Though they are natural products, they still can have serious side effects if used on sensitive cats or if used improperly.
  • Observe your cat closely after using flea products. If your cat exhibits unusual behavior, or becomes depressed, weak, or uncoordinated you should seek veterinary advice.
Once again, read the label. This could save the life of your cat!

Please Note: CFA provides the feline health information on this site as a service to the public. Diagnosis and treatment of specific conditions should always be in consultation with one’s own veterinarian. The Cat Fanciers’ Association, Inc. disclaims all warranties and liability related to the veterinary advice and information provided on this site.