News From Terre Haute, Indiana

June 3, 2012

PAW PRINTS: Flea medications containing permethrins can be deadly for pets

Niki Laviolette
Special to the Tribune-Star

TERRE HAUTE — Fleas are annoying pests. They cause our pets to become anemic, experience dermatitis, and contract tapeworms. Controlling these insects are an important part of taking proper care of our pets in order to help keep them healthy.

Popular products that are purchased by consumers to aid in controlling fleas and ticks include those that are applied to the back of the pet.

Typically, this type of product usually lasts for approximately 30 days. Some flea products that can be bought over-the-counter contain the active ingredient, permethrin. Modified pyrethrins are synthetic insecticides that are derived from the chrysanthemum plant. The chemical properties of permethrin allow for the chemical to spread by itself in skin oil (called translocation). Permethrin is not waterproof, and because it has been in use for 20 years, many fleas are resistant to it.

Topical flea products containing permethrin are usually labeled “for dogs only.” Although permethrins are typically safe for dogs, they are toxic to cats, often resulting in death.

Toxic effects can also be seen in cats that are in close physical contact with dogs that have been treated through grooming and sharing beds. Pyrethrins are toxic to cats due to metabolic deficiencies only found in cats.

A report of 286 cases where canine flea spot permethrin was applied on cats, 97 percent had signs of poisoning. There is no reason to apply any product containing permethrin on a cat to control fleas as there are plenty of flea products available for cats that do not contain permethrin.

Permethrin is a neurotoxin that can cause symptoms which include muscle tremors, hyperexcitability, depression, vomiting, uncontrollable seizures, anorexia and death. Symptoms can develop within a few hours to three days following exposure. Typical treatment includes hospitalization with continuous intravenous fluids. It is important to eliminate any existing product from the body and to control muscle tremors and seizures. It’s also important to bathe the cat in lukewarm water using mild dish soap (not using hot water or flea shampoo).

According to the EPA, permethrin is a possible human carcinogen. Studies have shown permethrin to increase the frequency of lung and liver tumors in mice.

Permethrin also disrupts the growth and development of tadpoles with increased frequency of tail abnormalities at the lowest concentrations (0.1 ppm), and permethrin also effects brain function.

Seek the advice of your veterinarian when choosing the most appropriate, safe and effective flea medications for your pet.

Always observe your pet closely after applying flea products. If your cat demonstrates unusual behavior, becomes depressed, weak, or uncoordinated, contact your veterinarian immediately. Remember to read the label and follow the directions when using any pet product. It could save the life of your pet.

• Charlie

Meet Charlie! He’s on the prowl for a new home! He would like good food, lots of love and a nice warm bed! Charlie loves people and purrs when you pet and talk to him. Charlie is vetted and ready to go home with an approved application. Slide on in to the Terre Haute Humane Shelter and meet the cool dude. You just might meet your next best friend.