Flea and tick control products for cats come in a variety of forms: collars, powders, dips, sprays, and spot-on products, to name a few. Although there are several different types of active ingredients used for flea and tick control, the most common ingredient is pyrethrin, an insecticide that is used in pet products to repel fleas and other insects as well as to repel insects from food plants. A natural organic compound derived from the seed casings of the chrysanthemum flower, this highly effective insecticide attacks the nervous system of insects while remaining harmless to mammals, as long as the levels are very low.
Toxicity most commonly occurs as a result of improper use of flea and tick control products, particularly over-application or use of a product that was formulated for a different species. Cats are much more sensitive than dogs are to pyrethrins, and because the level of pyrethrins will be higher in a flea repellent that has been formulated for dogs, cats will commonly fall ill after being treated with a flea or tick product made for dogs.
The synthetic versions of pyrethrin, permethrin and other pyrethroids, have an even higher incidence of toxicity for cats when used improperly (the toxicity risks also increase for humans). Users can distinguish other synthetic pyrethroids in insecticide products by looking for ingredients that end in "thrin" in the ingredient list.
What to Watch For
- Excessive drooling
- Muscle tremors, staggering (ataxia)
- Possibly seizures
- An agitated or over excited state
- Vomiting, diarrhea, difficulty breathing or hyperthermia (less common)
- Evidence that a pyrethrin or permethrin containing product was applied recently
Toxicity is caused by an overdose of topical (external) flea and tick control products containing pyrethrin, permethrin or other pyrethroids. It can also result from using pyrethrin containing flea products made for dogs, which are made with higher levels of pyrethrin — levels that are unsafe for cats. Toxicity can also occur as a result of ingestion, such as when a cat grooms itself or licks another animals (including dogs) that have been treated with a pyrethrin product.
If your cat is wearing a flea collar or other insect repelling device, remove it.
Call your veterinarian or the Pet Poison Helpline at 1-855-213-6680 immediately to determine if your cat has been poisoned.
Diagnosis is based on symptoms and history of recent exposure to pyrethrin-containing products.
Treatment will be given to control symptoms as needed. Most commonly, medications to control tremors and seizures, along with intravenous fluids to maintain hydration. If symptoms are severe enough, your cat may need to remain hospitalized for a few days until symptoms subside.
Because pyrethrins are so effective at insect control, products that are formulated for insect control in and around the home, including gardens, can also be found in the cat’s environment.
Living and Management
There are usually no long-term effects from overdosing if the cat receives immediate treatment. If you used a pyrethrin containing flea and tick product that was formulated for cats and you are sure that it was applied properly, and your cat still showed signs of toxicity, do not use a product that uses pyrethrins. Talk to your veterinarian about a good alternative for your cat.
The most important way to prevent overdose is to read labels and follow the directions: how much, how often, and how to apply the product on the cat. If you cannot find this information on the label, do not use the product. Make sure the product is labeled for cats; you cannot substitute with flea and tick products made for dogs.
In addition, all flea products have a minimum age for use, kittens must reach a certain age before they can be treated with any kind of flea or tick product. Most products also have a minimum weight. The amount (or dose) of pyrethrin used in a formula often will vary according to a cat’s weight. Make sure that you are choosing the formula that best matches your cat’s age and weight. Also keep in mind that because cats groom each other, you will need to keep them separated after applying a flea or tick product until the product has dried.
Common synthetic pyrethroids: bifenthrin, permethrin, allethrin, tetramethrin, cyfluthrin, cyhalothrin, cypermethrin, deltamethrin