Permethrin Poisoning in Cats

Permethrin is a substance in insecticides and treatments for preventing flea and tick bites and infestations, including topical solutions, collars, powders, and shampoos for dogs and cats. While dogs can tolerate permethrin very well when it’s applied to their skin, cats are sensitive to the substance and can get ill if they come into contact with too much of it. The dose of permethrin that is given to even small dogs is enough to poison a cat because the cat is missing an enzyme in the liver that would metabolize it effectively. As a result, permethrin builds up in the cat’s bloodstream and causes unpleasant symptoms that can lead to death. 

Permethrin poisoning is a medical emergency, and must be treated by a veterinarian or emergency clinic immediately. The sooner the signs of poisoning are noticed and treated, the better the chance of survival.

Symptoms of permethrin poisoning can occur throughout the body because the toxin travels in the bloodstream. It does, however, target the neurological system most often. Signs and symptoms include:

• Excessive salivation or drooling
• Incoordination, including problems walking, jumping and standing
• Agitation and restlessness
• Vomiting
• Shaking, twitching, or tremors
• Hiding
• Shortness of breath
• Fever
• Oversensitivity to touch and sound
• Seizures
• Blindness (rarely)

In a retroactive study of 42 cats who had been diagnosed with permethrin poisoning, it was found that the overwhelming percentage had been accidentally administered a dog-strength flea and tick preventative topical solution. 

• Administration of dog-strength permethrin to a cat
• Contact with a dog who has been treated with permethrin less than 12-24 hours before
• Cat grooming a dog in the area where the spot-on treatment was placed
• Lying on furniture where a treated dog had been sitting
• Direct skin-to-skin contact

Clothing that has been impregnated with permethrin to repel insects does not pose a risk for a cat because the concentration of the substance is quite low and there is little chance of transferring it.

Your veterinarian will perform a physical examination to confirm that your cat’s symptoms are caused by permethrin poisoning. The exam will include taking the cat’s temperature, blood, and urine samples for testing for renal involvement or impairment. The veterinarian will test for neurological symptoms that may not yet be present, such as reflexes and balance. Commonly, the symptoms may seem to have become less severe at one point, only to return.

Be sure to relate all of the symptoms you have observed, including the duration and severity of each one, as well as any known exposure to permethrin or any other toxic chemicals, medications, or animals that may have transferred the toxin. Common examples include through the skin, or ingestion through licking.

There is no antidote for permethrin poisoning, so treatment aims to remove as much toxin as possible and support the cat’s body to help them recover. An exposed cat should be hurried to the veterinary hospital or emergency clinic for treatment immediately if it’s suspected they may have come into contact with permethrin. Typically, the cat will be confined to the hospital for 48 to 72 hours.

Decontamination

The veterinarian and staff will bathe the cat with a diluted solution of liquid dish detergent and water to remove any traces of the permethrin from the skin. 

Intravenous fluids

IV fluids will likely be given to help flush the toxin out of the system, as well as to support the cat’s overall condition. If fever is present, IV fluids may also help reverse it by hydrating the cat.

Medications

Anti-seizure medications or sedatives may be given to alleviate tremors and prevent seizures. These could include methocarbamol, benzodiazepines, propofol and/or general anesthesia.

Nutritional support

If the cat hasn’t been eating normally, the veterinarian might consider providing nutritional support via parenteral feeding. This would require placing a separate IV tube to administer a nutrient solution.

Intravenous lipid emulsion (ILE)

This relatively new treatment involves administering lipids (fatty acids) through an IV. The lipids serve as “sponges” that absorb the toxin and remove it from the body. An article in the Journal of Veterinary Emergency and Critical Care stated that after receiving IV lipid emulsion treatment, along with methocarbamol, two poisoned cats recovered completely from the toxicity. No adverse effects appeared with the treatment.

Monitoring

The veterinary staff will monitor the cat during its stay in the hospital to ensure that symptoms are steadily decreasing with no recurrence. They will also be monitoring for overall condition and nutritional status.

After your cat begins to recover, follow up appointments are generally scheduled to assess the cat’s progress back to full health and to ensure there is no relapse. Blood sugar and kidney function may be monitored for a period of time as well.The prognosis for a cat with permethrin poisoning is good if the cat is taken for care soon after the exposure. Full recovery can take 3 to 7 days.

Education of the pet parent about how to prevent poisoning in the future is an important part of the cat’s care. For example, only use flea and tick treatments meant for cats, and prevent your cat from having access to a dog who has recently been treated. If necessary, put a t-shirt on the dog so your cat can’t come into contact with their skin where the preventative was applied. Put all permethrin products, including indoor and outdoor insect repellants, out of reach. When treating the cat for fleas and ticks, in addition to being sure to use only a cat formula, check that the dosage is correct for your cat’s weight.

Permethrin poisoning can be expensive to treat. If you suspect your cat is at risk of permethrin poisoning, start searching for pet insurance today. Wag! Wellness lets pet parents compare insurance plans from leading companies like PetPlan and Embrace. Find the “pawfect” plan for your pet in just a few clicks!

The average cost to treat a cat with permethrin poisoning can range from $200 to $3,000 or more.