What Happens If My Cat Licks Flea Treatment?

The saying goes, “Curiosity killed the cat,” wasn’t just made up for nothing. Cats are naturally curious. They will sniff, taste, and investigate things that are new to them.

While cats usually stay away from flea and other parasite prevention products, they are still not exempted. Even when you have entirely followed what the manufacturer recommends about applying the product at the back of the neck, they’ll always find a way to lick it.

They may bend their necks to reach far back, reach with their tongues, or paw at the area and subsequently lick their paws. Anything they’d do to feed their curious cat mind.

Flea and Tick Medicine Toxicity

Flea prevention products usually have pyrethrin and pyrethroid. These are typically the insecticides used against flea and tick infestations in pets.

Pyrethrin is derived from Chrysanthemum cinerariafolium plant. While they appear to be all-natural, they have a potent mixture of six chemicals that are toxic to insects.

They are not just used for controlling fleas and ticks but also other pests, such as mosquitoes, moths, ants, etc. This pest-controlling compound work by actively targeting the nervous systems of insects.

Pyrethroid, on the other hand, is similar to pyrethrin. Derived from the same plant but are synthetic, making them longer-lasting.

Other types of flea products contain organophosphates. This insecticide works by damaging enzymes in the body that are critical for controlling nerve signals. (1)

These products are tested safe and effective when properly used. They also room for the risk of toxicity and other undesirable health consequences if misused.

And while we also practice being responsible pet owners, we can’t control when our cats decide to be curious and lick the flea solution out.

Tick and Flea Treatment’s Effect To Your Cat If Licked/Swallowed

Pyrethrin and Pyrethroid, although plant-based are toxic to your felines. Pyrethroid (2) alone includes allethrin, cypermethrin, deltamethrin, fenvalerate, fluvalinate, permethrin, phenothrin, tetramethrin, and etofenprox.

These may cause an adverse reaction that will affect the cat’s nervous system. It reversibly prolongs sodium conductance in nerve axons that results in repetitive nerve discharges.

Such reactions happen more recurrently in cats than dogs because of higher sensitivity. Most of the furballs at a higher risk are the very young, old, sick, or debilitated.

Feline’s reaction to pyrethrin and pyrethroids may become worse if they are hypothermic.

Symptoms and Types of Flea and Tick Medicine Poisoning in Cats

Signs of flea and tick solution poisoning in cats may manifest from 1 to 12 hours after application. They may also vary in the type of medicine.

Cats, as have previously mentioned are particularly sensitive to pyrethroids. When (accidentally) treated with strong permethrin-containing products labeled for dog use, they consequently develop muscle tremors, incoordination, seizures, hyperthermia, or worst – death within hours if treatment was not applied to the toxicity.

Products with phenothrin may also result in similar but less severe clinical effects. A great deal of these products has been discontinued because they cause such adverse clinical reactions.

Flea and tick treatment poisoning may also demonstrate other symptoms such as;

Allergic reactions –

  • Hives
  • Congestion
  • Itching
  • Extreme sensitivity
  • Shock
  • Respiratory distress
  • Death (worst case)

Idiosyncratic reactions –

  • Mimics toxic reactions at much lower doses

Mild reactions-

  • Excessive salivation
  • Paw flicking
  • Ear twitching
  • Mild depression
  • Vomiting
  • Diarrhea

Moderate to serious reactions-

  • Protracted vomiting
  • Diarrhea
  • Depression
  • Incoordination
  • Muscle tremors (totally different from paw flicking or ear twitching)

Other symptoms you may notice include difficulty in breathing, small pupils, weakness or falling over and drooling.

Be extra careful about flea and tick treatment with organophosphate as their toxicity can be rapidly deadly, depending on the components and the dose the feline is exposed to.

Causes of Flea and Tick Medicine Poisoning in Cats

Cats having less efficient metabolic pathways make them more prone to insecticides poisoning than dogs. Unfortunately, their extensive grooming habits and their long hair coats that retain large quantities of topically applied products contribute more to the disastrous situation.

They are also inclined even more when they have abnormally low body temperatures, such as after bathe, anesthesia, or sedation.


If your cat experiences flea control product poisoning, contact your veterinarian.

And, while waiting for an appointment, most recommend that you immediately wash your fur baby with warm water and a mild detergent, like Dawn® dishwashing liquid. Please make sure you pat them dry and keep them warm. You wouldn’t want to lower down their temperature.

At the clinic, the veterinarian may perform a thorough physical exam on your feline. He will consider the cat’s background history of symptoms and possible incidents that could have led to this condition.

Treatment, Living, and Management

Reactions like hypersalivating, paw flicking, and ear twitching are usually mild and self-limiting. Spray product saturation in cats may be relieved with a warm towel and brush.

If the symptoms progress to tremors and body weakness, your cat may require hospitalization where they will be stabilized with fluid support, seizure control, and body temperature maintenance.

Once the cat gets stable, hypersalivation may recur for several days. This is because the cat uses their mouth and paws to clean their entire bodies. Residue from flea treatment may cause them this, but nothing to worry about.


Fleas can be an annoying situation for our furbabies. Relying on flea medications is usually the last resort. However, with risks like these, it can alleviate the situation even more.

As luck would have it, ASPCA Animal Poison Control Center (APCC) has a guide to help us use flea medications correctly.

  • Make it a habit to read all of the labeled information before applying medications to your pet. See if your cat is of the right age for the product, if the medication is for cats, how it is applied. Be conscious of any health risks like allergies.
  • Do not use more than one medication on your pet unless indicated by the veterinarian.
  • Ensure that your vet is your primary source of information. Do not perform uneducated treatments for your pets.
  • The Internet may recommend some steps which may not be entirely safe. Tea tree oil and garlic, for instance, cause severe and potentially life-threatening signs in pets. If you feel the need to use an alternative flea control, make sure to consult with your pet’s vet first.
  • Always be certain that you have double-checked everything before applying flea medications to your pet.
  • If you are in a household with multiple pets and the flea season has forced you to treat all of the pets in the home, take time before applying to each one. You wouldn’t want to confuse one medication for another


Most poisonings from flea treatment are usually a result of not following label directions. Always be on the lookout for the public materials provided by treatment manufacturers regarding the product’s oral ingestion toxicity.

And, as with most cat emergency cases, always reach out to your veterinarian.