Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut elit tellus, luctus nec ullamcorper mattis, pulvinar dapibus leo.

Flea and Tick Medicine Poisoning in Dogs

What Is Flea and Tick Medicine Poisoning in Dogs?

Flea and tick medicine poisoning in dogs can occur when the medications designed to protect them from these parasites are not administered according to guidelines. While it’s crucial to safeguard your dog against flea and tick-borne diseases, it’s equally important to prevent toxicity by using these medications properly.

Certain substances effective against fleas and ticks, such as pyrethrins and pyrethroids, can be harmful to pets if they’re exposed to them in large amounts. Pyrethrins, derived from the chrysanthemum flower/plant, and pyrethroids, synthetic versions of pyrethrins, are commonly used in flea and tick prevention products. While pyrethrins are seldom found in daily use products, pyrethroids are frequently present in home insect control products and common flea and tick preventives.

Dogs may encounter high doses of pyrethroids in flea and tick preventives, as well as lower concentrations from household insect sprays, foggers, and granules. Another class of flea and tick prevention medications, called isoxazolines, has been associated with toxicity. These medications, including Bravecto (topical and oral), Simparica, Simparica Trio, NexGard, and Credelio, were the first oral flea and tick products and are highly effective. However, improper administration or overdose of isoxazoline-containing preventives can lead to toxicity.

It’s essential to use these preventives safely by ensuring the correct dosage is administered. While they effectively protect against fleas and ticks, they can pose risks if not used properly.


Symptoms of flea and tick medicine poisoning in dogs can vary depending on the type of medication and how it was administered. Here are the symptoms associated with different types of poisoning:

Pyrethroid-based topical flea and tick preventives, especially “spot-on” formulas, may lead to symptoms within 15 minutes to several hours after application:

  • Tingling sensation leading to excessive itching or scratching
  • Intense itchiness
  • Agitation or restlessness
  • Rolling around on the back or attempting to bite the back
  • Vocalization such as crying or whimpering

Pyrethrin and pyrethroid toxicity from oral ingestion typically show signs within an hour of exposure:

  • Drooling
  • Vomiting
  • Loss of appetite
  • Gagging or hacking
  • Agitation

In rare cases, ingestion of bifenthrin, often found in liquids and granular fire ant products, in large concentrated amounts, can cause:

  • Tremors
  • Twitching
  • Shaking
  • Difficulty standing or walking
  • Weakness
  • Seizures
  • Death

Isoxazoline, commonly present in oral flea and tick preventatives, can result in symptoms like:

  • Muscle tremors
  • Difficulty standing or walking
  • Seizures

If you suspect your dog is experiencing toxic side effects or has been exposed to pyrethrins, pyrethroids, or other harmful substances, it’s crucial to contact your veterinarian, ASPCA Poison Control, or a Pet Poison Helpline immediately for potentially life-saving treatment advice. Depending on the severity of the symptoms, seek emergency veterinary care promptly.


The causes of flea and tick medicine poisoning in dogs stem from the formulations of pyrethrins and pyrethroids, which vary based on their intended use. These chemicals are available in different concentrations, with higher concentrations deemed safe for use on dogs. However, cats are more sensitive to these substances and cannot metabolize them effectively.

These chemicals are commonly found in various products, including:

  • Home and outdoor yard and garden insecticides, which are available in liquids, sprays, granules, and foggers
  • Over-the-counter medicated flea shampoos
  • Topical flea and tick preventives


Following a thorough physical examination, veterinarians typically diagnose flea and tick medicine poisoning in dogs presumptively, especially when there’s a known or suspected history of exposure to products containing pyrethrins or pyrethroids, or ingestion of flea/tick medicine. In a presumptive diagnosis, veterinarians have compelling reasons to believe that a particular substance or event is causing the issue, even if they cannot confirm it with a specific diagnostic test.


Treatment for flea and tick medicine poisoning in dogs varies depending on the severity of the toxicity and the symptoms exhibited. It may involve outpatient care or hospitalization for supportive treatment. Unfortunately, there is no specific antidote for this type of poisoning.

Treatment typically involves promptly removing the product by bathing the dog with a liquid dish soap such as Dawn, Joy, or Palmolive to eliminate the greasy substance. Rinsing the mouth with copious amounts of water is also recommended, and if necessary, a garden hose can be used to flush any ingested toxins from the mouth.

In cases where neurological symptoms are present, hospitalization for up to three days may be necessary to minimize the severity of clinical signs. Supportive care during hospitalization may include repeat bathing, intravenous fluids, anti-nausea medications, muscle relaxants, and seizure medication. Additionally, veterinarians may monitor the dog’s temperature, blood sugar levels, and kidney function, as these parameters can be affected by toxicity.

Living and Management

When flea and tick medicine poisoning in dogs is promptly recognized and treated early, the prognosis is generally favorable. However, if your dog experiences neurological signs, kidney problems, seizures, and elevated body temperature, the prognosis tends to be less optimistic.

Mild adverse reactions, such as excessive drooling, paw flicking/scratching, and ear twitching, are often temporary and can resolve on their own. Although drooling may persist for several days following the use of a flea-control product, most mild to severe clinical signs typically improve within three days. Regular monitoring and appropriate management contribute to a more positive recovery outcome for affected dogs.


To prevent accidental exposure, it’s crucial to meticulously follow all instructions provided with flea and tick preventives and insecticides. Ensuring dogs receive the appropriate dose for their body weight is paramount. Avoid administering more than one drug simultaneously to prevent accidental overdose. Refrain from using part of a larger-sized dose or multiple smaller doses, as this could lead to overdose and an elevated risk of poisoning. If uncertain, it’s advisable to bring your dog to the veterinarian for a weigh-in and proper guidance.

Flea and Tick Medicine Poisoning in Dogs FAQs

Is recovery possible for dogs affected by flea and tick medicine poisoning?

With prompt treatment, dogs can recover fully from flea and tick medication poisoning or toxicity. Early detection of clinical symptoms is crucial for the most favorable prognosis.

How long does flea and tick medicine poisoning typically last?

While symptoms may persist for several days following product use, most clinical signs will resolve within one to three days.

Scroll to Top