CInsecticide Poisoning: Pyrethrin or Pyrethroid Toxicity
Understanding Your Pet's Medical Diagnosis
What is pyrethrin or pyrethroid toxicity?
Pyrethrin and pyrethroid are insecticides. Natural pyrethrin is found in chrysanthemums and related plants. The synthetic form of the insecticide is called "pyrethroid." Pyrethrin and pyrethroid are commonly found in flea and tick control products. Pyrethrin or pyrethroid toxicity is poisoning due to exposure to these insecticides. Exposure may be from swallowing (ingestion) of products that contain these insecticides or from contact with the skin when products containing pyrethrin or pyrethroid are applied directly to the hair and skin (topical application).
What causes pyrethrin or pyrethroid toxicity?
Pyrethrin or pyrethroid toxicity is caused by overuse or improper use of flea and tick products. Small dogs and cats are more sensitive to pyrethrin or pyrethroid toxicity because they have a relatively large body surface compared to their body mass, making it easier to overdose these small pets with topical insecticides. Cats can become poisoned from the accidental or intentional use of dog-only products, incorrectly diluted dips or sponge-ons, or accidental ingestion of insecticides. Pets with heart or thyroid disease can become seriously ill when stressed by normal bathing, dipping, or spraying. Animals also can have allergic reactions to pyrethrin and pyrethroid.
Anyone using any insecticide should read the manufacturer's instructions carefully before applying the insecticide. All instructions should be followed when using an insecticide. The pet guardian should check that the product is safe for use in cats. A good rule is that if the label does not say the insecticide is safe for use on cats, consider that it is harmful and do not use it on cats. The veterinarian should be consulted if the pet guardian has any questions about using an insecticide.
What are the signs of pyrethrin or pyrethroid toxicity?
Signs of pyrethrin or pyrethroid toxicity range from mild to severe. Mild signs include excessive salivation, paw flicking, ear twitching, mild depression, vomiting, or diarrhea. Moderate to serious signs are vomiting, diarrhea, marked depression, unsteady gait, muscle tremors, seizures, or death. Use of products labeled for dogs only on cats can lead to muscle tremors, unsteadiness, seizures, and death within hours. Allergic reactions are characterized by skin rash, red and hot areas of the body, itching, shock, breathing problems (respiratory distress), or death. Death is rare in allergic reactions.
How is pyrethrin or pyrethroid toxicity diagnosed?
Pyrethrin or pyrethroid toxicity is diagnosed by medical history and physical examination. A good history is important; all pesticides, medications, or other possible poisons with which the pet may have come in contact must be considered. The history of exposure, including the amount and frequency of product usage; type and severity of signs; and the onset and duration of signs are evaluated. Routine laboratory tests of blood and urine are not done unless needed to rule out other diseases and conditions that may cause similar signs. Blood tests can indicate other types of insecticides but not pyrethrins or pyrethroids. Tests to detect pyrethrins or pyrethroids in animal tissues or fluids generally are not available.
How is pyrethrin or pyrethroid toxicity treated?
The treatment for pyrethrin or pyrethroid toxicity depends on the severity of the signs. Adverse reactions to pyrethrins or pyrethroids are generally mild. Salivation, paw flicking, and ear twitching generally resolve without treatment. Pets that have been saturated with sprays should be dried with a towel warmed from a clothes dryer and brushed out. If signs continue or progress to tremors and unsteadiness, the pet should be hospitalized and bathed. The pet should be kept warm. Tremors and seizures are treated with medication administered intravenously (through a vein). Fluids may be administered intravenously to seriously affected pets. Activated charcoal is given to animals that have ingested large amounts of poison. This procedure is warranted only when large amounts of insecticide are swallowed; for example, when an undiluted bottle of dip is spilled and the contents are lapped up by a dog. Vomiting may be induced or the stomach may be flushed if indicated. The stomach can be flushed while the animal is under sedation with a breathing tube (endotracheal tube) in place.
What is the prognosis for animals with pyrethrin or pyrethroid toxicity?
The prognosis (outcome) for animals with pyrethrin or pyrethroid
toxicity depends on the amount of exposure. Proper application
of flea control products can reduce the incidence of adverse reactions.