Paroxetine (Paxil®) for Dogs and Cats

Overview of Paroxetine for Canines and Felines

Paroxetine, also known by the brand name Paxil®, is a prescription drug used to treat aggression, anxiety disorders, compulsive disorders, and other behavioral disorders in cats and dogs.
Behavioral disorders in dogs and cats are common reasons for veterinary visits. Behavioral problems are also a frequent reason for euthanasia of pets, especially when unacceptable or dangerous animal behavior is involved.
Recently, veterinarians have begun placing increasing emphasis on animal training and behavior modification, and animal behavior specialists have adopted drugs used to modify human moods and behavior for animal use. Paroxetine is one of these drugs.
This drug increases serotonin levels in the brain. Serotonin is a chemical that facilitates transmission of “messages” between brain cells. Its effects are very similar to those of another serotonin enhancing drug, Prozac® (fluoxetine).
Paroxetine is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian.
This drug is not approved for use in animals by the Food and Drug Administration (FDA) but may be prescribed legally by veterinarians as an extra-label drug.

In dogs, paroxetine is sometimes used to treat aggression, fear-based behaviors (such as storm and noise phobias), anxiety-based behaviors (such as separation anxiety), and compulsive disorders (such as acral lick dermatitis and compulsive tail-chasing).
In cats, paroxetine is used to treat aggression, excessive fearfulness, urine-marking, and compulsive behaviors (such as excessive grooming, tail-chasing and wool-sucking).

While generally safe and effective when prescribed by a veterinarian, paroxetine may cause unacceptable side effects in some animals.
Paroxetine should not be used in animals with known hypersensitivity or allergy to the drug.
The drug should be used with caution in elderly patients, patients with blood or kidney disorders, and patients with a history of seizures.
The drug should be discontinued in any patient that develops seizures while receiving treatment. If your pet experiences seizures while getting paroxetine, contact your veterinarian immediately.
Lack of appetite, lethargy, tremor, and increased thirst are the most common side effects of paroxetine.
Some pets may develop dry or itchy skin, vomiting, or diarrhea.
Paroxetine may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with paroxetine. Such drugs include MAO inhibitors (Anipryl®), cimetidine, phenytoin, and L-tryptophan.

Medication should never be administered without first consulting your veterinarian.
In dogs, the usual dose of Paroxetine is 0.5 to 1 mg per pound (1 to 2 mg/kg) orally every 24 hours.
In cats, the usual dose of Paroxetine is 0.25 to 0.75 mg per pound (0.5 to 1.5 mg/kg) orally every 24 hours.
The duration of administration depends on the condition being treated, response to the medication, and the development of any adverse effects. Be certain to complete the prescription unless specifically directed otherwise by your veterinarian.