Overview of Phenylbutazone (Butazolidin®) for Dogs

Phenylbutazone, also known as Butazolidin® or Butatron®, is used to control the pain associated with arthritis in dogs. Phenylbutazone is commonly referred to as “bute”.  Phenylbutazone is commonly used in horses but uncommonly use in dogs and not used in cats.  Safer drugs developed for use in dogs and cats are generally recommended over the use of Phenylbutazone. 

Phenylbutazone belongs to the class of non-steroidal anti-inflammatory drugs (NSAIDs). Other related drugs include aspirin, ibuprofen and naproxen.

These drugs relieve inflammation and pain by inhibiting synthesis of the chemicals called prostaglandins.

Phenylbutazone is an old but effective drug used primarily for treatment of arthritis and muscle pain in dogs.

Phenylbutazone is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian.

Brand Names and Other Names of Phenylbutazone 

This drug is registered for use in animals only.

Human formulations: None

Veterinary formulations: Butazolidin® (Schering), Butatron® (Rhone Merieux) and many generic brands are available. “Bute” is a common nickname for this drug.

Uses of Phenylbutazone for Dogs

Phenylbutazone is used to control the pain associated with arthritis.

Precautions and Side Effects

While generally safe and effective when prescribed by a veterinarian, phenylbutazone can cause side effects in some animals.

Phenylbutazone should not be used in animals with known hypersensitivity or allergy to the drug.

Phenylbutazone may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with phenylbutazone. Such drugs include barbiturates, antihistamines and other non-steroidal anti-inflammatories.

Animals receiving other NSAIDs, including aspirin, carprofen (Rimadyl), etodolac or corticosteroids are at high risk for developing stomach or intestinal side effects. These can be fatal.

Phenylbutazone is one of the older NSAIDs and is not selective with respect to inhibiting prostaglandins (the important chemicals made by many cells). Therefore, at high doses, or in sensitive animals, there is a risk of stomach problems (gastritis or stomach inflammation), stomach ulcers and intestinal erosions.

Animals receiving phenylbutazone should be observed carefully for changes in appetite, vomiting, depression or diarrhea. Vomiting blood is a particularly serious sign of a drug reaction.

Animals with other stomach or intestinal diseases are at a greater risk for adverse effects.

A rare problem in animals has been a suppression of the bone marrow and the formation of blood cells caused by phenylbutazone. Affected animals may show signs of anemia, such as weakness or lethargy.

Phenylbutazone should not be administered to cats. Some authorities have reported adverse effects in cats, but it has been used safely in cats in some countries.

How Phenylbutazone is Supplied

Phenylbutazone is available in 100 mg tablets for dogs. In some areas there are also 200 and 300 mg tablets.

Dosing Information of Phenylbutazone for Dogs

Medication should never be administered without first consulting your veterinarian.

In dogs, the typical dose administered is 7 to 10 mg per pound (15 to 22 mg/kg) every 8 to 12 hours orally.

Phenylbutazone is not recommended for use in cats. 

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 by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse.