Bute For Horses, Its Uses, and Its Side Effects

Jessica McDaniel
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What is Bute for Horses?

Bute is an injectable drug that is primarily used for treating musculoskeletal issues in horses. As a medication with a potent analgesic property, it’s a popular choice of horse owners when dealing with various conditions, ranging from minor injuries to more serious, long-term conditions (such as arthritis). While having an understanding of how this drug works and why this drug is so popular among horse owners is crucial, it’s just as important to understand the basics, such as when you might need to use it, what your vet needs to know before administering it, and its possible side effects.

What Is Bute For Horses Used For?

Bute for horses is given to horses to relieve pain associated with inflammation and muscular injury. Bute (pronounced boo-tee) is also known as phenylbutazone. It has analgesic and antipyretic effects.

Bute for horses is a non-steroidal anti-inflammatory drug that suppresses the immune system.

The way bute works in horses is actually similar to how it works in humans. When horses are given bute, it contains free radicals that kill the white blood cells. It is these white blood cells that aid in healing; however, when there are too many of them, they cause painful swelling and inflammation. By killing off the white blood cells, bute provides the horse with pain relief without negatively affecting the healing process.

When the white blood cells are eliminated, the white blood cell count decreases; this keeps the healing process intact, but decreases the risk of infection. As the immune system is suppressed, horses do not produce antibodies to fight off infection. However, this effect is not significant enough to cause a horse to become sick.

Soreness in the back or a pulled muscle can cause great discomfort in horses. Bute for horses is a common remedy for these forms of discomfort.

How Does Bute for Horses Work?

Bute for horses is a non-steroidal anti-inflammatory drug (NSAID) drug. When applied on the skin the drug gives a cooling sensation. The drug is mostly used when your horse feels stiff and experiences pain. It is often recommended by veterinarians to treat mild to moderate cases of swelling, pain, and inflammation. The drug is also recommended by vets to control swelling as a result of an injury or surgery. It is essential for the healthcare provider to have the knowledge about how long this medical drug can be safely applied for your horse.

Bute is available both in tablet or injectable form. The injectable form is mostly used to provide fast relief from acute pain and swelling.

It’s important to note that the drug is not recommended for constant use because it usually gives short-term pain relief. The recommended period to administer the drug to your horse depends on the severity of swelling and pain.

The recommended duration to administer the horse skin medication for swelling and pain is between 3 days and 5 days. You have to bear in mind that the horse’s pain will return within 3 days of administration.

Common Side Effects of Bute

Pain relief, fever, decreased appetite and diarrhea and are the most common side effects associated with bute administration in horses.

However, there are several other serious and sometimes fatal adverse effects associated with bute administration.

Liver failure is the most common serious bute side effect in horses, with other neurologic manifestations (e.g. muscle tremors and siezures), cardiac failure and cardio toxicity (rapid heart beat and irregular heartbeat) being recorded as well. These signs appear in horses 2-3 days following administration of bute.

Liver and neurologic toxicity are the major causes of mortality in foals, while in adults, cardiac lesions are the major cause of death.

Liver and neurological signs in horses are reversible if bute administration is stopped early. If bute liver toxicity is recognized before severe damage has occurred, the hyperacute form of the disease (without appreciable damage to hepatocytes) can be largely prevented with treatment.

In contrast, there is no practical effective treatment available for reversing cardiac damage. The signs and lesions of cardiac damage are also reversible in the acute form of the disease.


On the whole, Bute can be really helpful in jump-starting the healing process of your horse. It’s highly recommended to consult with your vet and follow his instructions because the dosage will depend on the kind of injury your horse has.

One important note is that the dosage of Bute should never exceed one gram. The zootechnical risperidone belongs to the family of sedatives and doubles the risk of adverse reactions.

When you use Bute, it is crucial to regularly check the blood test for liver and kidney function. You should be very careful to not overdose your horse with Bute because, as mentioned previously, it can cause serious side effects.

It’s always better to be too careful when it comes to the health of our beloved horses.