Risks of giving intramuscular Banamine to horses

What is Banamine?

Banamine is a nonsteroidal anti-inflammatory agent that relieves pain, swelling and fever in horses.

Banamine comes in two forms: injectable and oral. Veterinarians routinely use the injectable form in the vein (IV). Horse owners may have oral and injectable Banamine on hand to relieve pain. Owners must know the risks of giving Banamine or other medications in the muscle (IM).

Muscle damage

Many drugs can cause muscle damage when injected:

• Banamine
• Ivermectin
• Progesterone
• Anti-histamines
• Phenylbutazone
• Dipyrone
• Vitamin B complex
• Synthetic prostaglandins

This usually does not cause problems. But spores of bacteria (Clostridium) can rest in healthy muscle and start to grow if the muscle gets damaged. This growth can cause Clostridial myositis, a serious and sometimes fatal infection.

Signs of Clostridial myositis infection

• Swollen and crunchy areas of gas under the skin at the site of IM injection.
  • This occurs within 6 to 72 hours from the start of bacterial infection.
• As bacterial toxins go into the bloodstream, horses quickly become very ill with signs of:
  • Depression
  • Colic
  • Purple gums
  • Not wanting to move

Diagnosing

Veterinarians can diagnose Clostridial myositis by:

• Identifying gas from Clostridia in the damaged muscle through ultrasound
• Examining fluid for bacteria

Treatment

It’s important to catch and treat Clostridial myositis early and aggressively to decrease deaths.

Affected horses benefit from hospitalization and intensive support with intravenous and oral antibiotics, as well as supportive care with anti-inflammatories and fluids.

Between 31 and 73 percent of horses survive Clostridial myositis but it may take months for the skin and muscle to heal.

Prevention

The risks of Clostridial myositis are relatively low. If possible, always give Banamine by mouth or have your veterinarian give the drug IV.

If you give any IM injection, watch

• The area for signs of swelling and gas pockets under the skin
• The horse for fever or depression

Call your veterinarian right away if you notice these signs.