Pain Management for Horses

Your veterinarian will help you determine what type of pain management protocol is best for your horse. Photo: Leslie Potter

Pain is a natural signal that lets us know when something is wrong. Without that trigger, we’d be apt to keep moving through an injury or illness, making it worse. When your horse is in pain, your first impulse is to do whatever it takes to help him feel better. But for his health and safety, it’s important to understand what is causing his discomfort and manage it accordingly.

Recognizing Pain
Signs of pain in horses can be quite subtle. A slight hitch in their gait or general lethargy can signal that something is wrong, but go unnoticed by caretakers.

“Pain can often be difficult to evaluate in equine patients,” says Lori A. Bidwell, DVM, DACVAA, a veterinary anesthesiologist and Assistant Professor at the Michigan State University College of Veterinary Medicine. “Some horses express pain by obvious non-weight bearing lameness and refusal to walk. Bucking or ‘girthiness’ are other less-than-subtle expressions of pain associated with back pain or lameness.

“Signs of abdominal pain include loss of appetite, rolling the upper lip, pawing or biting at their sides and violent rolling as an extreme expression of pain.”

The best way to recognize symptoms of pain is to know your horse’s normal behavior. For example, some horses take frequent naps while others almost never lie down. Lying down is only cause for concern if it is outside the horse’s usual behavior patterns.

Managing Pain
“There used to be a thought process that pain was useful in preventing a horse from re-injuring a limb by overuse, so pain management was not administered,” explains Bidwell. “Research has determined that appropriate analgesics (painkillers) maintain appetite and minimize stresses that can alter metabolism. Some horses are sensitive to the negative effects of non-steroidal anti-inflammatory drugs (NSAIDs), therefore alternatives must be used. But treating pain is still a priority.”

If your horse is showing signs of severe pain or lameness, in most cases you should call your vet before administering any type of pain medication. Observing the nature of your horse’s pain will help your vet diagnose his injury or illness and treat it appropriately in a way that will reduce the risk of re-injury once the horse is no longer in pain.

“Drugs for pain management can mask pain that has a protective mechanism (a non-displaced limb fracture, for example),” says Bidwell. “Therefore, appropriate diagnosis is important prior to initiating a pain management protocol.”

Acute Pain
Pain that lasts a short time and usually occurs due to a sudden illness or injury is referred to as acute pain. In horses, this might be caused by straining a tendon or ligament, a kick from a pasturemate, or abdominal pain due to colic. The goal of managing this type of pain is to keep the horse comfortable while he recovers and minimize the risk of secondary health problems caused by the stress of pain.

“Drugs and treatments are different depending on the source of pain,” explains Bidwell. “Acute abdominal pain responds well to buscopan for gas-associated pain or flunixin meglumine (banamine), butorphanol and an alpha-2 adrenergic agonist (xylazine, detomidine or romifidine) for most general abdominal pain syndromes. Pain associated with joints, muscles and soft tissues responds to NSAIDs such as phenylbutazone (bute) and flunixin meglumine and opioids like butorphanol, morphine or methadone.”

Chronic Pain
Pain that persists for a long period of time without a single causal event is called chronic pain. This might be ongoing back pain or lameness or joint pain caused by arthritis. Some chronic conditions can be managed so that the horse can continue to be ridden safely. In other cases, the cause of the pain might prevent him from working, and the goal of treatment is to keep him reasonably comfortable in retirement.

“NSAIDs are very useful for chronic pain, but the negative side-effects like gastric ulcer or compromise of kidney blood flow can become concerning with long-term use in some horses,” says Bidwell. “Alternative treatments using gabapentin or low-dose aspirin combined with a source of omega-3 fatty acids, tramadol (a mild opioid) and methadone (a strong opioid) have been found to be useful for chronic joint or foot pain. Acupuncture and massage are very useful adjuncts for pain management.”

When dealing with a chronic condition, it is important to work with your vet to tailor the treatment to best suit your horse. Your options will vary based on your horse’s age, health history and your expectations. If you are willing and able to scale back your horse’s workload, your vet may be able to help come up with a more conservative approach to pain management that will be more sustainable in the long term.

“Long-term use of any drug can present concerns,” says Bidwell. “Anti-inflammatory drugs are very effective for pain management, but the risk of gastric ulceration and kidney damage can prevent their use in horses sensitive to these classes of drug. Opiods decrease gastric motility increasing the risk of gastric impaction and colic. Appropriate dosing can minimize these risks but not prevent them. Every horse responds differently to drugs and it is important to tailor a pain management program to each specific patient.”