Pain is something that all horses deal with at some point in their lives. Horses can experience pain for many different reasons, including injury, illness, or a result of surgery.

For example, castration is the most common surgical procedure performed on horses and is associated with significant post-operative pain.

Acute colic is another common painful experience for horses. [3] Pain is also commonly associated with degenerative joint disease, laminitis, gastric ulcers, and hoof issues.

Unlike humans, horses don’t always show it when they are experiencing pain, or they may only display subtle signs of discomfort. This is because, as prey animals, they have evolved to hide signs of pain and weakness in the presence of predators. [2]

As horse owners, we want to know how to alleviate pain for our horses. Pain management strategies will be different for every horse, depending on what’s causing the pain, the severity and duration of the pain, as well as the horse’s intended work.

Understanding Pain in Horses

While we may think of pain as bad, pain is an important feedback mechanism to help horses survive in their environment.

A basic bodily sensation brought about by noxious (harmful) stimulus, pain is associated with actual or potential tissue damage or nerve injury. Pain is a signal received by nerve endings and can be viewed as an internal warning system. [1]

Pain needs to be proactively managed. Anxiety and stress can enhance pain perception in horses and vice versa. [4]

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Adaptive vs. Maladaptive Pain

When pain serves a purpose – such as to protect an injured area or to promote healing and recovery – it is referred to as adaptive pain. [4]

Horses can also experience pain due to necessary veterinary interventions such as surgery. Navicular syndrome, laminitis, and osteoarthritis can cause chronic (long-term) pain.

Both surgery and chronic, painful conditions lead to maladaptive pain. This form of pain is dysfunctional: it neither protects nor supports the healing and repair of bodily tissues. [4]

The goal of pain management is to eliminate maladaptive pain for our horses while keeping the adaptive component. It is important for veterinarians and horse owners to recognize the differences between adaptive and maladaptive aspects of pain. [4]

Classifying Pain

Traditionally, pain in horses is classified according to the following factors:

  • Duration: acute (short-term) or chronic (long-term)
  • Anatomic location: superficial, deep, visceral (related to the internal organs), or musculoskeletal
  • Quality: dull, sharp, burning, stabbing, throbbing, persistent or recurrent
  • Intensity: mild, moderate, severe, excruciating, crippling [4]

The above classifications are descriptive, but they do not always provide enough information to inform a treatment approach. A new classification has been added in recent years to identify three main types of pain:

1. Nociceptive Pain

This type of pain is caused by damage to bodily tissue, often from an external injury. Nociceptive pain includes a behavioural response characterized by a motor withdrawal reflex or more complex behaviours.

When associated with veterinary intervention, nociceptive pain is usually not chronic or permanent. Nociception can occur without pain, such as with general anesthesia for surgical treatment. [1][4]

2. Inflammatory Pain

Inflammatory pain is produced by the activation of nerve-ending cells called nociceptors. Nerve endings then secrete inflammatory molecules in a process called neurogenic inflammation.

This type of pain is an adaptive response that encourages a decrease in mobility until the tissue heals. [4]

Inflammatory pain sometimes leads to changes that result in spontaneous and excessive pain. In this case, it becomes maladaptive and needs to be managed. [4]

3. Neuropathic Pain

This type of pain results from dysfunction or damage to the peripheral nerves and spinal cord / central nervous system. It is often secondary to trauma or chronic inflammatory diseases and has no apparent protective or reparative function.

Neuropathic pain is maladaptive and needs to be controlled. Equine conditions such as head shaking, chronic laminitis, and nerve damage during surgery can be associated with neuropathic changes and pain. [4]

Acute vs. Chronic Pain in Horses

Acute pain is short-term pain that generally follows an injury. Heat, swelling, redness, and loss of function may occur as the body tries to remove injured or damaged cells, eliminate foreign material, minimize further damage, and allow tissue regeneration.

The goal of managing an acute injury is to limit the inflammatory response and reduce immediate discomfort. [5]

Chronic pain, however, lasts for a longer period of time. It is considered maladaptive when it persists beyond the expected period of tissue healing.

Chronic pain is complex, with both inflammatory and neuropathic events involved and affecting nerve pathways that supply the diseased area. [5][6]

Equine Pain Measurement Scales

In the past, veterinarians evaluated pain in horses based on objective measurements such as heart and respiratory rate. They also sometimes use endocrine measures such as circulating levels of cortisol.

However, these measurements cannot definitively show a horse is experiencing pain; they only indicate physiological or psychological stress. [2][3]

Researchers have recently developed several pain measurement scales that give a clearer indication of pain in horses.

Effective pain measurement scales are easy to use, apply to most horses and situations, and provide consistent results. Pain scales must also be sensitive enough to differentiate between mild, moderate, and severe pain. [3]

Horse Grimace Scale

The Horse Grimace Scale is an evaluation tool that determines a horse’s pain by examining facial expressions.

This scale includes detailed descriptions and photographs to illustrate various expressions associated with different levels of discomfort in horses. [2]

Facial expressions most frequently associated with pain include: [5]

  • Low and/or asymmetrical ear positioning
  • Angled appearance of the eyes
  • A withdrawn or tense stare
  • Dilated nostrils
  • Tension in jaw, chin, lips or other facial muscles

Obel Laminitis Pain Scale

The Obel laminitis pain scale is widely used in horses with laminitis and classifies the severity of lameness by grade from I to IV.

This scale also includes behaviours such as weight shifting, resistance to having limbs lifted, and disability. [3]

A modified Obel scale has been developed for use in the research setting for horses with endocrinopathic laminitis. [32]

AAEP Lameness Grading Scale

The American Association of Equine Veterinarians (AAEP) lameness grading scale is also commonly used by veterinarians because it is simple and more repeatable than many other lameness scales. [5]

The scale ranges from 0 – 5, with 0 indicating no lameness and 5 indicating extreme lameness. [27]

  • Grade 0: Lameness is not perceptible under any circumstances; manipulating the limbs does not produce gait abnormalities.
  • Grade 1: Lameness is difficult to observe and is not consistently apparent regardless of circumstances.
  • Grade 2: Lameness is difficult to observe at a walk or trot in a straight line but consistently apparent in certain circumstances.
  • Grade 3: Lameness is observable at a trot under all circumstances.
  • Grade 4: Lameness is obvious at a walk.
  • Grade 5: Lameness produces a complete inability to bear weight or a complete inability to move.

Flexion Test

Veterinarians also use functional tests, such as the flexion test in a lameness evaluation.

This particular test evaluates the amount of flexion in a joint, the duration the flexion is tolerated, exaggeration in lameness when trotting off after the flexion test, as well as the response to increased weight bearing on the stance limb. [5]

Limitations of Pain Scales

Though pain scoring systems can help you and your veterinarian determine whether your horse is experiencing pain, a number of factors limit the value of these scales in clinical practice.

For example, extended observation periods are usually infeasible in a clinical setting. Also, the veterinarian’s physical proximity may affect the horse’s behaviour.

Other factors, such as time of day, anesthesia, or the administration of pain medications before the assessment, can affect pain behaviours as well. [7]

In one study, researchers found that many ongoing discomfort behaviours in horses lessened or stopped during caretaker visits for pain assessments. Cameras showed that these behaviours resumed once the caretakers left. [2]

You may need to observe your horse without them knowing it to identify signs of pain, especially if chronic pain is suspected.

Signs of Pain in Horses

Though many signs of pain in horses are subtle or non-specific, other signs may be more obvious, especially when pain is ongoing or substantial.

The following are general behavioral signs of pain:

  • pawing
  • stamping
  • tail-swishing (without insects)
  • circling in stall
  • flaring nostrils repeatedly
  • repetitive behaviours such as rubbing or pacing
  • getting up and laying down frequently
  • rocking back and forth on limbs
  • grunting

Several musculo-skeletal signs of pain include:

  • frequent weight shifting
  • rocking back and forth on limbs
  • stamping
  • grimacing
  • localized muscle tension (splinting)
  • limping, head bobbing
  • shortened stride length
  • less spontaneous movement in general, less trotting or cantering
  • resistance to move forward when ridden or led
  • bucking

Some signs of abdominal pain (i.e. due to colic or ulcers) include:

  • pawing
  • flank watching or biting
  • teeth grinding
  • kicking at abdomen
  • rolling
  • grunting
  • thrashing

If a horse is experiencing pain in a certain location on their body, they may react in the following ways upon palpation of the area:

  • muscle twitching
  • splinting
  • hyperalgesia/allodynia
  • biting
  • striking
  • kicking [8]

Other indicators of pain can include lowered or flattened ears, standing with the head in a low position, or altered eating or drinking. [9]

Pharmacologic Pain Management for Horses

Pharmacologic pain treatment should be discussed with your veterinarian and tailored to the severity and type of pain the horse is experiencing.

Most medications used to treat pain in horses fall into one of four broad categories: [1]

  • Steroidal and non-steroidal anti-inflammatories drugs (NSAIDs)
  • Opioids
  • Alpha-2 agonists
  • Local anesthetics

Corticosteroids

Corticosteroids (more specifically known as glucocorticoids) are a group of potent anti-inflammatory and immunosuppressive drugs often prescribed by veterinarians.

The most commonly used corticosteroids prescribed for horses are: [ ref n=”10″]

  • prednilosone
  • dexamethasone
  • triamcinolone acetonide

Corticosteroids are often given for immune-related diseases such as asthma and vasculitis. They are also used as short-term anti-inflammatory treatment and to decrease tissue swelling for surgeries, such as throat surgery.

These medicines may also be used to decrease inflammation and fever in life-threatening inflammatory diseases, such as meningitis or acute lymphangitis. [10]

Corticosteroids can also be injected into the joint as a treatment for osteoarthritis or used topically for painful eye conditions such as conjunctivitis or uveitis. [10]

However, this group of drugs can have adverse effects, including bacterial or fungal infection, decreased wound healing, and insulin-resistant laminitis.

Less severe adverse effects include muscle wasting, high blood sugar, and increased thirst and/or urination. Because of the risk of side effects, corticosteroids should not be used long-term in most cases. [10]

Non-Steroidal Anti-inflammatories

Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) are the most commonly prescribed drugs for equine pain management. These medications have anti-inflammatory and analgesic (pain-relieving) properties and work by blocking cyclooxygenase (COX) enzymes.

COX enzymes are used by the horse’s body to make immune compounds called prostaglandins. These compounds are produced at the specific area of tissue damage or infection and help with healing processes such as inflammation, blood flow, and blood clotting.

When cyclooxygenase is blocked, there is a reduction in these processes. As a result, NSAIDs can relieve discomfort caused by fever and reduce associated inflammation and pain.

NSAIDs are often used for inflammatory conditions such as myositis, tendonitis, laminitis, osteoarthritis, and surgical trauma. They are also often given intravenously before or during anesthesia to reduce pain during and after surgery. [11]

NSAIDs for Horses

The most commonly prescribed equine NSAIDs include:

  • Phenylbutazone (Bute)
  • Flunixin meglumine (Banamine)
  • Diclofenac sodium (Surpass)
  • Ketoprofen (Ketofen)
  • Firocoxib (Equioxx, Previcox)
  • Meloxicam

COX-2 Selective NSAIDs

There are two classes of NSAIDs: those that block COX-1 and COX-2 enzymes and those that only block COX-2 enzymes.

COX-1 and COX-2 enzymes both produce prostaglandins that promote inflammation, pain, and fever, but only COX-1 enzymes activate blood platelets and protect the stomach and intestinal wall.

Traditional NSAIDs such as Bute and Banamine are nonselective COX inhibitors. Because of this, their long-term use can cause damage to the gastrointestinal tract, including causing gastric ulcers and right dorsal colitis as well as kidney damage.

COX-2 selective NSAIDs such as Firocoxib are often used to control pain and inflammation associated with equine osteoarthritis.

These drugs are effective, and they have a lower risk of gastric ulceration than nonselective NSAIDs when used as directed. One study showed that 70% of horses with lameness improved after seven days of receiving Firocoxib. [6]

Precautions

Avoid long-term use of NSAIDs unless under the supervision of a veterinarian.

Nonselective NSAIDs can cause others side effects, such as impairing kidney function or causing bleeding disorders. Out of phenylbutazone, flunixin, and ketoprofen, phenylbutazone had the greatest toxic potential, and ketoprofen had the least toxic potential. [11]

Horses receiving NSAIDs for a prolonged period should be continually monitored for total protein and creatinine levels in their blood to detect possible adverse reactions. [12]

NSAIDs should not be used at the same time as SGLT2 inhibitors for metabolic syndrome because of an increased risk of kidney damage. [34]

Phenylbutazone should never be given by intramuscular injection due to the risk of caustic tissue reactions. Antibiotics such as chloramphenicol and rifampin should not be given in conjunction with phenylbutazone due to potential drug interactions. [11]

The combination of phenylbutazone and omeprazole will decrease the risk of gastric ulcers but increases protein loss through right dorsal colitis. [33]

Opioids

Although more effective and with fewer side effect concerns than NSAIDs, opioids are more common in the hospital setting than in general practice because of rigid regulatory requirements.

Opioids have been used as pain-relieving drugs in horses for at least 70 years. However, their use requires caution due to a risk of decreased gastrointestinal motility with long-term use. [13]

Butorphanol is the most commonly used opioid for horses, especially for visceral pain. Morphine is sometimes used during surgery, but it poses a risk of post-operative colic. [12]

Other opioids used for horses include the fentanyl transdermal patch and tramadol, prescribed to help manage pain in horses with chronic laminitis. [4][14]

Alpha-2 Agonists

Alpha-2 agonists are potent sedative drugs that have been found to decrease pain. These drugs include:

  • xylazine
  • clonidine
  • detomidine
  • medetomidine
  • dexmedetomidine

Due to their sedative, musculoskeletal, and physiologic effects, alpha-2 agonist drugs should only be used by veterinarians in a clinical or surgical setting. [5]

Local Anesthetics

Local anesthetics are medications that can be applied topically or injected at a specific site on the body to alleviate pain. Medications include:

  • lidocaine
  • mepivicaine
  • bupivicaine
  • ropivicaine

Local anesthetics affect a horse’s peripheral sensory nerves to reduce pain sensations. These drugs work by blocking sodium ion channels on nerve cells. [1][11]

Negative side effects of local anesthetics can occur if there is inadvertent intravenous injection. These include nervous system excitation or depression, which may result in pawing, circling, or pacing. Other side effects include muscle tremors, incoordination, and convulsions. [11]

To reduce this risk veterinarians draw back on the syringe plunger to ensure they are not in a blood vessel before injecting local anesthetics.

Other Pain-Relieving Drugs for Horses

Novel drugs are being developed and tested for both acute and chronic pain in horses. One such pharmaceutical is gabapentin, an anti-seizure drug with pain-relieving effects.

Polysulfated glycosaminoglycans (PSGAGs) are used for the treatment of joint-associated pain. PSGAGs are given either through intramuscular or intra-articular injection.

Studies show that PSGAGs decrease inflammatory mediators and up-regulate collagen synthesis in joints, often improving lameness scores. [5]

Butylscopolamine is sometimes used to treat spasmodic colic.

Dipyrone (metamizole) is an anti-inflammatory drug used to treat mild visceral pain in a clinical setting

The biphosphonates tiludronate and clodronate are given either intravenously or intramuscularly to limit bone resorption and improve lameness from arthritis and navicular syndrome. [15]

Pain-Relieving Herbs for Horses

Sarapin is an extract of the Pitcher plant used to treat muscle pain associated with the spine and sacroiliac joints. [1][5]

Harpagophytum procumbens, commonly known as Devil’s Claw, is a time-honored anti-inflammatory and analgesic herbal medicine. It acts at the level of gene expression to support the normal homeostatic regulation of inflammation. [36]

It was found to be as effective as phenylbutazone in tarsal arthritis. [37] Despite being classified as a “bitter” which stimulates stomach acid secretion, no effect on gastric ulcer score has been found. [38]

Pain Management After Surgery

Surgical intervention is sometimes necessary to address equine conditions or injuries. In the past, some thought that pain-relieving medications should be withheld from horses to maintain their protective reflexes and reduce the risk of injury.

However, pain control after surgery has become standard to avoid delayed recovery caused by acute pain. [16] In orthopedic surgery, pain management is vital to decrease stress and recovery time for the horse while providing maximum comfort. [11]

The NSAID meloxicam is widely used for pain management before and after surgery. [16]

Local anesthetics can be helpful but should be used with care after orthopedic surgery as they may cause loss of proprioception and feeling. This could lead to injury during the recovery process. [11]

Non-Pharmacologic Pain Management for Horses

Many non-medicinal pain management treatments can also help address acute and chronic pain in horses. Treatment methods include acupuncture, chiropractic, massage, therapeutic exercise and other bodywork forms.

These therapies can often be used in conjunction with pharmacologic pain management.

Acupuncture

Acupuncture is a form of Traditional Chinese Medicine that has been around for centuries. The modality has gained popularity in the U.S. in recent decades and is used with both people and animals.

Acupuncturists insert small, non-painful needles at specific points called acupoints on the body. Acupoints are specifically chosen depending on the horse’s individual symptoms.

Studies show that acupuncture can help to reduce nociceptive pain, especially in horses experiencing musculoskeletal pain. [4] Acupuncture increases the concentration of natural opioids found in blood plasma and cerebrospinal fluid, producing a pain-relieving effect. [5]

Electroacupuncture is a variation of acupuncture in which a small electric current is passed between pairs of acupuncture needles. Studies show that it can help resolve chronic back pain in horses. [5]

Chiropractic

The goal of chiropractic adjustment is to alleviate pain through proprioceptive and motor muscle retraining.

Treatment is characterized by high-velocity, low-amplitude manual thrusts on the horse’s spine aimed at restoring normal joint motion and improving tissue function. [5][14]

One study showed that chiropractic treatment increased mechanical nociceptive thresholds by 27% for up to 7 days. [5]

Another study concluded that chiropractic manipulations increased flexion and extension range of motion in horses at a trot one hour after treatment. [18]

Massage

Massage involves the manipulation of tissues by rubbing, kneading, or tapping.

Limited research exists on equine massage, but studies show an increased mechanical nociceptive threshold in the spinal region and improved stride lengths at a walk and trot after massage. [5]

Soft tissue manipulation improves blood flow, which may reduce pain associated with tissue damage. Massage also triggers the release of endorphins and serotonin, which can alter pain perception. [5]

Therapeutic Exercise

Light exercises such as hand walking, walking over poles, backing, and hill work can have a healing effect on the soft tissues and bones. [5]

Always check with your veterinarian to see if therapeutic exercise is safe for your horse. It may be contraindicated in some cases, such as directly after surgery or following a severe injury.

Hydrotherapy

Aquatic therapies are reported to reduce pain in human studies, and this modality may also benefit horses.

Specialized facilities enable horses to swim in pools or exercise on an underwater treadmill. Exercising in water helps to reduce the effects of gravity on the horse’s body, reducing stress on bones, joints, ligaments, and tendons.

Applying or soaking your horse’s limbs in warm water can help improve circulation and reduce muscle spasms.

Cryotherapy

Cryotherapy involves using ice packs, boots, cold water or other specialized products on parts of the horse’s body. Cryotherapy is most helpful when applied immediately after an injury and reapplied every 2-4 hours afterward.

Cold therapy provides pain relief to the specific area, reduces inflammation, and helps to protect injured cells. Cryotherapy can be especially helpful for horses experiencing acute laminitis related to a systemic inflammatory response. [5]

Low-level laser therapy

Low-level laser therapy uses a non-invasive light source that generates a single wavelength of light. This type of therapy has been shown to reduce pain in human osteoarthritis patients, and it is commonly used on horses.

Low-level laser therapy is thought to relieve pain in horses with osteoarthritis by inhibiting inflammation of the joint capsule. [5] Low-level lasers are also reported to have beneficial effects on musculoskeletal pain and are especially helpful with tendon and ligament issues. [15]

Extracorporeal Shockwave Therapy

Extracorporeal shockwave therapy uses focused, pulsed high-energy waves applied to an injured area. This therapy is used to treat a variety of musculoskeletal injuries in horses.

Studies show that shockwave therapy can relieve pain in horses with osteoarthritis. Initial pain-relieving effects lasted 2-3 days, but overall improvements in lameness score were seen 14 days after treatment. [5]

In human studies, extracorporeal shockwave therapy is effective for reducing pain and improving healing for chronic plantar fasciitis and chronic low back pain.

Though researchers aren’t exactly sure why this therapy works, they believe it encourages new blood vessel growth and tissue remodelling in damaged tendons, ligaments, and bones. [5][15]

Electrotherapy

Electrotherapy relieves pain by transducing electrical current into the body to depolarize sensory neurons.

This therapy significantly improves chronic pain in humans. Electrotherapy is used on horses as well, and a review article summarizing various modalities in horses has been published. [35]

Therapeutic Ultrasound

Ultrasound devices use short bursts or continuous waves to deliver ultrasonic energy to bodily tissues. Therapeutic ultrasound can help to improve local circulation, increase cell membrane permeability, and reduce muscle spasms in injured tissue.

This therapy is gaining popularity in the equine industry. Evidence from human and small animal studies is used to support its effects. [5]

Kinesio-taping

Kinesio-taping is commonly used in equine and human sports medicine, but little research is available to evaluate it efficacy in horses.

It is thought that taping may release pressure on tissues from the skin and increase the movement of lymphatic fluid. [5]

Capsaicin Topical Products

Capsaicin is a natural compound that gives chilli peppers their spicy taste. When applied as a topical agent, it can help block pain signalling to the nerves.

Studies in humans show that capsaicin can help relieve pain from conditions such as osteoarthritis, fibromyalgia, muscle sprains and strains, migraines, and even surgical trauma.

In horses, one study concluded that topical application of capsaicin ointment over the palmar digital nerves in horses with laminitis provided measurable pain relief for up to four hours after treatment. [17]

Nutraceuticals for Managing Pain in Horses

Nutraceuticals are nutritional supplements or natural compounds that provide a physiological benefit. They are available without a prescription and are commonly used by horse owners, especially for chronic conditions.

Several different neutraceuticals have been studied for their effects on pain management and inflammation in horses, with varying degrees of efficacy.

Glucosamine and Chondroitin Sulfate

Glucosamine and chondroitin sulfate are natural components of articular cartilage – a strong, flexible connective tissue found in joints.

A combination of glucosamine and chondroitin is commonly used for osteoarthritis pain in horses. [19] However, research results have been mixed, with some studies showing a benefit and others showing no significant improvement in horses with joint disease. [20] They are most likely to be helpful in early cases and before extensive cartilage loss and bony change has occurred.

Methylsulfonylmethane

Methylsulfonylmethane, referred to as MSM, is another popular nutraceutical used for horses with joint pain. This ingredient is a sulfur-containing compound found naturally in your horse’s body, as well as in fresh forage and grains.

MSM has been shown to relieve arthritic pain and sore muscles and also protect against oxidative stress. [21][30]

MSM

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Green-lipped mussels

Green-lipped mussel (Perna canaliculus) is a source of glucosamine, chondroitin, omega-3’s and the protein pernin.

This ingredient shows effectiveness in improving lameness scores in horses with primary fetlock lameness. [19]

Omega-3 Fatty Acids

The omega-3 fatty acids, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) are found in algae and marine oils. These anti-inflammatory compounds have been shown to improve joint pain and reduce arthritic markers. [28]

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  • Helps to fight inflammation
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  • Palatable source of Omega-3's

Hyaluronic Acid

Hyaluronic acid (HLA) is a natural component of connective tissue and synovial fluid in the joints. Supplementing with HLA has been shown to improve markers of joint health and decreasing joint swelling. [29][31]

Cannabinoids

Cannabis is an herb from the Cannabaceae or hemp family of plants. Cannabis sativa L. is used to make cannabidiol (CBD) oils and other products.

Cannibis and cannabidiol (CBD) are among the fastest growing products in both human and veterinary medicine. [22][23]

CBD has been studied since the early 2000s as a treatment for inflammation, pain, epilepsy, and other diseases in human.

The equine industry is still in the early stages of investigating the effects of CBD. However, one study showed that CBD may help reduce chronic, low-grade inflammation that naturally occurs as horses age. [22][23]

It’s important to note that CBD and other cannabis-derived products have been banned by the Federation Equestrian International (FEI). Therefore, these products should not be given to competition horses. [23]

Check with your veterinarian to see if other supplement ingredients are safe for use in competition horses.

Pain Management for Chronic Equine Conditions

Unfortunately, many horses deal with ongoing pain due to a chronic condition. Below are some of the most common painful chronic conditions seen in horses and tips for their management.

Osteoarthritis

Most lameness issues in older horses are due to degenerative joint disease, also known as osteoarthritis (OA). Equine OA is characterized by a deterioration of the articular cartilage accompanied by changes in bone and soft tissues of the joint. [19]

Pain is one of the most common symptoms of arthritis in humans and is assumed to also affect horses. Pain in the synovial joints can originate from either mechanical changes in the joint itself (such as from trauma) or through chemical stimuli caused by inflammation. [19]

Synovitis can contribute to pain through joint effusion, swelling, and/or fibrosis.

Managing Osteoarthritis

For performance horses, osteoarthritis management should focus on bringing the animal back to competition. In older horses, however, the goal is to make the horse as comfortable as possible. [19]

Osteoarthritis can be treated locally at the affected joint(s) with overall pain management and/or with supportive treatments such as hoof care/farriery, physiotherapy, and exercise management. Treatment often involves a combination of all of the above. [19]

Intra-articular treatments for equine arthritis have become popular, especially with new therapies such as polyacrylamide gel, stem cells, platelet-rich plasma, and autologous conditioned serum. These treatments are injected directly into the affected joints.

Intra-articular corticosteroids are often used to treat OA flare-ups but chronic use is associated with loss of cartilage.

Hyaluronan (hyaluronic acid/HA) and polysulfated glycosaminoglycan (PSGAG) are also commonly used in treating equine OA either given systemically or intra-articularly. [19]

Tips for managing horses with OA include:

  • Treat every flare-up directly with either pharmaceuticals or Devil’s Claw.
  • When not an issue for horses in competition, topical capsaicin or Arnica montanum are effective.
  • Work to reduce horse’s weight, if needed. [4][19]
  • Use soft bedding in stalls.
  • Whether barefoot or shod, be sure the horse has a correctly balanced foot and receives regular hoof care.

Older arthritic horses may be affected by cold weather despite being comfortable in warm weather. This is because tissues become less flexible with age and cold increases tissue stiffness. [39]

Use warm wraps to help relieve the fetlock joints, tendons and ligaments. Neoprene wraps for carpi and hocks overnight are very effective in trapping heat.

Read additional tips on supporting your horse’s joint health in this article.

Laminitis

Controlling pain in horses with chronic laminitis is one of the most challenging problems facing horse owners and equine veterinarians today.

The most common treatment of laminitis-related pain is NSAIDs. Although higher doses of NSAIDs may be needed to keep the horse comfortable in the in the early stages of laminitis, the use of these drugs should be balanced against possible side effects and the risk of further injury due to excessive movement and limb loading. [11][13]

A popular approach in treating pain caused by laminitis is to combine NSAIDs, opioids and/or infusions of a2-agonists, ketamine, and lidocaine. Recent research also indicates that using amitriptyline and soluble epoxide hydrolase inhibitors might be beneficial. [4][13]

A newer anti-inflammatory and pain-relieving medication, a soluble epoxide hydrolase inhibitor, has also shown promising results in treating laminitis pain. [13]

However, none of these approaches is very effective with the most common cause of laminitis – hyperinsulinemia in EMS or PPID. This is because inflammation is not the root cause and only present to clean up damaged tissue. While NSAIDs or Devil’s Claw are reasonable for the first few days, only controlling insulin and a correct realigning trim will achieve pain relief.

Horses suspected of having PPID should be put on pergolide while awaiting laboratory results.

Horses suspected of having either PPID and EMS should be put on a diet of soaked grass hay only with metformin 30 mg per kg of body weight twice daily.

Horses with metabolic laminitis have increased levels of the potent vasoconstrictor endothelin-1. [41] The action of endothelin-1 is naturally counteracted in the vessels by nitric oxide production. The production of nitric oxide can be enhanced by feeding the herb Gynostemma pentaphylum (Jiaogulan). [42]

Managing Laminitis

Tips for managing horses with laminitis include:

  • For horses with PPID, treat primary cause with pergolide.
  • Give metformin at a dose of 30 mg per kg body weight twice a day for rapid insulin control when PPID or EMS suspected.
  • Discontinue NSAIDs after 3 to 5 days.
  • Put acutely laminitic horses on stall rest to prevent further damage to lamellae.
  • Adjust the horse’s diet by removing concentrates, fresh grass and silage. Provide only soaked hay and a concentrated vitamin/mineral supplement.
  • Perform a realigning trim as guided by radiographs.
  • Remove shoes if possible; reduce toe length and dorsal hoof wall.
  • Consider Jiaogulan supplementation for improved circulation in the feet.

Navicular Syndrome

Navicular syndrome, sometimes called caudal heel pain, has multiple components and symptoms that vary from horse to horse. However, this synrome is characterized by pain at the back of the foot and lameness. [24]

Horses with navicular syndrome may have changes to the navicular bone and other structures within the hoof. [24] Because of this, navicular syndrome is not always a straightforward diagnosis.

Managing Navicular Syndrome

This condition is often treated by injecting the coffin joint and/or navicular bursa with corticosteroids to reduce inflammation. Long-term pain management with COX-2 inhibiting NSAIDs such as Equioxx or with bisphosphonate such as osphos and/or tiludronate is also common. [4][24] However, no NSAIDs are
approved for long term use. Instead consider using Devil’s Claw which is safer.

A surgical procedure known as neurectomy, which cuts the heel nerves, is used as a last resort to alleviate pain in severely affected horses. However, postoperative complications are common with this surgery. [25]

Navicular syndrome can be a frustrating condition to treat because there is no one-size-fits-all approach to treatment. However, several tips for managing navicular syndrome in horses include:

  • Consider therapeutic shoeing or trimming (and possibly hoof boots) to provide balance and comfort. A balanced foot properly placed under the body is best.
  • Work with your veterinarian to find a treatment that works best for your horse.
  • Use Devil’s Claw or NSAIDs for acute flare-ups. [24]

Conclusion

Equine pain management should focus on preventing pain as much as possible. With many conditions, treatment may employ both pharmocologic and non-pharmocologic strategies for reducing pain.

Always work with your veterinarian to come up with an appropriate pain management plan for your horse and continually monitor your horse for signs of pain, especially when a chronic issue is present. [4]

If pain cannot be effectively managed and is a significant source of severe discomfort for your horse, it may be time to consider humane euthanasia.

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