Horse joint health

Back pain is a common condition in horses, typically noticed by owners when horses begin to resent grooming or saddling, or perform poorly under saddle.

Lethargy describes lack of energy and enthusiasm that persists regardless of exercise and activity. Lethargic horses may seem sleepy or drowsy, hang their heads low, or show lack of interest in food, other horses, or their environment.

Caudal heel pain syndrome in horses (formerly known as navicular disease) is the degeneration of the navicular bone seen in conjunction with damage to various surrounding tendons, bursa, and ligaments.

Black walnut toxicosis is a severe condition that occurs when horses come into contact with black walnut shavings or ingest the bark, pollen, or leaves of the black walnut tree (Juglans nigra).

Potomac horse fever (PHF) is an intestinal infection caused by Neorickettsia risticii, a bacteria that is transmitted from a parasite affecting snails, to aquatic insects, and then ingested by the horse.

Equine protozoal myeloencephalitis (EPM) is a serious neurologic disease in horses caused by the infectious protozoan organism, Sarcocystic neurona (and rarely, Neospora hughesi).

Atrial fibrillation in horses is a cardiac arrhythmia where the atria (top of the heart) beat rapidly and out of synchronization with the rest of the heart. Causes of atrial fibrillation include heart disease, electrolyte imbalances, and colic.

Angular limb deformities (ALD) in foals are deformities of the limbs where the leg is not straight when viewed from the front or behind. This is usually due to one or more joints deviating inward or outward on the affected limb.

A horse which groans excessively or ‘roars’ during exercise may have laryngeal paralysis. This condition is caused by damage to a nerve inside the neck which controls the opening of the throat.

Recumbency describes a horse who is lying down, unable to rise. Recumbent horses are typically laying flat on their side, but some may be able to sit up on their chest. Recumbency may be caused by a wide variety of conditions, including injuries, degenerative diseases, inflammatory diseases, tumors, infectious diseases, toxicosis, and neurological conditions.

Swollen legs, sometimes referred to as “stocking up,” are a noticeable increase in the size of the legs, giving affected horses the appearance of a “fat leg”. If leg swelling is accompanied with pain, heat, or lameness, it requires emergency veterinary attention.

Oxalate toxicosis occurs when horses ingest a toxic dose of oxalates, which are naturally occurring acid compounds that can be found in a number of plant species. Once ingested, the oxalate acids bind to calcium in food sources, preventing absorption of calcium by the body. 

Black locust poisoning is a potentially life-threatening condition in horses, resulting from the ingestion of the seeds, leaves, or inner bark of the black locust tree. Symptoms of black locust toxicosis generally present within two hours of ingestion and include abdominal pain, diarrhea, blood in feces, and dilated pupils.

Selenium (Se) is a micronutrient mineral that, in small doses, plays an essential role in a healthy diet in horses. Selenium poisoning is a potentially life-threatening condition that occurs when an excessive amount of selenium is ingested.

Yellow star thistle poisoning, also called nigropallidal encephalomalacia or “chewing disease”, occurs when a horse eats a toxic amount of the yellow star thistle plant. Yellow star thistle is an annual weed commonly found in western North America, the Mediterranean, Argentina, and Australia. 

Monensin poisoning occurs when horses ingest a toxic dose of monensin, an antibiotic commonly used as a feed additive to promote cattle and poultry growth. Monensin is highly toxic to horses and commonly fatal.

Muscle twitching and cramping, also referred to as “tying up”, are symptoms that appear from painful and continuous muscular contractions. During a severe episode, horses might refuse to move and suffer from extreme pain.

Spinal disorders are a group of conditions that affect the bones, muscles, ligaments, nerves, and other structures of the back in horses. Spinal disorders are most common in horses involved in heavy sport and competition.

Equine metabolic syndrome (EMS) occurs when insulin levels are consistently high, leading to dysfunction of the systems that regulate body fat and blood sugar. EMS is caused by a combination of genetic predisposition and environmental factors, such as high-sugar diets and obesity, although it is unclear why some horses develop this condition and others do not.

Osteoarthritis is a progressive disease resulting in damage to the joint cartilage and underlying bone. Arthritic damage causes significant pain, and typically results in lameness, limited mobility, joint swelling, and poor performance.

Laminitis refers to inflammation of the lamellae, the support structure that holds the coffin bone in place within the hoof capsule. The lamellae are extremely sensitive, making laminitis a very painful condition.

Joint infections are infections found in the joints of horses which cause pain, inflammation, fever, and lameness. Joint infections are always an emergency and require immediate medical assistance.

Fetlock arthritis (aka “osselets”) in horses is inflammation of the fetlock joint and surrounding tissues. This condition is common in performance and racehorses.

Exercise intolerance is the decreased ability to tolerate strenuous exercise. Exercise intolerance is one of the first signs of exhaustion

Limited mobility (LM) in horses is defined as a reduction in agility and/or movement, and is a condition that mainly affects senior and geriatric horses (over 18 years of age).

Bone spavin in horses is painful, progressive, irreversible osteoarthritis of the lower hock joints.

“Ringbone” refers to ring-shaped bony protrusions formed due to osteoarthritis in either the pastern joint or coffin joint in horses.

Joint swelling is a common symptom in horses and has a variety of causes.

Tick paralysis results when a tick’s saliva delivers a paralytic toxin into the bloodstream of its host. Equine tick paralysis is rare, as horses seem to be resistant to most tick toxins.

Lyme disease is caused by the tick-borne bacteria *Borrelia burgdorferi*. Horses become infected with the bacteria when an infected tick feeds on them.