Conditions

A heart arrhythmia, or irregular heartbeat, is a performance-limiting condition commonly seen in athletic horses. While some arrhythmias are benign, others may indicate cardiac disease or another underlying health condition. The horse is a supreme athlete with a powerful heart...

Equine pinworms, or Oxyuris equi, are common parasites that inhabit the horse's colon. Female pinworms lay their eggs on the perianal skin (around the anus), which can cause intense itching and irritation for the horse. Pinworm infections are most common...

The horse’s tendons are prone to strain injuries, especially when participating in disciplines, such as racing, jumping and eventing. Tendons are fibrous connective tissues that attach muscle to bone and allow the limbs to move. Tendons serve as a mechanical...

Eastern equine encephalitis (EEE), otherwise known as Triple E or sleeping sickness, is a rare and lethal virus in horses that causes inflammation of the brain. EEE is transmitted through mosquito bites and attacks the central nervous system (CNS). It...

Feeding horses with pituitary pars intermedia dysfunction (PPID), previously referred to as Equine Cushing’s disease, can be a challenge. Horses affected by PPID are typically older and may have other health issues including equine metabolic syndrome (EMS). This condition can...

Narcolepsy is a neurological and rapid eye movement (REM) sleep disorder. It involves the sudden onset of sleep during the daytime. The condition occurs chronically and throughout life in affected horses unless treatment is provided. Two types of narcolepsies are...

A hunter’s bump, or sacroiliac subluxation, is a hump on the horse’s lower back that develops above the croup. It is most apparent when viewing a horse in motion from behind.

Heat stress occurs when the horse’s internal cooling mechanisms stop working efficiently and the ability to maintain a normal body temperature is affected. This is common and in hot and humid conditions, or following vigorous exercise. Without intervention, heat stress...

Enteroliths are calcifications or mineral masses that can form in the horse's intestines, sometimes resulting in impaction colic. These intestinal stones form when the horse consumes an indigestible object, which is not passed by the digestive system. Mineral deposits then...

Hypothyroidism refers to inadequate production of thyroid hormones, primarily thyroxine and (T4) and triiodothyronine (T3). These hormones are produced by the thyroid gland and play a role in regulating your horse's metabolism. Hypothyroidism most commonly occurs in neonatal foals and...

Shivers, or shivering, in horses is a progressive neuromuscular condition characterized by an abnormal, jerky gait while backing up. Horses affected by Shivers exhibit muscle tremors in the pelvic limbs when forced to back up. Clinical signs typically appear in...

Pituitary Pars Intermedia Dysfunction (PPID), previously referred to as Cushing’s Disease, is an endocrine-related disease that affects approximately 20-25% of senior horses, ponies, and donkeys. Signs of PPID in horses include abnormal hair coats, muscle atrophy, loss of topline, poor performance, regional...

Bowed tendon in horses is defined as acute or chronic inflammation of a tendon. This condition is also known as tendinitis, tendonitis or tendinopathy. This injury usually occurs when the tendon is strained beyond its limit, resulting in torn collagen...

Impaction colic in horses is a painful condition caused by an obstruction in the gastrointestinal (GI) tract. It is a serious and sometimes fatal condition. The term colic describes abdominal pain or discomfort in horses. Cases of colic are generally...

Strange lumps, itching, bald spots, redness, skin flaking, and scruffy patches are common signs of skin problems in horses. While most equine skin irritations don’t present serious health risks, persistent skin problems can lead to infections and could indicate allergies,...

Angular limb deformities (ALDs) and flexural deformities (FDs) frequently affect foals’ legs. When severe, they are deemed clinically significant and require conservative management or veterinary intervention to achieve correction.

Tetanus, or lockjaw, is a non-contagious neurological disease that results from a bacterial infection. Horses are particularly vulnerable to tetanus, with individuals of all ages and breeds affected worldwide. Tetanus spores are particularly dangerous for horses as they survive for...

Botulism is a fatal neuroparalytic disease that affects horses, humans and other animals worldwide. Botulism interferes with nerve signalling, weakening and often paralyzing the horse. This disease is caused by the ingestion of botulinum toxin produced by Clostridium botulinum bacteria....

Alopecia or hair loss in horses can occur for several different reasons and may be temporary or permanent. Alopecia refers to the partial or complete absence of hair that occurs in any area of the body where hair is normally...

Horses are prone to hoof cracks for various reasons. Cracks can lead to the hoof chipping away in certain areas. Cracks can be a cosmetic problem that can be easily corrected, but sometimes, they indicate something more serious is happening within...

Photosensitization, or light-induced dermatitis (photodermatitis), is a noncontagious condition in horses where the skin becomes extremely sensitive to sunlight. This condition often mimics a sunburn, but it is much more serious and painful. Photosensitization is most commonly caused by ingesting...

It’s not uncommon for horses to experience eye problems. Several conditions and diseases can affect vision and eye health in horses, including uveitis, cataracts, and conjunctivitis. Horses experiencing eye issues may have symptoms such as swelling, tearing, drainage, discoloration, cloudiness,...

Myosin Heavy Chain Myopathy (MYHM) is a muscle disease that can affect Quarter Horses and related breeds with the associated mutation in the MYH1 gene. MYH1, also called myosin heavy chain 1, is a gene that encodes a type of...

Coughing is a common clinical sign in horses that can be entirely benign or the first clue of a medical condition. Your horse’s cough is a normal reflex that keeps his airway healthy and clean. But some conditions associated with...

Lasix (furosemide) is a medication routinely used to prevent lung bleeding in horses with exercise-induced pulmonary hemorrhage (EIPH). This bleeding disorder is prevalent in racehorses following bouts of high-intensity exercise. Veterinarians often recommend treating with Lasix on race days to...

Retained fetal membranes (RFM), also referred to as retained placenta, is a condition that affects a small percentage of broodmares. RFM can lead to serious medical complications in affected mares and requires prompt treatment. Potential complications of RFM include laminitis,...

Shipping fever is a lower respiratory tract infection seen in horses transported over long distances or experiencing unusual or stressful events. Known causes of shipping fever include prolonged periods of head elevation, strenuous exercise, anesthesia or complications from a viral...

Sand colic is a term for abdominal pain in horses caused by the ingestion of sand. Depending on the geographic region, five to thirty percent of all colic cases are caused by sand or sediment accumulation in the gut. Sand...

Of the many skin conditions horses can develop, sarcoids are the most common. The term "sarcoid" was first used in 1936 in South Africa as a way to distinguish this skin lesion from other tumors. Sarcoids are benign (nonmetastatic) skin...

Myofibrillar myopathy (MFM) is a newly identified muscle disorder that causes exercise intolerance in horses. MFM is a genetic condition that results from the abnormal build-up of desmin in muscle tissue. Desmin is a protein that is important for muscle...