Conditions

African horse sickness (AHS) is a viral infection transmitted by biting midges. Up to 90% of horses infected with the virus die after initial infection. [ref n="1"] Due to international trade and climate change, there is a risk of AHS...

Horse eyes are prominent, making them prone to injury. This is especially true of the cornea, which is the outermost layer of the eye. An injury to this layer is known as a corneal ulcer or keratitis. Corneal ulcers can...

Equine recurrent uveitis (ERU) is an autoimmune disease and the leading cause of blindness in horses. The disease results in the immune system repeatedly attacking the structures of the eye causing tissue damage, inflammation, and eventually blindness. The underlying cause...

Ear mites are tiny, wingless, external parasites that live in the ears of horses and cause psoroptic mange. They are round with eight legs and are sometimes visible to the naked eye. They do not burrow into the horse but...

Mange is a skin and coat condition in horses caused by microscopic parasites called mites. Although mange is not common in horses, specific conditions can lead to a mite infestation that can spread rapidly between horses in direct contact. Mange...

When a horse lies down for extended periods, especially with long-heeled horseshoes or on shallow bedding, prolonged pressure and "squishing" from the hoof on the elbow can occur, leading to a condition known as shoe boil. Shoe boils, otherwise known...

As with other parasites that feed on blood, mosquitoes can transmit diseases between hosts. In horses, Eastern, Western, and Venezuelan Equine Encephalitis (EEE, WEE, and VEE, respectively) and West Nile Virus are mosquito-borne illnesses. Equine encephalitis and West Nile viruses...

Lice are an external parasite found on the hair or fur of mammalian hosts, including horses. A lice infestation is also referred to as pediculosis. There are different species of these small, wingless insects, and horses are usually infested with...

Cataracts are cloudy areas within the horse's lens, the structure within the eye that directs light to the retina. [ref n="1"] The lens must be clear to allow light to pass through correctly, meaning that cataracts can cause blindness in...

Glaucoma refers to increased intraocular pressure, the fluid pressure within the eyeball that gives the eye its shape. [ref n="1"] Glaucoma in horses develops when there is an imbalance in fluid drainage at the front of the eye, leading to...

Equine herpesvirus-1 myeloencephalopathy (EHM) is a potentially fatal consequence of equine herpesvirus-1 (EHV-1) infection in horses. EHV-1 spreads through contact with an infected horse or surfaces contaminated with the virus. Affected horses develop incoordination, weakness, and paralysis 6-10 days after...

Degenerative joint disease (also called arthritis) refers to degeneration and loss of the articular cartilage, cartilage within a joint space that protects the bones on either side of a joint. As the articular cartilage degenerates, the bones contact each other,...

Equine degenerative myeloencephalopathy (EDM) is a degenerative neurologic disease affecting the brain and spinal cord in horses. [ref n="1"] The precise cause of EDM is unknown, but it may be related to a combination of vitamin E deficiency in the...

Neurectomy refers to the surgical cutting and removal of a nerve to prevent pain sensation. In horses, neurectomy is considered a salvage procedure, meaning it is a last resort only performed if no other treatments were effective. Veterinarians may recommend...

Blister beetles, also known as oil beetles, secrete a blistering agent called cantharidin as a natural defense against predators. Beetles in this family feed on flower blossoms, particularly in alfalfa plants, which makes them a common contaminant in alfalfa hay....

Alsike clover toxicosis is a potentially life-threatening condition in horses caused by ingesting large quantities of the Trifolium hybridum plant, commonly referred to as Alsike clover. To date, neither the precise mechanism of action nor the specific toxin from Alsike...

Poisonous snake bites (snake envenomation) in horses, while not common, are a medical emergency. Without prompt veterinary attention, snake envenomation can result in severe injury and, in some cases, death. In North America, venomous snakes belong to either the Elapid...

The guttural pouches are large, air-filled structures within the horse's skull, in the throatlatch region. These pouches can develop bacterial infections, fungal infections, or tympany, the excessive accumulation of air. Most diseases of the guttural pouches are not life-threatening. However,...

Progressive ethmoidal hematomas (PEHs) in horses are non-cancerous masses that develop from the ethmoidal labyrinth. This is a structure with a high concentration of blood vessels within the horse’s nasal [...]

Immune-mediated myositis (IMM) is a muscle disorder in horses where the immune system mistakenly attacks its own muscle fibers, resulting in severe muscle atrophy. IMM is one of the two disorders classified under Myosin Heavy Chain Myopathy (MYHM) in horses....

Oxalates are naturally occurring compounds that bind calcium in the equine diet, preventing absorption of this mineral from the horse’s gut. When horses consume plants with high levels of these [...]

The overo pattern is one of three coat patterns in American Paint Horses (APHs) recognized by the American Paint Horse Association (APHA), along with Tobiano and Tovero. Among Overo variations, the frame overo subtype stands out for its distinctive markings....

Platelet-Rich Plasma (PRP) is a regenerative therapy used to treat horses with tendon and ligament injuries. PRP is a blood preparation where plasma, the water and protein component of blood containing no cells, is mixed with highly concentrated platelets and...

Pulsed electromagnetic field (PEMF) therapy is a treatment modality for horses where a machine produces pulses of electromagnetic fields directed at a specific part of the body. Research suggests that PEMF can improve bone healing rates, regenerate and protect cartilage...

Habronematidosis or habronemosis, more commonly known as summer sores, is a parasitic skin infection that can occur in horses. As the name implies, summer sores usually occur during the summer months.

Chiropractic care for horses is a form of manual therapy commonly used in veterinary treatment protocols for lameness. Chiropractic treatment focuses on joint mobilization and manipulation to reduce pain, improve symmetry, and increase range of motion.

Exertional Rhabdomyolysis (ER), commonly known as tying-up or azoturia, is an exercise-induced condition in horses characterized by the excessive breakdown of muscle tissue. This results in muscle spasms, pain and impaired performance following bouts of exercise. [1] In severe cases,...

Leptospirosis is a bacterial infection that is commonly spread to horses through direct contact with contaminated food and water sources. While there are many different species of the Leptospira bacteria, symptoms in horses are most commonly caused by Leptospira interrogans.

Sesamoiditis in horses refers to pain and injury around the sesamoid bones, pairs of small triangular bones found at the back of the fetlock. Inflammation in this area can cause pain and changes to the bony structure of the sesamoid...

Sacroiliac pain is a common cause of poor performance and low-grade lameness in performance horses. The sacroiliac joint is the point on the horse’s body where the pelvis and the spine connect, playing an important role in their stride.