Theiler's disease, also known as equine serum hepatitis, is a viral infection likely caused by equine parvovirus-hepatitis. Horses most commonly develop Theiler's disease after administration of an equine-origin biologic product, such as serum or blood. Theiler's disease causes rapid onset...
Conditions
Explore Mad Barn’s comprehensive list of common equine health conditions, detailing each condition’s causes, symptoms, treatment options, prevention methods, and prognosis.
A
- Abnormal Gestation
- Abortion (Stillbirth)
- Acquired Heart Murmurs
- African Horse Sickness
- Anaplasmosis in Horses (Equine Granulocytic Ehrlichiosis)
- Anemia
- Anhidrosis (Absent Sweating)
- Anthrax Poisoning
- Arrhythmias (Irregular Heart Beats)
- Arthritis
- Ascarids Parasites
- Atrial Fibrillation
- Aural (Ear) Plaques
- Autoimmune disease - Primary Immunodeficiency Disorders
B
- Back Pain
- Bartonella Infection
- Big Head Disease (Nutritional Secondary Hyperparathyroidism)
- Black Walnut Tree Poisoning
- Bleeding Disorders
- Blister Beetle Poisoning (Cantharidin Toxicity)
- Bog Spavin (Tarsocrural Joint Effusion)
- Bone Bruises
- Bone Spavin
- Botflies Parasites
- Botulism
- Bowed Tendons
- Box Elder & Sycamore Poisoning
- Brain Anatomy & Disease
- Bucked Shins (Dorsal Metacarpal Disease)
- Buttercup Poisoning
C
- Canker
- Capped Hock (Calcaneal Bursitis)
- Cataracts
- Caudal Heel Pain
- Cellulitis
- Cerebellar Abiotrophy
- Choke
- Chronic Progressive Lymphedema
- Coffin Bone Lameness
- Colic in Foals
- Colic Treatment, Management & Prevention Guide
- Colitis
- Congenital Heart Murmurs
- Congenital Hypothyroidism & Dysmaturity Syndrome
- Conjunctivitis (Pink Eye)
- Contagious Colitis
- Contagious Equine Metritis
- Corneal Ulcers
- Cranial Nerve Conditions
D
- Degenerative Joint Disease (DJD)
- Degenerative Suspensory Ligament Desmitis (DSLD)
- Dehydration
- Dental Disease
- Developmental Orthopedic Diseases
- Dew Poisoning (Alsike Clover Poisoning)
- Dislocated Eye Lens
- Displacement Colics
- Dorsal Displacement of the Soft Palate in Horses (DDSP)
- Dummy Foal Syndrome (Neonatal Maladjustment)
- Dysmastication (Abnormal Chewing)
- Dystocia (Difficulty Foaling)
E
- Ear Mites & Psoroptic Mange
- Eastern Equine Encephalitis (EEE)
- Endometritis
- Enlarged Ovaries
- Enteritis & Inflammatory Bowel Disease
- Enteroliths
- Epilepsy
- Equine Chronic Obstructive Pulmonary Disease (COPD)
- Equine Coronavirus (ECoV)
- Equine Degenerative Myeloencephalopathy (EDM)
- Equine Gastric Ulcer Syndrome (EGUS)
- Equine Grass Sickness
- Equine Herpesvirus
- Equine Herpesvirus-1 Myeloencephalopathy (EHM)
- Equine Infectious Anemia (EIA)
- Equine Metabolic Syndrome (EMS)
- Equine Motor Neuron Disease
- Equine Odontoclastic Tooth Resorption & Hypercementosis (EOTRH)
- Equine Proliferative Enteropathy (Lawsonia)
- Equine Protozoal Myeloencephalitis (EPM)
- Equine Viral Arteritis (EVA)
- Equine Wobbler Syndrome (Cervical Vertebral Stenotic Myelopathy)
- Exercise-Induced Pulmonary Hemorrhage (EIPH)
- Eye Conditions
F
G
H
- Hay Belly
- Hay Belly & Other Causes of Bloating
- Heart Disease
- Heat Stress
- Heaves
- Hendra Virus (Equine Morbillivirus)
- Hepatitis
- Hereditary Equine Regional Dermal Asthenia (HERDA)
- Hindgut Acidosis
- Hindgut Ulcers
- Hives (Urticaria)
- Hoof & Sole Bruises
- Hoof Abscess
- Hoof Anatomy & Conditions
- Hoof Cracks
- Hoof Degloving
- Hunter’s Bump
- Hyperkalemic Periodic Paralysis (HYPP)
- Hyperlipidemia & Hyperlipemia
- Hypothyroidism
I
- Immune Mediated Myositis (IMM)
- Impaction Colic
- Inappropriate Lactation
- Infectious Diarrhea in Foals
- Inflammatory Airway Disease
- Influenza Virus (Flu)
- Inguinal (Scrotal) Hernias
- Injuries: Endurance
- Injuries: English Performance
- Injuries: Racehorses
- Injuries: Western Performance
- Insect Stings & Spider Bites
- Internal Entrapments (Reasons for Colic Surgery)
- Internal Parasites
- Intussusception
- Ionophore Toxicosis
- Iron Overload
J
K
L
M
- Mange
- Mare Reproductive Loss Syndrome
- Mastitis
- Melanomas
- Meningitis
- Mesenteric & Omental Rents
- Migrating Grass Awns (Foxtails)
- Moldy Hay (Mycotoxin) Poisoning
- Monensin Poisoning
- Moon Blindness (Equine Recurrent Uveitis)
- Mosquito-Borne Equine Diseases
- Most Common Equine Allergies
- Mud Fever (Equine Pastern Dermatitis)
- Myofibrillar Myopathy (MFM)
- Myosin Heavy Chain Myopathy (MYHM)
N
O
P
- Parrot Mouth (Rostral Malocclusion)
- Pasture-Associated Laminitis
- Pedal Osteitis
- Physitis
- Pigeon Fever
- Pinworms Parasites (Oxyuris Equi)
- Piroplasmosis (Babesiosis)
- Pituitary Pars Intermedia Dysfunction (PPID, formerly Equine Cushing's)
- Placentitis
- Pneumonia
- Podotrochlear Syndrome
- Polysaccharide Storage Myopathy Type 1 (PSSM1)
- Potomac Horse Fever
- Progressive Ethmoidal Hematomas
- Protein Bumps (Eosinophilic Granulomas)
- Proud Flesh (Granulation Tissue)
- Proximal or Anterior Enteritis
- Purpura Hemorrhagica
Q
R
- Rabies
- Ragwort Poisoning (Pyrrolizidine Alkaloid Toxicity)
- Rain Scald
- Rattles in Foals
- Reproductive Emergencies in Mares
- Respiratory Diseases
- Retained Fetal Membranes (Placenta)
- Rhino in Horses
- Right Dorsal Colitis
- Ringbone
- Ringworm (Girth Itch)
- Roach Back (Kyphosis)
- Roaring (Laryngeal Hemiplegia)
- Rotavirus
- Ryegrass Staggers
S
- Sacroiliac Dysfunction
- Salmonella Infection
- Sand Colic
- Sarcoids
- Scours (Foal Heat Diarrhea)
- Scratches (Pastern Dermatitis)
- Seasonal Respiratory Allergies
- Selenium Poisoning (Alkali Disease)
- Sepsis & Toxic Shock
- Septic Laminitis
- Sesamoid Injuries
- Sesamoiditis
- Shelly Feet
- Shipping Fever
- Shivers
- Shoe Boils (Olecranon Bursitis or Capped Elbow)
- Sidebone
- Sidewinder Syndrome (Crab Walking)
- Sinusitis
- Skin Allergies
- Skin Diseases Guide
- Skin Irritations
- Slobbers (Slaframine Poisoning)
- Small Intestine Volvulus
- Smoke Inhalation Injury
- Sorghum & Sudan Grass (Cyanide) Poisoning
- Splints in Horses
- Squamous Cell Carcinoma (SCC)
- Staphylococcus & MRSA
- Stocking Up (Stagnation Edema)
- Stovepipe Leg (Lymphangitis)
- Stovepipe Leg (Lymphangitis)
- Strangles
- Strangulating Lipomas
- Stringhalt
- Strongyles Parasites
- Summer Sores (Habronema)
- Supporting Limb Laminitis
- Swayback (Equine Lordosis)
- Sweet Itch (Insect Bite Hypersensitivity)
- Swollen Sheath
- Synovial Joint Infections
T
- Tapeworms Parasites
- Tendon Injuries
- Tetanus
- Theiler's Disease (Equine Serum Hepatitis)
- Threadworms <em>(Strongyloides Westeri)</em>
- Thrush
- Thumps (Synchronous Diaphragmatic Flutter)
- Tick-Borne Disease [Guide]
- Top 30 Most Common Equine Diseases
- Top 6 Gastrointestinal Conditions in Horses
- Trigeminal Mediated Headshaking Syndrome
- Twisted Gut (Intestinal Torsion)
- Tying-up (Exertional Rhabdomyolysis)
- Tying-up (Exertional Rhabdomyolysis)
- Tyzzer's Disease
U
V
W
Z
Monensin is a type of antibiotic commonly found in livestock and poultry feed that is highly toxic to horses. Monensin belongs to a medication class called ionophore antibiotics. These antibiotics are frequently used in feed as parasite control and to...
Salmonellosis refers to infection with Salmonella, a bacterium that primarily causes intestinal infections and diarrhea. Salmonella can affect numerous species, including horses and humans. Horses typically acquire the bacteria through the ingestion of contaminated feed or water. Common symptoms of...
Bucked shins is a condition that affects the cannon bones of young race horses in the first 6 to 8 months of their speed training. Since the horse's bones are still developing, the strain of the training results in a...
Bog spavin is a common term for effusion in the horse's tarsocrural joint. This painful condition describes inflammation and fluid accumulation in the joint capsule between the tibia and the tarsal bones in the hock. Bog spavin is characterized by...
The horse's gastrointestinal system is evolved for processing forage and fiber. Domestic feeding and management strategies often challenge the horse's natural digestive process. Significant disruptions can lead to bloating - a condition where gas accumulates in the gut, causing abdominal...
During fetal development, the testicles form near the kidneys and gradually descend into the scrotum through a passage called the inguinal canal. In some cases, this descent is incomplete, resulting in one or both testicles being retained within the abdomen...
Staphylococcus bacteria are a common member of the equine microflora, found on the skin, in the nasal passages, and in the intestines. These bacteria typically do not cause infection or disease. However, under certain circumstances, the bacteria may take advantage...
Anthrax is a rapidly fatal disease caused by the bacterium Bacillus anthracis. This bacterium can infect horses, other livestock species, and humans. Anthrax cases occur globally every year, including sporadic outbreaks in North America. B. anthracis primarily exists as spores...
In recent years, extensive and persistent wildfires have been a growing concern for horse operations everywhere. Evacuation and preventive protocols are often challenging and put a great deal of strain on livestock and their human caretakers. Equally as concerning is...
Liver health is paramount to the overall well-being and performance of horses. It is one of the largest and most vital organs in the equine body. This organ plays a crucial role in numerous physiological processes including metabolism, digestion, detoxification,...
Hives, also known as urticaria, are a common skin reaction in horses characterized by the sudden appearance of raised, swollen wheals on the skin. These wheals can vary in size, and may be accompanied by itching or discomfort. Hives in...
Selenium (Se) is a micronutrient that horses require in trace amounts to support cellular function. The selenium content in soil contributes to its final concentration in plants. Worldwide, selenium levels in soil vary widely. Selenium imbalances are common in horses....
Parasites are organisms that live in or on the horse, and rely on the horse for sustenance while often causing harm or disease. These include worms like roundworms, tapeworms, and bots, as well as external parasites such as ticks and...
Keratosis is an equine skin condition where patches or bands of skin become thickened, rough, dark, and oily. The patches are not painful nor itchy, are not contagious, and do not impact the overall health of the horse. There are...
Ringworm, or dermatophytosis, is a common fungal skin infection. Despite its name, ringworm isn't caused by a worm but rather by various fungi, or dermatophytes, that infect the skin. This fungal infection presents circular hair loss patches with crusty, scaly...
Pyrrolizidine alkaloids (PAs) are a naturally occurring type of compound found in many species of plants. When ingested, PAs are toxic to horses. Some of the most common plants that contain high concentrations of PAs include Ragwort (Senecio spp.), Rattlepod,...
As horse owners the world over know, equines are prone to many forms of gastrointestinal disease and dysfunction. Strangulating lipomas are among the varied and complex risks of GI disruption in horses. A lipoma is a tumor made of fat...
Hereditary Equine Regional Dermal Asthenia (HERDA), or Hyperelastosis Cutis (HC), is a genetic degenerative skin disease that primarily affects Quarter Horses. It's characterized by a collagen deficiency, a crucial protein responsible for maintaining the strength and elasticity of the skin....
Proximal Enteritis (also known as Anterior Enteritis) describes inflammation of the first two parts of the horse's small intestine. Proximal Enteritis (PE) is a serious concern for horse owners, as it can block passage of food and water through the...
Horses are susceptible to a variety of external pests and parasites. Most equine pests are either insects or arachnids, some of which can cause irritation, discomfort, and even life-threatening reactions. Several species of external parasite can cause severe health problems...
Vesicular stomatitis is a viral disease that more commonly affects horses living in warmer climates. The disease typically results in blister-like lesions (referred to as vesicles) forming in and around the mouths of horses and other farm animals. This condition...
Hendra virus (HeV), also known as equine morbillivirus, is a frequently fatal viral infection that can affect both horses and people. All reported cases of human Hendra virus infection occurred after exposure to an affected horse, emphasizing the significance of...
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...