My horse has a skin problem

Skin & Coat

Itching, rubbing, bald patches, flaky or inflamed skin — skin issues are rarely just skin.

Immune System & Allergies

Allergic reactions, recurring infections, constant sensitivity — the immune system is closely connected.

Digestion & Gut

Free faecal water, diarrhoea, recurring colic, a sensitive digestion — the gut is a central system.

Metabolism & Endocrine

Excess weight, a tendency to laminitis, Cushing's, a burdened metabolism — endocrine topics affect the whole organism.

Anaphylaxis is an acute, generalised allergic overreaction of the immune system (usually IgE-mediated) with massive histamine release. Within minutes it can threaten circulation and breathing and is a life-threatening emergency. Typical triggers are injections (medicines, vaccines, sera), insect stings or, more rarely, feed components.

In choke, a feed bolus or foreign body blocks the esophagus so that feed and saliva cannot be swallowed. Unlike in humans, breathing is usually unaffected — nevertheless choke is an acute veterinary EMERGENCY.

The coat change is a metabolically intensive phase; a sluggish, delayed or incomplete change can indicate increased nutrient demand, metabolic strain or an underlying disease. In older horses, a delayed coat change is a classic warning sign of PPID (Cushing).

Colic is an emergency with many causes — a substantial part of the risk factors lies in feeding and husbandry management and is controllable.

Chronically progressive disorder of the lymph drainage in the lower legs of heavily feathered breeds (among others Shire, Clydesdale, Belgian Draught, Tinker). There is increasing swelling, skin folds and nodule formation under the dense feathering; a hereditary predisposition for a disturbed elastin/connective tissue regulation is assumed. CPL is not curable but can be slowed by consistent management.

KPU is a term widely discussed in practice for a presumed metabolic/detoxification disorder, but it is NOT recognised in established veterinary medicine as a distinct, scientifically proven disease. Robust studies are lacking; the attributed symptoms are non-specific and can have many other causes.

Diarrhea is a symptom, not a disease in itself, and ranges from harmless and transient to life-threatening. Acute, watery diarrhea with fever or apathy can indicate a serious infection and lead to dangerous fluid loss.

Dysbiosis describes a gut microbiome that has lost balance, e.g. after starch-rich feeding, antibiotics or abrupt ration changes. A stable microbiome is considered important for fibre digestion, nutrient supply and immune status; research on this is still young.

Sarcoids are the most common skin tumours in horses — locally aggressive, fibroblastic skin growths associated with bovine papillomavirus (BPV-1/-2). They do not metastasise but tend to recur and can become more aggressive after irritation.

In a true feed allergy, the immune system reacts to a feed component, usually with skin or digestive symptoms. In horses, however, it is rare and often overdiagnosed — many supposed allergies are non-immunological intolerances or have other causes. Proof is demanding and best achieved through a controlled elimination diet.

In free fecal water syndrome, free, often brown liquid is passed in addition to formed manure, soiling the tail and hindquarters. Causes are considered multifactorial and not yet scientifically settled; general condition is usually unaffected.

Damage to the stomach lining from acid load, feeding gaps, stress and starch-rich rations. Very common in sport horses.

Hereditary connective tissue disorder of the skin (collagen defect through a mutation in the PPIB gene), in which the skin layers are insufficiently anchored. HERDA is inherited autosomal-recessive and occurs above all in certain cutting/performance lines of the Quarter Horse; only homozygous animals are affected, carriers are clinically unremarkable.

Acute, often allergic or pseudo-allergic skin reaction with suddenly appearing raised wheals. Can be harmless and transient but may recur — and is a warning sign with accompanying swelling or breathing difficulty.

In hyperlipemia, mobilised fatty acids flood the blood and are deposited as fat in the liver — triggered by a negative energy balance (feed refusal, stress, pregnancy/lactation). Ponies, donkeys and miniature horses are especially affected; the course can be life-threatening.

Insulin dysregulation is a disturbed sugar/insulin metabolism with an excessive or sustained insulin response, often the core of EMS. It is considered a central risk factor for endocrinopathic laminitis and is objectified via blood diagnostics.

Insulin dysregulation with a tendency to obesity and a high risk of endocrinopathic laminitis. Common in easy-keeper breeds/ponies.

Lymphangitis is a painful inflammation of the lymph vessels and surrounding tissue, usually in one hind leg, with marked swelling. Triggers are often bacterial infections via small skin lesions (e.g. with mud fever), more rarely non-infectious/immune-mediated processes. It runs acutely, is very painful and tends to recur.

Skin disease caused by parasitic mites (often Chorioptes on the pastern/lower leg, less often Sarcoptes/Psoroptes) with intense itching, scaling and crusts. Mange is contagious and often transmitted via contact or shared equipment.

Not only deficiency but also an imbalance of major and trace elements (e.g. the ratio of copper to zinc or calcium to phosphorus) can affect skin, horn, muscle and metabolism. Since hay varies strongly by region, imbalances are best assessed via ration and blood analysis.

Umbrella term for an inflammatory skin reaction in the pastern fold with weeping, crusty or fissured areas. Usually multifactorial (wet, dirt, friction) and can be complicated by bacteria or mites.

Overweight is widespread in leisure horses and not a cosmetic issue: excess body fat is metabolically active and raises the risk of insulin dysregulation and laminitis. The Body Condition Score (BCS) helps to assess condition objectively.

Pemphigus foliaceus is the most common autoimmune skin disease of the horse. The immune system forms antibodies against connecting proteins of its own epidermal cells, so that skin layers detach and pustules, crusts and scales form. The changes often start on the head, legs or lower abdomen and can spread.

In photosensitisation, the skin overreacts to sunlight because light-active substances (photosensitisers) in the skin release UV energy and damage tissue. Mainly unpigmented, white skin areas are affected. A primary form (photosensitisers directly from plants) is distinguished from a secondary, liver-associated form, in which a damaged liver no longer sufficiently excretes a chlorophyll breakdown product (phylloerythrin).

Dysfunction of the pituitary gland (pars intermedia) with hormone dysregulation, mainly in older horses. Raises the laminitis risk, among others.

Purpura haemorrhagica is an immune-mediated, necrotising inflammation of small blood vessels (type III hypersensitivity). It classically appears about two to four weeks after a strangles infection (Streptococcus equi) or, more rarely, after vaccination/other infections, when the immune system damages the vessel walls with cross-reacting complexes. Typical are extensive oedema and pinpoint mucosal bleeding.

Bacterial skin infection caused by Dermatophilus congolensis that flares up with persistent wetness. Typical are crusty, paintbrush-like matted hair tufts along the topline; bald patches appear after the crusts come off.

Contagious fungal infection of the upper skin layers (usually Trichophyton/Microsporum) with circular, scaly, hairless patches. Highly contagious between horses and transmissible to humans (zoonosis).

In sand colic, ingested sand accumulates in the large intestine and can cause irritation, diarrhea, impaction or painful colic. Acute colic is always a veterinary EMERGENCY — sand accumulation can become life-threatening.

Hereditary, severe defect of the immune defence in the Arabian foal: through a mutation in the DNA-PKcs gene (PRKDC) functional B and T lymphocytes are not formed. SCID is inherited autosomal-recessive; affected foals are practically defenceless against infections after the maternal antibodies from the colostrum are used up. The disease is not curable, affected foals usually die in the first months of life.

Allergic skin reaction (hypersensitivity to the saliva of biting midges) with intense itching, mainly at the mane crest and tail base.

Hereditary connective tissue disorder of the Warmblood through a mutation in the PLOD1 gene (disturbed collagen cross-linking), inherited autosomal-recessive. Affected homozygous foetuses are mostly aborted or come into the world with extremely vulnerable, tearing skin and overextensible joints; the form is regarded as predominantly lethal. Carriers are clinically unremarkable and relatively frequent in Warmbloods.

Horses practically always carry some worm burden; only a high or damaging infestation (e.g. small strongyles, ascarids, tapeworms) becomes problematic. High burden can cause digestive disorders, weight loss and an increased colic risk — growing dewormer resistance makes a controlled approach important.