Skin and coat problems

World Horse Welfare says skin conditions are the most common of all the conditions that affect horses, and most are easier to deal with when they're spotted early. Grooming gives you the chance: run your hands over your horse's whole body and legs, and look for scabs, sore or hot patches, hair loss, rubbing and itching. See how to groom your horse.

At a glance

Mud fever

Mud fever, also called pastern dermatitis, greasy heel or cracked heels, is a skin infection of the lower legs. The BHS says it's most often caused by bacteria: wet weather softens the skin, and mud rubbing against it damages the surface and lets bacteria in. It isn't contagious.

Signs. The BHS lists crusty scabs on the heels or lower legs, broken skin, matted hair or patches of hair loss with raw skin underneath, a creamy, white, yellow or green discharge under the scabs, and heat, pain and swelling. Severe cases can make a horse lame. World Horse Welfare adds that in severe cases the skin can split at the back of the leg.

Horses more at risk, according to the BHS:

• horses standing in wet, muddy conditions or dirty bedding for long periods
• horses whose legs are washed often, especially if they aren't dried
• horses with wounds or broken skin, such as an overreach injury
• white legs, because the pink skin under white markings is often more sensitive
• thin-skinned breeds such as Thoroughbreds and Arabs
• horses with a weakened immune system, for example from Cushing's disease
• feathered horses, which often have leg mites: the itching breaks the skin

Treatment. Call your vet when you first suspect mud fever, so it can be properly diagnosed. Your vet may then be happy for you to treat it. The usual approach, from the BHS and World Horse Welfare:

1. Bring your horse out of the mud, somewhere clean and dry.
2. Wash the area with a very dilute antiseptic such as Hibiscrub, in warm water, never cold. World Horse Welfare suggests a 0.1% solution, left on for 10 minutes then rinsed off fully. Never put neat Hibiscrub on the skin.
3. Dry the leg thoroughly by patting it with a clean towel.
4. Remove loose scabs gently. Don't force scabs off unless your vet advises it: it's painful, and sedation may be needed.
5. Your vet may suggest a cream. Apply creams only to clean, dry skin.

Thick feathers make it hard to clean and dry the skin, so you may need to clip the leg. Call your vet back if it isn't improving or the leg swells: the BHS warns that untreated mud fever can lead to cellulitis or lymphangitis, infections that cause the leg to swell.

Prevention. From the BHS, World Horse Welfare and Bransby Horses:

• Check legs every day in wet weather.
• Give your horse somewhere dry to stand for part of the day. Put hardcore or mud mats in gateways and around troughs, rotate fields and fence off the worst mud.
• Don't wash legs every day. Let mud dry and brush it off, or dry the legs thoroughly if you do wash them.
• Keep bedding clean.
• Use barrier creams before turnout only on clean, dry skin; otherwise they trap bacteria against it.
• Turnout boots can help if they fit well, without rubbing.
• Treat mites, wounds and other underlying problems.

Rain scald

Rain scald can be caused by the same bacteria as mud fever, but the scabs form along the neck, back and quarters. The BHS says it's often seen in autumn and winter, and also in horses that are over-rugged and sweaty. The scabs come off with tufts of hair, like little paintbrushes. It isn't contagious, but the bacteria in the scabs can reinfect the horse, so disinfect grooming kit and tack.

Check it's not ringworm. The BHS says it's important to confirm the scabs aren't a different condition, such as ringworm, which is a highly contagious fungal infection. Your vet may take a sample or a skin scraping.

Treatment. Bring the horse out of the wet. The BHS says to clean the scabs with a suitable antibacterial solution such as dilute Hibiscrub, then dry them gently, usually every day until it heals. Your vet may prescribe a cream, or antibiotics in severe cases. If the saddle area is affected, the horse may not be able to be ridden until it's healed.

Prevention. Shelter in the field, time indoors to dry off, and a rug for a thin-coated, clipped or underweight horse. Avoid over-rugging, which makes the horse sweat. Groom off clumps of mud, but don't over-groom a horse that lives out.

Sweet itch

Sweet itch is an allergic reaction to the saliva of biting midges, and sometimes other biting insects. World Horse Welfare says it's the most common allergic skin disease in the UK, affecting around 5% of horses. It can affect any horse, but the BHS says some are at greater risk, including native ponies such as the Exmoor, Icelandic horses and Belgian warmbloods.

Signs. The BHS lists intense itching, shown by rubbing on fences, trees and doors, rolling, tail swishing and head shaking. It usually affects the base of the mane, the withers, tail, face and ears. Over time the hair breaks and thins, the skin thickens and folds, and rubbed areas can become sore, weeping and infected. Affected horses can become irritable, restless or lethargic. Signs are worst between March and November, when midges are active.

Other allergies can look very similar, so ask your vet to confirm it.

Prevention. There's no cure, so the aim is to stop midges biting. The BHS and World Horse Welfare suggest:

• A fly rug and mask covering as much of the body as possible. World Horse Welfare suggests having a spare, so you can wash and rotate them. The BHS notes that zebra-print rugs have been shown to reduce fly bites.
• Shelter from dusk until after dawn, when midges are most active.
• Location. Keep away from standing water, waterlogged ground, woodland and muck heaps. Windy fields have fewer midges.
• Stable mesh and fans. Fine mesh over doors and windows keeps midges out; the BHS says midges are poor fliers, so a safely placed fan helps.
• Fly repellent. Repellents containing pyrethroids or permethrin are often the most effective, says World Horse Welfare. Test DEET on a small area first. Don't use repellents on broken skin.

Relief. Soothing shampoos and sprays can help. World Horse Welfare says research has shown supplements containing omega-6 and omega-3 fatty acids can reduce itching. Your vet can advise on medicines. World Horse Welfare warns that long-term steroids increase the risk of laminitis, so they should only be used as your vet prescribes. Clipping the hair around sores at the top of the tail or the mane makes them easier to clean, says Bransby Horses.

Feather mites

Chorioptic mange, or "feather mites", is caused by tiny mites that live on the skin and feed on skin debris. The University of Liverpool says heavily feathered horses are most often affected, though any horse can be. The mites are about 0.3mm long, too small to see easily.

Signs. Stamping, rubbing one leg against another or against stable fittings, biting at the legs, and scabs or small bleeding wounds on the lower legs. The University of Liverpool says signs are often worse in winter, when horses are stabled more. Scurfy flakes often follow: if the horse isn't itchy, Liverpool says the scurf isn't a great worry. Crusty patches can form behind the knee (mallenders) and in front of the hock (sallenders).

Treatment. Ask your vet as soon as you see signs: World Horse Welfare says early treatment is important. Treatment often involves:

• clipping the feathers, so treatments reach the skin. Liverpool says clipping alone is unlikely to cure the problem.
• washing the legs with an anti-parasitic shampoo, and repeating it 10–14 days later to catch newly hatched mites
• treatments from your vet. World Horse Welfare notes that no veterinary products are licensed in the UK to treat mites in horses, so vets use products licensed for other uses.
• treating every horse that's in contact with the affected one, and disinfecting stables

Mites can live in the environment for around 70 days, says Liverpool, so reinfection is common. Some traditional remedies can help, but others, such as engine oil, may be useless and harmful.

For more on feathered horses, see heavy horse care.

Ringworm

Ringworm is a fungal skin infection, not a worm. The BHS describes it as highly contagious, and says it can be mistaken for rain scald. The BHS's disease-prevention advice is that infections can spread indirectly on shared tack and grooming kit, so every horse should have its own grooming equipment, cleaned regularly. If you suspect ringworm, keep the horse's kit and tack separate and ask your vet to confirm the diagnosis.

Sunburn

Pink skin under white markings burns easily, particularly on the nose. To protect it:

• Provide shade or shelter.
• Apply a high-factor sun cream to pink areas, says the BHS. World Horse Welfare suggests a horse sun cream, or a children's sunblock tested on a small patch first.
• Use a fly mask with UV protection.

If your horse does get sunburnt, World Horse Welfare says to get it out of the sun and cool the area with water. If the skin is crusty or weeping, call your vet straight away.

Rug rubs and sores

A rug that doesn't fit, or that's left on too long, can rub and cause injury. The BHS says to take rugs off every day to check, and refit or change any rug that's rubbing. Over-rugging also makes horses sweat, which leaves the skin more prone to infection. See clipping and rugging.

A coat that won't shed

A long, thick coat that is slow to shed in spring can be a sign of Cushing's disease (PPID), says the RVC, along with laminitis, weight loss, sweating, and drinking and urinating more. Bransby Horses says a clip helps affected horses stay comfortable. The RVC also says horses with PPID are more prone to skin infections. Speak to your vet if your horse's coat changes like this.