5 common horse winter skin conditions

Muddy gateways, soggy fields and wet rugs — if you’re a horse owner, there’s no getting away from winter conditions. Here’s how to spot common winter skin conditions and what to do about them.

What causes winter skin problems in horses?

The answer is simple: the weather — particularly in the UK, where our wet winters increase moisture levels in the environment.

‘This creates conditions that break down the protective oily layer on a horse’s skin, allowing bacteria to thrive,’ Gil explains. ‘The thicker rugs we use in winter can also lead to sweating, again increasing dampness and moisture. And horses that share rugs are particularly prone to skin infections, as rugs can easily transfer bacteria and fungi.’

5 common horse skin conditions and how to avoid them

1. Rain scald and mud fever
2. Equine lice and mange
3. Ringworm
4. Folliculitis
5. Thrush

1. Rain scald and mud fever

We’ve grouped these together because they are caused by the same bacteria. ‘Rain scald affects a horse’s back, the sides of his chest and his hindquarters,’ explains Gil, ‘whereas mud fever affects the legs.’ Because these conditions weaken the integrity of the skin, they can lead to secondary infections, such as cellulitis, if left untreated.

What to look out for

• Rain scald signs: A scabby coat and sore-looking pink skin in-between. Individual scabs may have tufts of hair on them. Scabs can vary in size and aren’t usually itchy.
• Mud fever signs: Painful scabs on your horse’s legs. These can also cause lameness, particularly if they form around the heels and coronet band. In severe cases, mud fever can lead to a deeper skin infection and you may notice swelling in your horse’s leg.

How to prevent and treat rain scald in horses

• Don’t pick at scabs! ‘They may be unsightly, but removing them can be very painful for your horse and cause the area to bleed,’ explains Gil. ‘It might also make your horse reluctant to let you near those areas again!’
• Keep rugs clean and dry. Rain scald will thrive in the warm, moist conditions under your horse’s rugs. So it’s important to make sure you choose the right rug for the time of year and adjust them accordingly. ‘Try not to over-rug as this causes sweating,’ Gil says. ‘Change rugs regularly, avoid sharing them (as well as brushes and tack) between horses to prevent cross-infection, and make sure your waterproof rugs keep the rain out.’
• Consider clipping. Sweat creates the ideal conditions for bacteria to live. Clipping your horse’s winter coat will help to reduce sweating, particularly if you have a native horse or pony with a fluffy winter coat.

How to prevent and treat mud fever in horses

• Improve drainage around gates. Your horse is more likely to get mud fever if they’re turned out on wet ground. Particularly where there’s standing water or puddles, like in muddy gateways where horses wait to be brought in. So improving drainage and laying gravel around these areas can help.
• Don’t overgraze. Rotate your horse’s turnout area if you can. This will help stop the ground being poached, keep mud to a minimum and paddocks will be in better condition for spring.
• Avoid over-washing legs. Do you hose your horse’s legs every time they come in? While this will keep them clean and remove mud, you are also contributing to the wet-dry cycle which can weaken the skin and increase the risk of infection. For mild cases, try wiping off excess mud, leaving legs to dry overnight, then brushing off dry mud in the morning.
• Use turnout boots. Mud fever boots or turnout boots wrap around your horse’s leg and usually cover from below the coronet band to the knee. Boots must be washed and dried daily, then put on clean legs, so it’s best to have two pairs!

If in doubt, ask your vet

Gil recommends treating affected skin daily with a gentle disinfectant that’s been diluted in warm water, then towel dry. But in more severe cases of rain scald and mud fever, you may need a steroid cream and/or antibiotic from your vet. Most vets will recommend that you keep your horse stabled (and therefore dry) while you treat the condition.

2. Equine lice and mange

Parasites like lice and mange can affect any horse, but they most commonly affect breeds with longer hair. So it’s no surprise that fluffy winter coats can increase the risk, too. Horses with Cushing’s disease (a condition where too much of the hormone cortisol is produced, leading to a weakened immune system) are also more susceptible.

What to look out for

• Itching! Lice are small and very hard to spot, but you’ll see your horse itching.
• Stamping feet and rubbing legs. Mange is caused by a mite that feeds on the debris on the surface of the skin, and is particularly attracted to the feathers of the lower limbs (hence the name ‘feather mite’). ‘The mites crawl along the skin,’ explains Gil, ‘which is very irritating for a horse, causing him to stamp and rub his lower limbs.’
• Lameness. Horses who are irritated by lice or mites can inflict injuries on themselves which can be severe, causing pain and potentially lameness.

How to prevent and treat horse lice

• Don’t over-rug! ‘Lice and mites love warmth and moisture, so, again, try to make sure you don’t over-rug,’ Gil recommends.
• Treat with a horse lice powder. As the powder only kills off adult lice and not eggs, keep in mind that you’ll need to treat your horse again in 10 to 14 days to take care of any that have hatched in the interim.
• Isolate horses with lice. Parasites can pass easily from one horse to another so if you suspect lice, it’s best to separate your horse from the herd while you treat them. Lice are also very small and hard to spot, especially on unclipped winter coats.

How to prevent and treat equine mange

• Seek veterinary advice straight away. A horse with mange needs immediate veterinary attention. ‘Your vet is likely to treat your horse with a wormer that is licensed for cattle, which is injected under the skin. This will be followed by a second treatment after 10 days, again to catch any that will have hatched in the meantime,’ Gil explains.
• Deep-clean your stable. Bedding like straw and shavings can harbour mites. So it should be removed from the infected horse’s stable and burnt to prevent re-infection.

3. Ringworm

Ringworm is a highly-infectious skin infection caused by a dermatophyte (‘skin-loving’) fungus. Ringworm scabs are easy to confuse with rain scald scabs, so speak to your vet as soon as you notice symptoms.

What to look out for

• Small raised spots on the skin. These spots can spread and a thick, dry and crumbly scab may form. They usually start as small red spots and then look more like a ‘ring’ as they get bigger, hence the name.
• Hair loss. Your horse will likely lose hair in scabby areas.

How to prevent and treat ringworm on horses

• Isolate your horse immediately. If you suspect your horse has ringworm, isolate them immediately to prevent the infection from spreading. Luckily, treatment is straightforward.
• Treat them with a fungicidal wash. ‘A fungicidal wash will effectively treat ringworm, and your horse’s hair will grow back within six to eight weeks,’ explains Gil. A course of 3 to 4 washes, with a few days between each, is recommended.
• Wash stable walls, rugs and brushes too. The ringworm fungus can live in the environment (for example, in rugs and wood fixtures around the stables) for up to 11 years and is also highly contagious, and can infect whole groups of horses in an outbreak. Gil recommends washing any areas of the stable that your horse was in contact with and all his rugs with the fungicidal before reusing them.

4. Folliculitis

‘This is a bacterial infection of a horse’s hair follicles,’ Gil says. ‘It’s most common in a horse’s saddle area, and thrives in warm wet conditions, so keep a lookout for it under rugs and as we head into spring.’

What to look out for

• Small red bumps or pustules. These develop around hair follicles and can break open and crust over, leaving your horse’s skin painful and tender.

How to prevent and treat equine folliculitis in horses

• Avoid over-rugging. Like other bacterial infections, folliculitis thrives in warm, wet conditions. So always rug appropriately for the temperature and change rugs regularly to keep your horse dry and sweat-free.
• Call your vet. ‘If your horse has contracted the condition, your vet will prescribe a longer-than-usual course of antibiotics, along with daily bathing of the area with warm water and disinfectant. With treatment, folliculitis should clear up within 10 to 14 days.’

5. Equine thrush

‘Compressed soil or bedding with poor drainage provides conditions where bacteria can thrive, which can then infect a horse’s foot and lead to thrush – specifically the troughs of the frog and the crevice between the heel bulbs,’ says Gil.

What to look out for

• Smelly, black discharge. This is the most common sign of thrush in horses. While a horse with the condition isn’t likely to be in pain at first, it can penetrate further into the foot and begin to cause him distress.

How to prevent and treat thrush in horses

• Pick out hooves twice a day. This will help to keep hooves free of mud and moisture, and you’ll be more likely to notice small changes before they become an issue.
• Maintain regular hoof care. Regular trimming and shoeing will also help to prevent thrush. If your horse requires treatment for equine thrush, your vet or an experienced farrier will need to trim away any under-run horn and open up the affected tissues to the air.
• Box rest. The next step is box rest in a clean, dry stable. Your vet may also prescribe antibiotics. Check out our tips on how to keep your horse entertained on box rest.

Why is it so important to monitor a horse’s skin?

‘Your horse’s skin is the largest organ in his body,’ Gil says. It’s his first defence against moisture, abrasive substances such as dirt and grit, parasites and bacteria, so problems are common. ‘Keep in mind that, depending on the skin condition, it can be very painful for your horse,’ Gil advises. ‘And, as a condition worsens, it can lead to a secondary infection that causes additional stress for your horse. However, the right treatment can turn things around quickly.’