Guide to Mud Fever

Posted on October 10, 2022 by Categories: Kyowave
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Mud fever is a stubborn, common and very uncomfortable condition. It tends to affect horses during the wet winter months, but it can also occur in Spring if conditions are wet enough. Read our guide to learn about how to recognise, treat and prevent mud fever.

What is Mud Fever?

Mud fever is a general term for a skin infection, usually affecting the horse’s lower legs, which may be caused by bacteria, fungus or parasites. Other names include pastern dermatitis, greasy heels and cracked heels. 


Mud fever is characterised by sore, scabby skin on the lower legs. Early signs include reddened skin and hair loss. As the condition progresses, there may be horizontal folds in the skin and pus, which can make the skin look greasy. Mud fever commonly affects the pasterns and fetlock area, but can extend up the cannon bone to the knees or hocks. In severe cases, the whole leg may become swollen and painful, and the horse may go lame. 

The condition can also occur in other areas. It sometimes affects the skin on the horse’s back, and this is known as rain scald. Rain scald tends to occur during prolonged spells of wet weather, particularly if the horse does not have adequate access to shelter or is left standing in a wet rug. 

Treating Mud Fever

There are a number of treatments for mud fever. Typically, antibiotic creams or ointments are used in order to kill off the bacteria, fungi or parasites causing the infection. This is combined with keeping the legs clean, dry and protected from the mud and wet weather. 

Unfortunately, mud fever can be incredibly stubborn to treat and it is often the case that efforts made to treat the mud fever actually run the risk of making it worse. For example, constantly washing the legs and failing to dry them properly causes the skin to weaken. Turnout boots and bandages may rub, which only aggravates the already damaged skin further.

Furthermore, the increasing problem of antibiotic resistance means some treatments are becoming less effective against some bacteria. When antibiotics are used too much or are not used properly, the bacteria can develop resistance and this makes infections harder to treat. 

Preventing Mud Fever

When it comes to mud fever, prevention is far better than cure. The risk of this condition occurring can be minimised by keeping the horse’s legs clean and dry. There are a number of ways in which horse owners can do this:

Allow fields time to rest and recover to avoid them becoming too muddy. This may involve keeping horses stabled for longer periods, rotating the grazing or fencing off areas of the field a bit at a time

Lay down rubber matting or fence off areas that are prone to becoming especially muddy. High traffic areas such as gates, water troughs or feeding areas are likely to get very muddy. Consider placing the hay / feed in a different area each day. 

Keep an eye on your horse’s legs. Take care to avoid anything that might rub, irritate or damage the skin. If you use exercise boots, ensure they are always clean and dry before putting them on your horse. Make sure they fit properly and are not rubbing the skin.

Consider clipping the feathers (or take extra care to keep them clean and dry) if your horse has them. Feathers can act as a barrier to protect the skin from damage. However, they can also conceal symptoms. Either way, feathers should be kept clean and dry and may need to be clipped. 

Keep your horse’s stable clean and dry. Wet, soiled bedding is just as bad as a boggy field and can harbour bacteria and parasites.

Keep the horse’s legs clean and dry. Note that washing the horse’s legs daily, only to turn them back out with wet legs, is likely to increase the chance of mud fever occurring. This is because wet, cold skin is more prone to damage and therefore infection is more likely. Instead, allow the legs to dry before brushing the mud off once it has dried. If you do decide to wash the legs, allow them to dry completely before turning the horse out.

Kyowave: Blue Light Therapy by Cryochaps

At Cryochaps, we are focused on bringing innovative, effective products to horse owners. One such innovation is Kyowave, a boot designed to kill the bacteria that are known to cause mud fever. 

Kyowave works using blue light to destroy the bacteria without the use of antibiotics. It was inspired by the use of blue light in human medicine, as well as the need to tackle antibiotic resistance. Kyowave has already been shown to kill the bacteria known to cause mud fever in studies carried out by the University of Surrey.

If you are at your wit’s end with mud fever, and have tried everything in the book to little or no avail, then it’s time to try something new. It’s time for Kyowave. 

Kyowave is available as a single boot or pair of boots via our online shop

kyowave mud fever therapy boot
Left to Right: Day 0, day 8 and day 17 of using Kyowave.

Note: Seek advice from your vet if you are concerned about mud fever or if you are unsure. This article is not a substitute for veterinary advice or treatment.