As horse owners/riders it’s essential for us to always be vigilant for signs of ill health in our horses. During the autumn and winter months there are certain conditions that are more commonly found due to the wetter weather and colder temperatures. One of the most common conditions is mud fever.  We’ve taken a look at how to identify it and how it’s treated. 

Mud fever, also known as ‘greasy heels’ or ‘cracked heels’, is properly named pastern dermatitis. It refers to a range of equine skin reactions which are primarily caused by an infectious agent which thrives in muddy, wet conditions (dermatophilus congolensis) and is able to stay dormant in the horse’s skin. This infection will then become active when the skin has been compromised through damage or injury – cuts, wounds, bites, sores or prolonged periods of wetting all compromise the skin’s ability to keep out infection. 

Causes of mud fever: 

  • Standing in deep mud or soiled bedding for long periods of time 

  • Prolonged spells of damp, mild weather 

  • White limbs/patches on the body are typically more prone to mud fever  

  • Excessively washing legs and not fully drying them after, particularly with warm water 

  • Excessive sweating under tack and rugs 

  • Chaffing, sores and rubs from boots or bandages 

  • Generally unhealthy skin or low immune system 

Signs and symptoms 

As with all illnesses and conditions, it’s best to catch mud fever early if you can. Check your horse’s legs carefully and regularly from the beginning of the mild, damp weather – normally from early October onwards. Though horses with white limbs are more prone to mud fever, it can affect any horse and may be more difficult to spot in horses with dark legs. 

Early signs of mud fever are matted areas of hair containing crusty scabs on the backs of the heels and pasterns. Beneath the scabs will be small, circular moist lesions, and the skin (particularly noticeable on white limbs) will appear red, raw and inflamed. Mud fever on the front legs could often be easily mistaken for overreach injuries. There may also be some heat or swelling in the limbs, with the horse showing signs of pain/discomfort. 

As the condition develops and the infection worsens it’s typical for the horse to start losing hair in the affected areas. There may be some creamy white, yellow or green discharge depending on the how far the infection has set in. Lameness is possible, and in severe infections the horse may have a loss of appetite and show signs of lethargy and depression. 


How to treat mud fever 
The most important part of managing mud fever is to keep the skin clean and dry, which might only be possible by keeping the horse stabled.  

Removing the scabs in order to treat the infection is essential, as the treatment has to reach the infection beneath the scabs. This can be painful for the horse, so sedation may be required for safety. If any of the scabs are particularly tough, they may need to be soaked or poulticed first.  

Once the limbs are free from scabs, they should be washed using either mild disinfectant, iodine wash, surgical scrub or medicated shampoo then rinsed well. They should then be thoroughly dried with clean towels. There are various creams and ointments on the market that can then be applied to help encourage healing – look for products containing zinc, castor oil and lead acetate, or anti-inflammatories. 

This process might need to repeated multiple times before the legs heal – in severe cases it can take several weeks for the horse to fully recover and they might need veterinary intervention. 

Preventing mud fever 

  • If the field is particularly muddy, or the horse is unable to stand anywhere dry, consider bringing in overnight/for a few hours to give the legs a break from being wet 

  • For stabled horses, ensure the bedding is as clean and dry as possible 

  • Resist the urge to wash mud off the legs – instead wait for it to dry and brush it off 

  • Ensure the legs are clean and dry before applying boots or bandages 

  • Consider using topical barrier creams prior to turnout or exercise 

  • Waterproof turnout chaps or boots are a fantastic investment for horses prone to mud fever - we recommend either the Woof Wear Mud Fever Turnout Boots or the Equilibrium Close Contact Equi-Chaps

  • Consider feeding nutritional supplements that promote healthy skin 

  • Rotate paddocks to avoid poaching, or fence off the worst areas 

  • Avoid scrubbing of overly-grooming the legs, particularly if wet 

Always consult your vet if you are worried about injury or illness to your horse.