Mud fever is a perennial problem. Traditionally it has been associated with wet muddy conditions seen in the winter but we often see cases throughout the year.
What is it?
Mud fever, also known as pastern dermatitis or ‘cracked heels’ is characterized by scabs and sore on a horse’s legs. It often affects pink skinned areas and may be noticed as red, sore areas of skin that may be weeping, or lumpy patches often on the lower limbs, although any leg can be affected.
Left untreated, mud fever can develop into costly complications if an infection travels up the leg through the damaged skin, causing a painful condition known as cellulitis.
What causes it?
This painful skin condition is caused by bacteria that live in the environment, Dermatophilus congolensis. Wet, damaged skin provides an ideal moist environment for the bacteria to grow. Once an infection develops, this can cause the skin to be very itchy and the horse may scratch their legs, damaging the skin’s protective barrier further and promoting penetration of more bacteria into the skin.
Horses with hairy feathered legs are typically at risk as the hair will trap moisture against the skin. The use of oils, grease or ointments, once an infection has started, will generally worsen the condition.
How can it be prevented?
As with most things, prevention is better than cure and there are various management techniques that can be employed to prevent mud fever. An obvious solution to controlling mud fever is avoiding wet, muddy conditions, so keeping gateways and shelters mud free (try putting down wood chip in high traffic areas) and bringing horses off muddy pasture is preferable. Hairy legs can act as a trap for mud and create the perfect warm, moist conditions that the bugs thrive in.
Clipping of hairy legs can be very useful as it facilitates keeping the legs clean and dry, and provides better visibility so any lesions are likely to be noticed and treated earlier.
Keeping legs clean and dry is imperative. Wet, macerated skin provides the perfect conditions for the bacteria to grow and multiply so it is no good religiously washing your horse’s legs clean everyday unless they are thoroughly dried too. Paper towels, old bath towels and even using a hairdryer on a cool setting are good ways of getting legs dry after gentle cleansing with water or a weak hibiscrub solution.
How can it be treated?
Good management practices and vigilant checking of the legs before lesions develop is often all that is required to keep mud fever at bay. The use of oils, grease or ointments is not recommended as they can actually exacerbate an infection. However, certain preparations that are available on veterinary prescription are highly effective at treating mud fever, including a silver based cream called Flamazine. Although this does involve bandaging and stabling the horse, it is a very effective treatment. Certain cases of mud fever may require systemic antibiotics. These treatments contain prescription only medications, so a veterinarian will need to see your horse to assess which treatment option is most suited to your horse.