Winter Series: Mud Fever
Mud fever, also known as greasy heel syndrome but correctly termed pastern dermatitis, is an infection of the skin usually of the pastern.
The bacteria causing the infection can be from the environment or living on the skin itself and will gain entry due to an injury to the skin surface. It more commonly affects white socked legs, as the skin’s immune function of these areas is reduced. In minor cases it may present as just a few scabs, however, it can spread above the fetlock, occur concurrently with cellulitis, or leg filling, and be openly bleeding.
Although it can have a typical appearance sometimes a vet visit is needed to rule out other conditions and to identify predisposing factors.
The skins integrity is weakened by continuous wetting of the skin and rubbing from mud meaning it is a problem commonly seen in Winter. However, it may not just be wet and muddy conditions that are causing the problem……..
- Lymphoedema: this is typical of cob type or draught breeds. Lymph fluid circulates around the body carrying nutrients in lymph vessels. The lymph vessels in these types seem to be less effective in circulating blood in the lower limbs which leads to accumulation of fluid and skin thickening.
- Leucocytoclastic vasculitis: this is an immune mediated condition whereby blood vessels become damaged. Personal experience shows it occurs more commonly on the outside of white pasterns.
- Photosensitisation: this is caused by either liver disease or allergic reaction meaning the horse doesn’t deal with chemicals that react with light meaning that when the horse is exposed to UV radiation (sunlight) it becomes sunburnt.
- Feather mites/ Chorioptic mange: Chorioptes mites causes itchiness of the lower limbs. This can lead to self trauma and wounds allowing skin infection.
To rule out these conditions it may be necessary to take blood samples or biopsies to determine if one of these are involved.
In order to treat Mud Fever you may need to treat the underlying cause. Sometimes a thorough antibacterial cleaning and removal of scabs is needed, under sedation, so that topical antibacterial, steroidal and protectant creams can be applied directly onto the damaged skin. In some cases when associated with cellulitis or more widespread infection of the leg systemic antibiotics may be needed.
The deliberation is always; do you wash the mud off your horses legs or do you brush it off when dry ?? In our opinion neither is superior. If you are to wash your horses legs they need to be thoroughly dried and if there is already some mud fever present avoid wetting the leg further.