Mud fever and how to deal with it
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 is a skin infection that is caused by a mixed infection with a range of bacteria and fungi. It results in swelling, soreness, scabs, discharge and splits in the skin. As it progresses it can cause the whole limb to swell and lameness.
What causes it?
The infection takes hold when the skin surface becomes damaged. Typically wet conditions cause irritation to the skin. Horses with feathered legs are typically at risk as the hair will trap moisture against the skin. Abrasions and scratches also allow infections to take hold. The use of oils, grease or ointments, once an infection has started, will generally worsen the condition.
What are the problems with treating it?
Traditionally antibiotics have been used to treat the condition. Unfortunately they do not treat the fungal part of the infection. The use of antibiotic creams is unlikely to kill all the bacteria, especially those deeper in the tissues. Systemic antibiotics (those given by mouth or injection) have to be given for a protracted course (e.g. four to six weeks) to be completely effective in skin infections and again will not treat the fungal infection. There are also increasing problems with some of the bacteria being resistant to different antibiotics.
What can be done?
We are now using a topical treatment involving the use of silver sulphadiazine. The protocol for treatment is illustrated in the table below. Initially any scabs and crusts are removed by bandaging with a hydrogel (e.g. Vetlintex) followed by gentle washing. This is then followed by dressing the affected areas with the silver sulphadiazine cream (Flamazine). Although this does involve bandaging and stabling the horse, it has been a very effective treatment. In cases where there is a lot of exudate (fluid) coming from the wound it may be more suitable to use a silver impregnated dressing (Acticoat). This dressing can be left on for 3 to 5 days. Both these treatments are effective against both bacteria and fungi and do not have the resistance problems associated with antibiotics.
|Dry Scabby Form||Moist Exudative Form|
|Apply Vetlintex gel to affected areas and dress with a non-adhesive pad (Advasorb), Softban and Vetrap for 12 to 24 hours. Gently remove the loosened scabs with a swab and dilute hibiscrub solution. Dry thoroughly afterwards.||Apply Vetlintex gel to affected areas and dress with a non-adhesive pad (Advasorb), Softban and Vetrap for 12 to 24 hours. Gently remove the loosened scabs with a swab and dilute hibiscrub solution. Dry thoroughly afterwards.|
|Soak a nanocrystalline silver dressing (Acticoat 7) in water for several minutes. Apply the blue side of the dressing to the affected area. Cover the dressing with an Advazorb pad, Softban and Vetrap.||Apply with silver suphadiazine ointment (Flamazine) and cover with Advazorb, Softban and Vetrap.|
|Leave the dressing in place for between 3 to 5 days depending on the amount of exudate.||Change this dressing after 24 hours and remove any scabs with a swab and hibiscrub solution. Dry thoroughly afterwards.|
|The dressing may need to be repeated but this should only be on a veterinary surgeon’s advice.||Change the dressing again after a further 48 hours. A further dressing change after another 48 hours may be required if all the lesions have resolved.|
It is essential that the affected limb is dried thoroughly at dressing changes or it will cause the treatment to fail. This regime has been extremely effective in treating cases of mud fever: where it fails, there is usually a problem with the application or bandaging. As both these products contain prescription only medications we will need to see your horse to assess which treatment option is most suited to your horse.