British winter weather means that when kept out, horses’ feet and hooves become waterlogged in the inevitable wet and mud, which can cause frustratingly frequent skin problems like mud fever and rain scald.
Skin disease has been reported as a common problem in the annual Blue Cross Equine Health surveys, seen even more frequently than lameness. Sweet itch (the top summer nuisance) and mud fever (the top winter worry) accounted for nearly half (40%) of all the skin diseases recorded.
Horse skin is amazingly delicate and when waterlogged in wet weather it becomes more susceptible to damage and infections — grooming or even being worked in a sand school can cause micro-abrasions, which let bacteria in.
The horse’s ability to ward off infection is reduced by continuous wetting and sweating, as well as standing and being ridden in cold wet muddy conditions, hence the name ‘mud fever’. The proper name is pastern dermatitis, reflecting the range of skin reactions that affect the lower limbs due to different skin irritants, such as bacteria, fungal infections and mites.
Mud fever is similar to a person having chapped hands or lips — the horse’s skin can become very inflamed and sore. Pink skin under white hair is more sensitive, but dark skin can be affected too. Whatever the trigger, the skin will become red, crusty and scabby and the legs will become swollen. Sometimes the hair will fall off. In severe cases the horse will be lame. Long, ‘feathered’ hair can acts as a protectant, waterproofing layer, unless it gets completely waterlogged or is infested with mites.