It's the old good news/bad news scenario; here's a clip from a roundup of winter horse health observations for the past few months published in this week's Horse and Hound, the British weekly horse newspaper.
Peter Slater MRCVS, from Liphook Equine Hospital in the south of England comments: "The warmer weather this winter has meant less laminitis cases, but much more mud fever. I've seen some quite nasty cases."
Mud fever is directly related to the weather; the wetter it is, the worse the condition, acccording to Horse and Hound veterinary editor Karen Coumbe MRCVS, who adds that is not a single disease, but a collection of clinical signs ranging from a few scabs to cracked heels and sores, which in turn can produce infected legs.
Mud fever has a variety of causes, but can usually be blamed on bacteria infecting chaffed, waterlogged or otherwise damaged skin. Horses with white legs and pink tender skin underneath seem to be the most susceptible.
Hoofcare & Lameness published an in-depth special section on "mud fever" a few years ago, including mite infestation and pemphigus as problems that affect the lower leg; the section is available on cd-rom, or you can order the complete issue, which includes Michael Wildenstein's thesis on white line disease and articles on canker, spider bites, etc. We are doing this to make available articles that can then be printed out and distributed to clients. Email email@example.com to place an order. Other back issues, which have been out of print, are now available on cd-rom as well.