Information on Chronic Progressive Lymphoedema (CPL) / Lymphedema, feather mites and associated conditions
CPL or Feather Mites?
Why is CPL so frequently misdiagnosed as Feather Mites Damage?
CPL? Feather mites? … Or both?
Almost every new owner of a CPL horse says one of the following:- “They told me it was mud fever“ “The owner said it was just scratches” “I was told it was feather mites.”
The devastating discovery that they have been unaware of their horse’s condition because of a misdiagnosis or misunderstanding is something owners find very difficult to deal with.
When we talk about feather mites damage, what are we really saying? Essentially that there is scarring, be it from a chronic infestation of mites themselves or the horse self-injuring as a result of the itchiness and discomfort. In normal, healthy draft horses without the genetic predisposition to CPL nothing will ever come of this mites damage. It will sit there on the surface, being perhaps a bit unsightly and maybe the legs take a bit longer to go down after a night in the stable due to the very superficial lymph vessels being affected. But for a horse predisposed to CPL, this mites damage will likely lead to the onset of the disease.
This is why we see some horses with very mild, superficial mites damage that never changes, even into old age. There isn’t usually any oedema present, or if there is it dissipates quickly once exercised, so we know the lymphatics in the affected areas are working well.
But how do we know when this is going to be a horse who develops CPL? Well, we don’t and unless more research goes into finding the genetic cause and a reliable way to detect it in all draft horses, we aren’t going to be able to tell. But what we can do is assume that all horses could develop CPL as a result of this mites damage (or myriad other triggers) and adopt a CPL-friendly routine management protocol.
In some ways it is lucky for horse owners that CPL management can mainly be done at home and without expensive vet bills. There is very little that can be done clinically for CPL horses beyond the occasional need for antibiotics and steroids. But the work of a good, knowledgeable vet is more than just their ability to prescribe – many CPL owners come to the realisation that their horse is affected all of a sudden, often after years of being completely unaware and we are told time and again on a daily basis that they just wish their vet believed them and would be more helpful and supportive.
The onus is on vets now, as CPL cases soar across the UK and USA, Canada and Europe, to self-educate and strive for better service to their CPL patients because this isn’t going away. Infact, with the indiscriminate breeding practices that are rife across the UK currently, particularly in gypsy cobs and the larger Irish cobs, CPL and feather mites are going to become endemic in the breeds very quickly as horses are bred and inbred for more and more mane, tail, feather, weight and bone, without realising the consequences of overburdening a lymphatic system that is already at full stretch.
“C. bovis infestation may affect the progression of chronic pastern dermatitis (also known as chronic proliferative pastern dermatitis, chronic progressive lymphoedema and dermatitis verrucosa) in draft horses, manifesting with oedema, lichenification and excessive skin folds that can progress to verruciform lesions.”
While the scabs associated with mud fever/greasy heel (“scratches”) and feather mites may look similar to CPL sores, they are not the same condition and once we know what to look for the difference is clear. The likelihood of full feathered horses developing mud fever is slim compared to warmblood breeds but not impossible. However chronic mud fever still has the potential to scar and damage the lymphatic vessels, in the same way feather mites can.