WHAT IS MUD FEVER? Mud fever, also referred to as scratches, greasy heel, or pastern dermatitis, describes an inflammatory and often painful condition that usually affects the lower limb region of horses.
It is likely to develop during particular times of the year or during certain weather events; more commonly seen during periods of wet weather where the horse is exposed to waterlogged soil and muddy surfaces, as well as damp pasture and bedding, for prolonged periods of time.
SIGNS & SYMPTOMS OF MUD FEVER Equestology Sport Horse Science (2018, para. 2) writes that “clinical signs can range from inflammation, hair loss, scabs, cracked and ulcerated skin, to granulation tissue, discharge and generalised swelling of the lower limbs and associated lameness.”
Visible symptoms of mud fever may be similar to other skin conditions caused by allergies which can result in a misdiagnosis, highlighting the importance of performing a thorough examination of both the horse and the surrounding environment.
Horses with non-pigmented skin, such as those with white ‘socks’ on their legs, and horses that have feathering at the fetlocks, appear to be the most commonly affected when it comes to mud fever (Canberra Equine Hospital 2020).
The long and thick fetlock hair generally seen in heavy breeds can hold moisture and keep the skin damp which reduces skin integrity and provides an opportunity for bacteria and fungi to accumulate and take hold.
The pathogens that are most commonly linked to the development of mud fever in horses include bacteria such as Staphylococcal spp. And Dermatophilus Congolensis, moulds and fungi that produce toxins called Mycotoxins, and organisms such as mites which are more commonly seen in feathered breeds such as Clydesdales and Friesians (Equestology Sport Horse Science 2018).
Mycotoxins are a particularly common cause of mud fever in horses when they are housed in hot, humid, or moist climates; which are the optimal habitat for Mycotoxins to thrive.
Mycotoxins binders (such as those found in CEN XtraBalance) can be extremely useful dietary additives to alleviate the symptoms of Mycotoxicosis. Less common causes of mud fever include fungal infections of the skin such as Dermatophytosis, worm larvae infestations, vasculitis, liver disease, pemphigus foliaceous, and coronary band abnormalities (Equestology Sport Horse Science 2018).