By Dr Carly Garling
Greasy heel or pastern dermatitis are terms used for a collection of conditions that affect the skin of the pastern in a horse. Bacteria, fungi, parasites, sun exposure or allergies can cause this condition that presents as scabs, crusting or ulcers with various distributions on the pastern, but most commonly in white legs on the back of the pastern.
It is important to gain control of this condition, as it can be painful and quickly progress to whole limb involvement (cellulitis).
To get on top of Greasy Heel, you need to understand why your horse is suffering so you can treat the condition now and place management practices to prevent this from happening again.
Physical factors include insect bites as well as chronic exposure to mud/wet grass which will lead to traumatised macerated skin.
Horses with poor immunity may not be able to fight off skin infections as well as other horses can. Poor immunity may be from Pars Pituitary Intermedia Dysfunction (Cushings), malnourishment or parasite infection.
If you notice your horse has irritation wounds or scabbing on all four pasterns, it could be because they are suffering from contact allergies from plants in the paddock, or the type of bedding in the stable.
Exposure to the sun will only occur in areas with white markings (unpigmented skin) most commonly on the outside of the leg. You will notice hair loss and scabbing. This can also be caused by liver disease or ingesting a photosensitizing agent such as Saint John’s Wart, Clover, or Perennial Rye Grass.
Once the skin is compromised by one of the above processes, opportunistic bacteria, mostly Dermatophilus Congolensis or Staphylococcus Aureus, will cause a secondary infection. Therefore, we need to treat the infection as well as control the underlying cause so that it does not recur.
Treating An Active Infection
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