Other names: pastern dermatitis, scratches, swamp fever

What is it?
Greasy Heel is an inflammatory condition of the skin (dermatitis) involving the lower limbs, particularly non pigmented skin. Lesions appear as scaling, crusting, erosion and exudation, and can be due to a number of skin conditions. Organisms that most commonly cause Greasy Heel include fungi, bacteria and mites in horses with feathering at their fetlocks.

How does it occur?
A number of environmental conditions can predispose the horse to Greasy Heel, however those horses with white limbs and feathering at the fetlock appear to be particularly susceptible. Conditions favourable for the development of Greasy Heel include:
constant or repeated exposure to moisture eg. swimming, wet bedding, muddy paddocks from wet weather
low heel conformation
insect bites on the lower limbs
abrasions from loose surfaces eg. gravel
These conditions reduce the effectiveness of the skin as a barrier to organisms, allowing them to invade and cause dermatitis.

What does it look like?
Early in the disease, Greasy Heel appears as a mild dermatitis with swelling and reddening of the back of the pastern. Hind limbs tend to be more frequently involved, however lesions can occur on all four limbs. With progression of the disease, numerous scabs and/or crusts may form, causing matting of the hair. If left untreated the infection may extend up the limb and secondary infection may occur, resulting in pus discharging from the area and more severe swelling of the limb.
In horses with feathering at the fetlock, lesions tend to be more severe and occur over a larger area, whilst lesions tend to be smaller in short haired horses.

Is Greasy Heel painful?
In it’s early stages, Greasy Heel is not painful, but may cause some discomfort to the horse. However, if the lesions are not treated and allowed to progress, they may become pruritic (itchy) and lead to scratching, further trauma and lameness.

What can I do, as an owner, to treat Greasy Heel?
The most important aspect of the treatment of Greasy Heel involves identifying and removing the predisposing factor(s) that started the disease.
Once the predisposing factor(s) are removed, steps to reduce and treat Greasy Heel include:

  • Keep lower limbs dry
  • Clip hair and clean the affected areas
  • Soak the affected limbs for 10 minutes with water
  • Remove all scabs with a soft cloth, but DO NOT cause bleeding as this will lead to further scab formation. Scabs may need to be softened before removal using chlorhexidine solution or an iodine soak to prevent this. Other softening agents such as manuka honey or simply warm water may also be used. Once softened, remove scabs by rubbing lightly with either a betadine or chlorhexidine solution, or medicated shampoo.
  • Once removed, hose off solution with water and towel dry
  • Apply antiseptic ointment over affected region, and lightly bandage to prevent contamination and sunlight exposure.
  • Repeat steps 2-5 every one to two days.

Does this condition require veterinary attention?
If Greasy Heel is found in its early stages, the above steps should be followed and any changes noted. If the lesions worsen even with treatment, or any severe signs such as lameness, cracking or bleeding are present, you should seek veterinary advice. The veterinarian may need to assess the horse to direct appropriate therapy such as antibiotics.

How long will it take to heal?
Unfortunately Greasy Heel can be a persistent disease and appear as though it is not responding to treatment. Don’t give up, treatment may need to be continued for weeks and possibly months. If the environment is kept clean, dry and the area is regularly cleaned, improvement should be seen as the disease is self limiting in most horses.

How can Greasy Heel be prevented?
Prevention is the best cure for Greasy Heel. The most important predisposing factor for the development of lesions is a persistently wet and/or muddy environment leading to softening of the skin of the lower limbs. Thus, the best prevention can be achieved by housing the horse in a clean, dry environment. The lower limbs should also be monitored for any signs of dermatitis such as swelling or reddening of the skin so therapy can be started early in the disease process.