Greasy heel, scratches - in Dutch language called “mok”

Greasy heel is an umbrella term for various forms of skin irritation and inflammation in the pastern cavity (the back area of the leg just above the hoof). These skin irritations and inflammation may also spread to the rest of the leg.  Greasy heel can be very stubborn and sometimes brings the owners to despair, partly because it is coming back again often.

Usually you see problems in the late summer and autumn, but some have it the whole year. Although all breeds can get greasy heel, the disease is more common in horses with big feathers, like Friesians.


Types/stages of greasy heel:

  • “Zomermok” is probably a combination of the skin irritation and influence of "toxic" substances in the grass with too much sunlight in the summer.
  • Dry greasy heel - skin in the pastern is showing signs of redness and flaking.
  • Wet greasy heel - the skin is thickened and there is some moist under. Coming off crusts are leaving gaps.

The causes of greasy heel

Greasy heel is called multifactorial disease. This means that there can be many causes which often occur together.
List of common causes:
  • Outside influences for example sand and mud, dirt, a damp and filthy stables, irritating substances into the soil or in the bedding, urine, diarrhea, a wet meadow, insect bites.
  • Bacterial infections and  fungal infections usually accompany the greasy heel.
  • Mange Mites (parasites) - they’re nesting preferably in the warm, moist environment of the pastern.
  • Excessive washing of the legs. The protective layer of the skin (sebum) is thus removed. The dry skin may burst prone to infections.
Other possible causes:
  • Liver problems
  • Allergies
  • A diet rich in proteins or a hypersensitivity to certain substances in the diet such as clover, alfalfa, molasses.
  • Hypersensitivity to certain irritants, such as care or cleaning.
  • Hypersensitivity to bright sunlight.
  • Reduced resistance of the horse.
  • Even horses that are on stand are often prone to greasy heel. Probably because these horses have no movement and the circulation in the legs is very bad.


  • Redness, scales, scabs and sometimes splits in the pastern cavity. On this ground various pathogens often develop.
  • The skin is thickened in some cases significantly.
  • The affected area is very sensitive and painful.
  • Itching (often it is an indication of mites). This is expressed in stamping feet on the ground.
  • Lameness.
  • Sometimes the whole leg is thicker.
Greasy heel sometimes affects the subcutaneous tissue and lymph vessels may also become infected. This is called lymphangitis. The bottom part of the leg is thick, hot and painful and the horse gets a fever.


There are dozens of ways to deal with greasy heel, ranging from washing with ointments to heavy antibiotics, of every day cleaning, to remove crusts, as well as alternative methods like homeopathies and herbs. This is how a treatment can be difficult. It’s hard to say what helps the best, it also varies from horse to horse. The important thing is the treatment must be addressed to particular case and horse. It is wise to ask veterinarian for a skin scrapings and diagnose them under the microscope. It can show reasons of greasy heel more precisely and allow you to adjust treatment.

Some ways of dealing with greasy heel:

  • First it is important to keep legs clean and dry and if necessary shave the pasterns.
  • Wash with mild antibacterial shampoo or soap (never bring shampoo directly on the wound but thin some shampoo with lukewarm water). It is better to wash with shampoo/soap without iodine because  some horses exhibits hypersensitivity to it.
  • Remove loose crusts. This is necessary for good skin penetration with the ointment. Remember to soften the crusts before removing and do this gently! You can soak them with cod liver oil or other oily ointment (e.g. aloe vera oil or neo-cutigenol ointment). Smear ointment generously on the crust (thick layer) and put a soft bandage (you can leave it over the night).
  • Use a drying or greasy or anti-inflammatory ointment. Discuss with your veterinarian what is the best ointment in your situation. Here the hygienic work is important (clean hands with clean, disposable gloves). In severe cases, the best result is obtained by treatment with well-fitting ointments that contain corticosteroids against the inflammation and/or antibiotics against bacterial infections. Parasite or fungal products may be added to the ointment if needed. Remember - it makes no sense to continue with an ointment if no result is achieved after several days.
  • Give your horse enough exercise if there is no lameness and pain. This stimulates circulation and promotes healing.
  • Veterinarian may use strong antibiotics and anti-inflammatory medicines when the legs of the horse are very thick and there is extensive skin damage. Painkillers are also often advised as the horse suffers greatly.
  • With “zomermok” it is wise to avoid sunlight. Occasionally, a sun cream with a very high protection can be helpful.

Other actions you can consider:

  • Analyze the food ration of the horse and make sure he doesn’t get too much proteins. Always change the food gradually.
  • You can support the horses body from inside (using products supporting cleaning the body and circulation of the substances). Organic sulfur and anti - oxidants seems sometimes effective.
  • Avoid letting the “greasy heel sensitive” horses on the morning dew.
  • Provide good stall bedding without too much dust. Sometimes good shavings are better than bad straw. Clean and airy stables are desirable.
  • Remember about deworming horses and cleaning stables and pastures with anti - parasites chemicals.
  • Homeopathic remedies as plumbago, marigold, pepper tree as an alternative teraphy.


After reading the text above it is clear that a dry environment is very important. Keep at least the legs of the horse dry and use a good bedding in the stable.

Always consult your veterinarian in matters regarding the health of your animals!!

Similar diseases:

  • Pastern dermatitis
  • Lymfangitis (lymph vessels inflammation) known as Fat/Big Leg Disease

LymphangitisPastern dermatitis and lymphangitisPastern dermatitis

Interesting website (in Dutch)

© Copyright by Izabela Grzonka