Grease Heel

...and on the eighth day God created the horse in perfect image, to romp, graze, gallop, play and make manure wherever it darn well pleases, in divine grace.

Grease Heel, also known as Mud Fever and Dew Poisoning, is a chronic skin disease, appearing as dermatitis on the back surface of the horse’s pastern.

It can be bacterial or fungal in nature. (1) Usually the hind legs are affected more often than the front ones. Horses that have long hair or feathers, or heavy horses with thick hair are the most susceptible.

Draft Horses seem particularly susceptible, with their stocky, feathery legs and heavy builds.

Constant moisture, such as when horses are left outside in fields year-round, constant mud and water, or filthy stable conditions are the cause of Grease Heel. Constant leg wraps can retain moisture, also.

Oozing serum and thick, crusty formations, along with redness and irritation on the skin are the signs of Grease Heel.

It can go undetected for a long time, especially if the horse is out in the field, with a run-in shelter. If left untreated, the sores spread.

Eventually, it becomes very thick, cracks open and the hair falls out.(2)

The skin is sensitive, itchy and puffy, and can become mushy and soft. A stinky smelling substance forms as the sores begin to ooze.

The skin can become hard and thick in chronic, severe cases, and in rare cases the swelling can be quite large. In the severe cases, cracks appear in the skin which are followed by the formation a various sized lumps of granulated tissue known as grapes, due to the surface formation of proud flesh, which has the appearance of a bunch of grapes.(3)

The horse can become lame.

Chronic Grease Heel leaves the pastern area lumpy and hard, and susceptible to re-infection.

When Grease Heel is discovered, remove the horse from the wet field or mud lot, or clean the stable and use dry, bagged pine shavings for bedding.

Clip the hair off of the affected area and just beyond, to determine the scope of severity. Soaking to remove crusts may be necessary, using a mild soap and warm water. Use topical antiseptic cream, such as chlorhexadine or Ichthamol for anti-bacterial or miconazole for anti-fungus.(4)(5)

Fungus is tricky; keep treating for as much as 10 days after symptoms clear, or it may return.

Recent studies have shown a new product, known as Kunzea Oil, from Tasmania, with 20% Kunzea Oil, and salicylates, sulfur and zinc oxide, can eliminate Grease Heel in 7 days. This was in trials with 3 horses. (6)

In severe cases, call the Veterinarian. A topical antibiotic-corticosteroid ointment will help to eliminate the infection and inflammatory reaction. An oral antibiotic may also be prescribed. If grape masses are present, the Vet may sever them with a surgical blade or a laser, after disinfecting the area, the same as proud flesh would be removed from any other part of the horse.(7)

This will aid in healing.

Keep the horse out of the mud and wet, everyone knows that with good horsekeeping the drier the better.

I once had a Belgian mare that got Grease Heel. It's messy; I had to keep the pasterns shaved and had a heck of time getting rid of it.

The information included in this article is meant as a guideline and not Veterinary analysis. Call the Vet for consultation if you suspect your horse has Greasae Heel.

More next week. Signing off for this time to the immortal words of Roy Rogers and Dale Evans, “Happy Trails to You.”

1-4, 7: “Horseman’s Veterinary Encyclopedia,” by Will A. Hadden III, DVM

5, 6: Wikipedia