Pyoderma is a bacterial skin infection that drains pus. Many cases are the result of self-mutilation. When a horse rubs or bites at a persistent irritant to its skin, the skin becomes infected. Always look for another skin disease before concluding that pyoderma is the only problem the horse has.
CELLULITIS is an infection of the deep layer of the skin. Most cases are caused by puncture wounds, scratches, and cuts. Horses are aprticularly prone to such injuries. Many wound infections can be prevented by proper early treatment of wounds.
Signs of cellulitis are pain (tenderness to pressure), warmth (the skin feels hotter than normal), firmness (not as soft as normal), and change in color (it appears redder than normal).
As infection spreads out from the wound, you may feel tender cords which are swollen lymphatic channels. Regional lymph nodes may enlarge. This is a stage beyond cellulitis and is characterized by two disease (ulcerative lymphangitis and malignant edema).
A skin ABSCESS is a localized pocket of pus. Pimples, furuncles, and boils are examples of small skin abscesses. An abscess is fluctuant and feels like fluid under pressure.
The following skin infections are of particular importance:
FOLLICULITIS ("Summer Rash"). This is a hair-pore infection nearly always caused by a Staphylococcus bacteria. It tends to occur in hot weather as a consequence of excessive sweating and friction to the skin from ill-fitting tack. Small pimples appear, usually at points of contact in the saddle or harness areas. These pimples enlarge and form pustules. The pustules rupture and exude pus. Crusts form and the hair becomes matted.
Folliculitis can be prevented by good hygiene, such as brushing and cleaning the skin and coat after workouts, and using clean dry blankets beneath saddles.
FURUNCULOSIS. This is a deep-seated hair-pore infection with draining tracts and patchy hair loss. It is a progressive form of folliculitis and more difficult to treat.
Tail Pyoderma. This condition begins as an itchy skin disorder caused by mange mite or pinworms. As the horse scratches, rubs, and abrades the skin of its tail, secondary staph infection occurs and pustules develop. The ailment is complicated by furunculosis, and by abscesses that rupture and drain in an unending cycle. Hair is lost on the top of the tail. Treatment is most difficult.
TREATMENT OF PYODERMA
Any underlying itschy skind disorder should be treated to eliminate rubbing, biting, and self-mutilation.
Localize the skin infection by clipping away the hair and applying warm soaks for 15 minutes 3 times a day. Saline soaks, made by adding a cup of Epsom salts to a gallon of warm water, make a good poultice. Daily Betadine scrubs help to loosen scabs and promote cleanliness. Topical antibiotics such as nitrofurazone or Triple Antibiotic Ointment are of value and should be applied 2 to 3 times a day.
Oral or injectable antibiotics are used to treating wound infections, cellulitis, abscesses, furuncles, and tail pyoderma. Most skin bacteria respond well to penicillin, oxytetracycline, or trimethoprim-sulfadiazine.