Cellulitis is characterized by inflammation and infection within the skin and connective tissue. It usually results from a wound that allows bacteria to penetrate the protective barrier of the skin surface and become seeded within the subcutaneous tissues. Often the initiating cause is never able to be identified, as it may be too small to visualize. Common skin conditions, particularly pastern dermatitis (or “scratches”) can be precursors to cellulitis. Any region of the body can be affected, but one of the most common manifestations of cellulitis is in the distal limbs, more commonly the hind limbs. When affected, the limb will become edematous, warm and sensitive to palpation, often causing marked lameness and even fever. The limb can rapidly become two or three times its normal size, and serous drainage from the skin may be present. Accompanying systemic signs include elevated heart and respiratory rate as well as inappetence. Successful treatment is greatly influenced by early recognition of signs and prompt initiation of treatment. Recurrence can also be an issue even after aggressive and timely treatment, especially in more severe cases of cellulitis.
Mainstays of treatment include systemic anti-inflammatories (Bute or Banamine), systemic antibiotics, and aggressive local therapy. Local therapy is a very important aspect of treatment and includes a regimen of cold hosing and placement of DMSO/Furacin sweats wraps. Often the sweat wrap is placed overnight, with dry standing wraps during the day to allow frequent hand walking, as motion is beneficial to increase circulation within the distal limb. Antibiotic choice can vary based on the severity of the cellulitis, with aggressive intravenous treatment being required in some cases.
Cellulitis can be difficult to treat and, due to the potential of recurrence, prevention is important. Any wounds noted on your horse should be kept clean and dry, with veterinary evaluation sought if there are any concerns. Similarly, diligent treatment of skin conditions, particularly those on the distal limb, will help keep cellulitis at bay. Early detection of cellulitis aids in increasing the success of treatment and helping to avoid a recurrent problem in the future.