Cellulitis in HorsesBy Kentucky Equine Research Staff · August 23, 2015
Cellulitis is a bacterial infection of subcutaneous connective tissues. In horses, cellulitis causes pain, inflammation, and often lameness.
The condition is often initiated when a wound—even a minute one—creates an opening for bacteria to enter the body. Scar formation and other healing processes may constrict the flow of blood and lymphatic fluid to that region. Horses with poor lymphatic circulation or blood flow and horses with insulin resistance seem to be at the greatest risk. In essence, compromised immunity is the likeliest predisposing factor.
The first signs of cellulitis are heat and painful swelling. These symptoms quickly worsen, often leading to a fever and discharge from the infected area. If cellulitis develops on a limb, extreme inflammation or swelling may cause lameness. A majority of equine cellulitis cases are found on hind legs, though researchers have yet to identify a specific reason why these limbs are more predisposed.
Common treatments for cellulitis include nonsteroidal anti-inflammatory drugs, hydrotherapy, antibiotics, and exercise to promote normal blood flow. Some veterinarians will remove fluid from the affected region and culture it to identify the type of bacteria present in the connective tissue. Once the offending microorganism has been identified, more specific antibiotics can be administered.
Likelihood of recurrence depends largely on the individual. Some horses have a single bout of cellulitis and then are never again bothered by it. Others, though, have recurring flare-ups after the first infection. For horses that have been diagnosed with cellulitis previously, it is important to watch them closely to make sure all injury sites—old and new—are kept as clean as possible.
Cellulitis is dangerous because it progresses quickly and causes serious damage. Thoughtful hygiene practices, however, will help keep harmful bacteria at bay.