#AskTheVet with Dr. Megan Hays

Question:

What exactly is cellulitis? Can a horse have chronic cellulitis? What is the best way to treat it?

Answer:

Cellulitis is a bacterial infection of the skin and tissue layers below the skin. In horses, limbs are most commonly affected and present as a sudden onset of mild to severe swelling with warmth and pain to palpation of the limb. Fever and lameness are common with cellulitis. Horses may be so painful that they are reluctant to move at all, making it important to have your horse evaluated by a veterinarian in order to rule out other potential injuries or causes of lameness. While cellulitis is seen all year round, it is particularly prevalent in wet months.

There are many different causes of cellulitis including decreased lymphatic drainage, pastern dermatitis, or wounds that serve as an entry point for bacteria to enter the underlying tissues. As such, treatment is aimed at addressing the inciting cause of cellulitis as well as the infection itself. Treatment strategies include combating the infection with antibiotics, controlling discomfort with anti-inflammatories, and reducing the swelling using local cold therapy such as ice boots or cold hosing, and application of compressive sweat bandages on the affected limb. While it may be uncomfortable for many horses to move with cellulitis, turnout and handwalking are important factors in helping to reduce the swelling in a timely manner. In severe or persistent cases, additional treatment therapies including hospitalization may be necessary. 

It is not uncommon for horses that develop cellulitis to be more prone to have recurring bouts in the future. Keeping your horse’s legs free from dermatitis or other skin conditions, decreasing risk of trauma to the limbs, and keeping the limbs dry after bathing and turnout are all good preventative measures. Occasionally, one cellulitis bout may become a chronic condition for the horse. Due to the sudden onset of severe swelling, horses may develop lingering inflammation within the lymphatic vessels in the leg, causing decreased lymph drainage from the leg resulting in a chronically thick or swollen leg even after the pain, heat, and infection are cleared. Your veterinarian will help assess the extent and possible causes of your horse’s cellulitis and develop a treatment plan for each individual case.