Cellulitis is a serious condition that is caused by infection of the limb by bacteria. Often the cause of the infection cannot be found, but it is commonly thought to occur secondary to a tiny puncture wound of the lower part of the limb. Your horse will have hot, painful, generalised swelling of the lower part of the leg. Pitting oedema may also occur, which is seen when pressure is applied to the lower limb and an indentation remains. Your horse may be lame on the affected limb, and can be generally unwell with a raised temperature.
Your vet must be called immediately, as this condition can be very dangerous if not treated rapidly.
Anti-inflammatory drugs and antibiotics will be prescribed by your vet. Cold hosing and bandaging of the affected area are usually also recommended. Most horses respond well if the treatment is prompt enough. However, in extreme cases horses can lose skin in the affected area, or develop laminitis in the opposite leg due to increased weight-bearing on the unaffected limb. After an episode of cellulitis the limb may not return to its original size and horses who have had cellulitis once are more prone to a recurrence.