Cellulitis is most common in a hind limb, but it can also occur in a front leg or on other parts of the body. “The classic form of cellulitis is unilateral, affecting just one limb, but it can affect multiple limbs,” says Fogle. Here are the common signs:
• Swelling that is dramatic and appears suddenly. “The leg is usually diffusely enlarged, sometimes all the way from the foot up to the stifle or beyond, and the typical case is generally swollen from at least the foot to the hock,” says Mudge. The leg may be two or three times larger than normal, and the swelling will be firm to the touch.
• Severe pain. “These horses are generally very lame, but often the pain occurs when advancing the limb rather than from standing on that leg; it’s difficult or painful to move the limb,” Fogle says. “Generally, the horse will bear reasonable weight on the affected limb when not being asked to move, compared to a non-weight-bearing lameness that is commonly seen with a fracture or a joint infection.”
• Heat. “The leg is usually very warm and painful to the horse if touched,” says Mudge.
• Fever. The horse’s temperature is likely to be elevated, and his heart rate may be increased. His overall attitude may be dull, and his appetite low.
• Wetness on the surface of the skin may be noticeable, especially if the swelling is dramatic. “Depending on how severely swollen it is, the leg may be oozing serum, weeping through the skin,” says Mudge. These breaks in the skin may have been caused by the initial trauma, or the skin may be so overstretched that the yellowish serum seeps out.