Cellulitis is an infection involving the skin and subcutaneous tissue. Most cases are caused by puncture wounds, deep scratches, bites, and lacerations. Cellulitis can often be prevented by properly treating wounds, as described in Wounds.
An area affected by cellulitis will be tender to pressure, feel hotter than normal, not be as soft as it would normally be, and appear redder than normal. As infection spreads out from the wound, you may feel tender cords beneath the skin, which are swollen lymphatic channels. Regional lymph nodes in the groin, armpit, or neck may enlarge to contain the infection.
A skin abscess is a localized pocket of pus beneath the epidermis. Pimples, pustules, furuncles, and boils are examples of small skin abscesses. A large abscess feels like fluid under pressure.
Treatment: Localize the infection by clipping away the hair. Apply warm soaks for 15 minutes three times a day. Saline soaks (1 teaspoon, 10 g, of table salt to 1 quart, 1 l, of water), or Epsom soaks (1⁄4 cup, 33 g, of Epsom salts to 1 quart, 1 l of water) are useful. Splinters and foreign bodies beneath the skin are a continuing source of infection and must be removed.
Pimples, pustules, furuncles, boils, and abscesses that do not drain spontaneously may need to be lanced by your veterinarian. If there is a sizeable cavity, your veterinarian may ask you to flush it once or twice a day using a dilute antiseptic surgical solution such as chlorhexidine until healing is complete. Your veterinarian may place a drain in a large abscess to help speed healing.
Oral and injectable antibiotics may be prescribed to treat wound infections, cellulitis, abscess, and other pyodermas.