Cheilitis usually results from an infection inside the mouth that extends to involve the lips. In hunting dogs, chapped lips can be caused by contact with weeds and brush. Dogs with canine atopy may irritate their lips by constantly rubbing and pawing the face.
Cheilitis can be recognized by the serum crusts that form at the junction of the haired and smooth parts of the lips. As the crusts peel off, the skin becomes raw and denuded and is sensitive to touch. Involvement of the hair follicles produces a localized folliculitis.
Treatment: Clean the lips daily using benzoyl peroxide shampoo (OxyDex or Pyoben), or hydrogen peroxide diluted 1:5 with water. Then apply an antibiotic-steroid cream such as Neocort. As the infection subsides, apply petroleum jelly or aloe to keep the lips soft and pliable. Chapstick may also be used. Periodontal disease or canine atopy, if present, should be treated to prevent recurrence.