Muzzle folliculitis and furunculosis (chin acne, muzzle acne) is inflammation of the muzzle and lips in dogs. It occurs most often in young dogs of short-coated breeds. When dogs play or rub the chin area, hairs are broken and pushed beneath the skin surface. This leads to skin irritation, inflammation, and infection.
Dogs present with bumps and redness under the chin and on the lips. Your veterinarian may obtain skin samples from your dog and examine them under a microscope to look for a bacterial infection (pyoderma), yeast infection (Malassezia), or parasite (Demodex mite causing demodicosis. If the bacterial skin infection is severe and needs an antibiotic, your veterinarian may send a sample to a laboratory for a skin culture. Occasionally, your vet may also take samples to look for a fungal infection (ringworm).
Treatment may include topical or oral medications to treat skin infection and inflammation. Because some dogs rub the muzzle from itching your veterinarian may also discuss allergies and other causes of itching.