Impetigo and acne are mild surface skin infections that occur in puppies under 1 year of age. Impetigo presents with pus-filled blisters on the hairless parts of the abdomen and the groin. The blisters rupture, leaving thin brown crusts. Puppies housed in unsanitary quarters are most likely to be infected.
Acne occurs in puppies 3 months of age and older. It can be identified by purplish red pustules and blackheads that come to a head and drain pus. These lesions are found on the chin and lower lip, and occasionally in the genital area, perineum, and groin. Blockage of hair follicles by skin scales and sebum is a predisposing cause. Acne is more common among Doberman Pinschers, Golden Retrievers, Boxers, Great Danes, and Bulldogs, but can occur in any puppy.
Treatment: Topical therapy for impetigo and mild acne involves bathing the puppy with a benzoyl peroxide shampoo (OxyDex or Pyoben) twice a week for two to three weeks. Correct any predisposing causes, such as unsanitary puppy quarters.
Acne is often a deep-seated skin infection and may not respond to topical therapy alone. Your veterinarian may add a course of oral antibiotics that are effective against Staphylococcus. Acne usually resolves spontaneously at sexual maturity.