Scabs, blisters, and purulent crusts can develop on the skin of newborn puppies 4 to 10 days of age. These sores sometimes contain pus. They usually appear on the abdomen and are caused by poor sanitation in the whelping box.
Treatment: Keep the nest clean of food, stools, and urine. Check for any signs of external parasites, such as fleas or Cheyletiella mites, in the bedding. Cleanse scabs with a dilute solution (1:10) of hydrogen peroxide or wash with a dilute antiseptic solution such as Betadine or chlorhexidine. Then apply an antibiotic ointment such as triple antibiotic or neomycin.