Recurring skin infections in dogs usually happen when your dog has an underlying problem. These problems might include skin allergies, autoimmune diseases, or hormonal imbalances. Normally, there are several bacteria living on your dog's skin - these are commensal bacteria. These bacteria can multiply to unsafe levels, where they may take over breaks in the skin. A dog might also repeatedly get skin infections if their living quarters are unhygienic. Be sure to wash your dog's bed often, groom them well, and clean up their feces whenever possible. Many dogs suffer from bacterial infections when laying in a wet bed contaminated with feces.