Symptoms of a staphylococcus skin infection in dogs include mouth and skin abscesses, constant itching, and pus-filled lesions, according to petMD. Other signs of this bacterial infection are fever, pain and a decrease in appetite. Abscesses begin as surface wounds and can develop into deep infections within the skin tissue.
Although the staph bacterium invades the skin of dogs, it can affect the upper respiratory tract as well, details petMD. Dogs with compromised immune systems are more susceptible to catching a staph infection. Biological cell abnormalities may also increase a dog's chances of being infected with staph. Veterinarians conduct blood tests, urinalyses and skin biopsies to determine the presence of such infections.