Differences Between a Dog's Staph Infection and Ringworm

Ringworm and staph infection can cause similar-looking clinical signs on a dog's skin, but they're caused by entirely different organisms. If you suspect your dog has any kind of fungal or bacterial infection, seek the advice of your veterinarian prior to beginning any type of treatment regimen. Your vet will most likely want to confirm the cause of the infection via laboratory tests prior to making recommendations for treatment.

Staphylococcus bacteria live in the environment, and on the skin and in the mucous membranes of humans and animals including dogs. While staph does not normally create problems for healthy dogs, it can infect malnourished dogs, stressed dogs, dogs under than one year of age and those with compromised immune systems. Clinical signs of a dog's staph infection include skin sores, lesions or scabs, pimples, hair loss, redness of skin and excessive dander. Many dogs with staph infections will itch. In some cases, staph can cause infection of the eyes, ears and respiratory system.

Once your veterinarian has confirmed the presence of Staphylococcus bacteria through a skin culture, she will likely recommend your dog receive a full course of antibiotics. As with humans, some strains of staph infection resist typical antibiotic treatment. If your dog does not show signs of improvement within a week or so, your vet may need to prescribe an alternative medication.

Ringworm in dogs causes clinical signs visible on the skin and coat, similar to those of a staph infection. Unlike staph, which is caused by bacteria, ringworm originates from a fungal infection. Visible signs of ringworm include broken coat hairs, reddened or discolored skin, patches of hair loss and, possibly, skin lesions. The hallmark sign of ringworm is hair loss in circular patches, primarily on the head, ears and paws -- although with a serious infection, a majority of a dog's body may be involved. As with staph infections, dogs become more vulnerable to ringworm infection when they are malnourished, have weakened immune systems or are very young.

Your veterinarian may employ several diagnostic methods to confirm the presence of ringworm, including a skin culture or examination of skin and hair cells using an ultraviolet light called a Wood's lamp. Once diagnosed, your vet will likely recommend an anti-fungal shampoo, dip or other topical treatment. Oral anti-fungal medications may be prescribed, especially for more serious cases of infection. Once treatment begins, dogs begin to show improvement in one to three weeks.

Staph and ringworm transmit easily to other animals and humans. If you have any other pets in your home, keep your infected pet quarantined. Sterilize bedding, toys, food bowls and any other items your infected dog has had contact with using a solution of 1 part bleach to 10 parts water. Use rubber gloves when bathing or handling your dog, and wash your hands thoroughly after touching him.