Infectious Skin Disease

Infectious skin disease in dogs and cats can be caused by bacterial, fungal, viral, and protozoal diseases. Some of the most common diseases are Staphylococcal bacterial infections and/or Malassezia (yeast) dermatitis in dogs and dermatophytosis (ringworm) in cats.

A large part of the veterinary dermatologist’s job is controlling the secondary infection that results from inflammation in the skin and from disruption of the barrier function of the skin. The secondary infections contribute more inflammation and pruritus thus perpetuating the itch/scratch cycle. The Staph and yeast infections do not seem to be contagious to other pets or human beings. If skin infections persist, your pet should be re-examined.

Bacteria in the Genus Staphylococcus

Bacteria in the genus Staphylococcus are found normally on the skin of both humans and pets. For the most part, different species of staph bacteria inhabit the skin of humans and pets. The staph bacteria over grow as a result of inflammation in the skin from the underlying allergy and in response to self trauma as a result of pruritus from the allergy. This infectious skin disease is referred to as a secondary infection because without the underlying allergy and inflammation there would be no nidus for infection. The Staph bacteria are considered non contagious. Staph infections often involve the hair follicles. Common lesions include scaling, hair loss, papules, pustules, and/or epidermal collarettes. You may notice your pet has a strong odor.

Yeast in the Genus Malassezia

Yeast in the genus Malassezia are found normally on the skin of both humans and pets. For the most part, different species of yeast inhabit the skin of humans and pets. The yeast over grow as a result of inflammation in the skin from the underlying allergy and in response to self trauma as a result of pruritus from the allergy. This infectious skin disease is referred to as a secondary infection because without the underlying allergy and inflammation there would be no nidus for infection. The yeast are considered non contagious. Malassezia infections are superficial, common lesions include thickening of the skin, redness of the skin, and darkening of the skin. You may notice your pet has a strong odor. Malassezia dermatitis is considered one of the most itchy dermatologic conditions.