The word “pyoderma” is Latin for pus in the skin. It is the medical term used to describe a skin infection. The most common type of skin infection is caused by Staphyloccus (“staph”) bacteria, usually Staphylococcus intermedius. Hence the name “staph pyoderma.”
The infection usually looks like round areas of hair loss, redness and scaling. Sometimes pimple will be seen, but often the skin looks blotchy and red and the hair coat “moth eaten.” There are usually flakes or crusts of dead skin cells around the margins of the reddened areas. The abdomen and groin are the most frequently infected, although staph pyoderma can occur almost anywhere on the body.
A related type of skin infection is acute, moist, superficial dermatitis, commonly known as a “hot spot.” Hot spots are very localized areas of skin infection. They appear as a round, moist, raw lesion anywhere from an inch to many inches in diameter. These arise when a dog licks or scratches any area excessively, and they often start with an insect sting or minor injury. Hair may be
gummed over the area, making it hard to see, and it may be very painful to the touch.
Our world is literally full of bacteria – they are on our skin, floating in the air and likely to be resting on anything we touch. Our skin, and the skin of dogs and cats, usually acts as a barrier to keep unwanted bacteria outside and not inside our bodies. If the skin is irritated or damaged by something else, the bacteria that live on the skin grow, multiply and set up housekeeping on and beneath the surface of the skin. Pyoderma is considered to be a secondary disease – a disease which arises because of some other problem which weakens the integrity of the skin or of the immune system.
Common problems which let these bacterial infections get started are:
- Parasites such as fleas, ticks, mites, or lice
- Hormonal diseases
- Biting insects such as gnats, mosquitoes, or flies
- Excessive moisture from swimming, wet bedding, or damp conditions
- Excessive skin folds, such as on the face, the base of the tail, leg creases or vulvar folds, which trap moisture and harbor bacteria
- A juvenile immune system – puppies are especially prone to these infections
- Genetic problems – some breeds seem predisposed to have poorly functioning immune systems
Sometimes we know what the initiating cause of the infection is, either because we find a problem such as fleas on our physical exam or because the owner can tell us something the dog was doing before the infection started, such as swimming, that precipitated it. Many times we never find out the cause of the infection or find it only after treatment has already been done. Because the skin reacts to a large number of diseases by getting red and itchy, and because there frequently are multiple skin problems going on at the same time, diagnosing and treating staph infection can be challenging.