Common causes of skin infections in dogs, cats

Published 10:24 am Wednesday, September 21, 2016

By Jeff Castle, Clark County Veterinary Clinic

Pyoderma is the medical term used to describe bacterial skin infections in pets. Dermatitis and impetigo are also terms often used for this condition.

Pyoderma is one of the most common skin problems seen in pets. The infection may be a primary condition or it may be secondary to an underlying problem.

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Often, allergies or thyroid conditions are the primary condition leading to a secondary skin infection. It is not always enough to just treat the skin infection without addressing the underlying cause.

The most common symptoms of pyoderma are hair loss, dry skin, scabs and itching. Sometimes it is possible to actually see pustules, which are like little tiny pimples. More often than not, the pustules have already ruptured leaving the skin looking red, inflamed and flaky patches of skin. The lesions are easier to detect on the areas of the pet’s body that is not covered with as much hair such as their belly and their underside.

The big question from many pet’s owners is “How did my dog get a skin infection?” Most skin infections are caused by normal bacteria found on the skin. The skin’s surface becomes damaged due to excessive moisture, excessive scratching or some other irritant.

Pets often suffers from allergies that make their skin itch and subsequent scratching damages the skin allowing for bacteria to grow easier.

Staphylococcus is the most common bacteria found to cause pyoderma in dogs and cats. This bacterium is found normally on pet’s skin and in the environment. It is an opportunistic bacterium which means it only causes infection when the conditions are right for it to grow. Any abnormal or damaged skin becomes the right condition for the bacteria to cause infection.

Other factors that can damage the skin predisposing it to infection are fleas, ticks, or a hormonal imbalance such as a low thyroid.

Pyoderma can be diagnosed by your veterinarian examining your pet’s skin. The clinical signs and medical history are usually enough to determine the pet has a skin infection. Some diagnostic tests may be necessary to determine the primary underlying problem.

Skin scrapes may be performed to check for mange mites and fungal cultures are performed to rule out fungal infections such as “ringworm.” Blood tests may be recommended to determine if there is a hormonal problem such as thyroid or adrenal gland abnormality.

Allergies are one of the most common primary or underlying problems leading to skin infections. Other tests may be performed to determine your pet’s specific allergies.

Treatment of pyoderma consists mainly of using antibiotics to kill the bacteria causing the skin infection. In difficult cases where the infection does not seem to be responding, bacterial culture and sensitivity testing may be necessary to find the proper antibiotic for the particular bacteria. Additional methods of treatment include topical sprays or ointments. Pets tend to lick off the medication, though, which reduces the effectiveness.

Medicated shampoos containing peroxide and/or antibiotics can be very helpful fighting off a skin infection. It is a somewhat time-consuming process since most medicated baths requires leaving the shampoo lathered on the pet for 10 to 15 minutes each time you bathe them.

Severe infections require bathing the pet two or three times a week. Keeping your pet’s bedding clean and dry can also be very helpful in maintaining healthy skin.

Some chronic or very difficult cases of pyoderma may take several weeks of antibiotics and medicated baths to cure. Some pets that are extremely prone to skin infections may benefit from being on antibiotics routinely to help prevent bad infections.

Others may do well with routine medicated baths to prevent the pyoderma from recurring. In the most difficult cases, there is a medication similar to a vaccine called Staph lysate which may be administered by injection to desensitize the pet to the bacterium staphylococcus. These injections typically take at least a month to see the results.

If you have a pet that develops a skin condition, it could be pyoderma and you should contact your veterinarian as soon as possible to ensure your pet lives a long, healthy and happy life.