Skin Infections - How Do They Occur, What Are The Signs?
Skin can become infected in many ways.
Dermatitis, or inflammation of the skin, is caused by agents such as irritants, allergens, and bacterial, viral, parasitic and fungal infections.
Parasites can cause the skin to become infected – these include red mange or demodicosis, sarcoptic mange, the migration of parasite larvae, and flea, tick and lice infestation.
There are numerous degenerative diseases of the skin and hair coat that may occur. These include various forms of alopecia and excessive shedding.
Skin diseases can arise from abnormal immune reactions. These form areas of persistent, sterile inflammation. Examples include injection reactions, eosinophilic dermatopathies, puppy strangles, sebaceous adenitis and sterile pyogranulomas.
Immune-mediated skin diseases may develop – for example, atopy (inhalant allergy), contact allergies, discoid lupus, systemic lupus erythematosus, vasculitis and the pemphigus complex.
Hormonal (endocrine diseases) can cause skin and hair coat changes. Examples of these are hypothyroidism, hyperadrenocorticism (Cushing’s disease) and sex hormone abnormalities.
Nutritional deficiencies, such as with protein, fatty acid, vitamin A and zinc, can often cause skin and hair problems.
Numerous forms of skin cancer can also occur (both benign and malignant).
Some dogs develop lesions as a result of constant scratching, biting and licking of the skin. These lesions can then become infected.
Injury from foreign objects, internal infections and autoimmune deficiencies can also cause the skin to become infected.
Signs that an infection is present include:
Skin becoming inflamed and/or swollen
Possible lumps on the skin
Sores, scabs or weeping areas
Hot spots, hair loss and crusty lesions
The skin may be warm to the touch
Persistent scratching, biting and licking of the skin, and an unusual amount of hair loss can also be a sign.