Symptoms of Dermatologic Diseases in Your Pet
Dermatologic (skin) conditions of companion animals are varied and can be complex. Symptoms of skin problems can include itching, hair loss, crusts or scale, rashes, and pustules or papules. Skin impression smears, scrapings, bacterial and fungal cultures, blood tests and biopsies may be indicated to diagnose the underlying problem(s). In general, dermatologic diseases can be divided into two general categories for purpose of simplification.
Common skin conditions associated with itching:
- Ectoparasites: fleas, ticks, ringworm, and mange. Fleas and ticks are not only a nuisance but carry diseases such as tapeworm, hemotropic mycoplasma, Lyme, Anaplasmosis, Ehrlichia and Rocky Mountain Spotted Fever. Additionally, some pets are allergic to flea bites and can have concurrent flea allergy dermatitis. Ringworm can cause single or multiple skin lesions with crusting and itching. Mange can be caused by two different kinds of mites – Sarcoptes or Demodex. Sarcoptic mange is contagious from one pet to another, while Demodectic mange is not. Demodex mites live on healthy skin, but in immune-compromised patients may overgrow causing itching and crusts. Each of these ectoparasitic conditions requires its own particular treatment for resolution.
- Allergy: by far one of the more common dermatologic problems; allergies can be environmental/inhalant (Atopy) or food-based. Atopy represents about 80% of all pet allergy cases. Symptoms of allergic skin problems can include chewing at the feet, scratching at the ears or rubbing eyes, hair loss, perianal itching, and secondary skin infections and ear infections. Managing allergies is a complex process and can require multiple forms of treatment for the life of the pet.
- Bacterial or yeast skin infections: most commonly, bacterial or yeast skin infections are not a primary problem, but rather secondary to other skin conditions such as allergies, and mange.
Common skin conditions not associated with itching:
- Endocrine (hormonal) diseases: Cushing’s Disease (hypercortisolism) and Hypothyroidism are the most common endocrine diseases causing skin problems. Patients with Cushing’s or Hypothyroidism may have thinning hair and dull hair coat. Often they can be prone to secondary yeast or bacterial skin infections, which then can create itchy skin. Additionally, Cushing’s disease can cause a skin condition known as calcinosis cutis, which leads to calcium deposits forming in the skin, giving it a crunchy feel.
- Sex-hormone alopecia, Seasonal Flank Alopecia, and Color-Dilution Alopecia: these conditions all result in symmetric hair loss or thinning hair, and are considered to be breed-related or genetic conditions.
- Auto-immune skin disorders: Pemphigus, Discoid Lupus, and Sterile Pyogranulomatous Dermatitis are all skin disorders causing variable skin lesions that are not itchy. These diseases typically require multi-modal treatment including oral steroid therapy.