Clinically known as atopy, inhalant allergy is a hypersensitivity to environmental allergens manifested through irritation of the skin and ears. Atopy occurs in 10 to 15 percent of the dog population and tends first to occur when the canine is between one to two years old. Feline atopy can occur at any age. It is not uncommon for animals to have atopy in conjunction with other allergies such as food hypersensitivity and flea allergy dermatitis.
Cushing's disease results from excessive production of cortisol, a hormone normally produced by the adrenal glands. This excessive cortisol production can result from abnormalities in the pituitary gland that cause excessive hormone secretion by the adrenal glands, by tumors within the adrenal glands themselves, or by a combination of these factors.
Lesions occur most commonly on the trunk, the legs, the digits (toe), the scrotum, the lips, the anus, and the nose. The lesions are typically ulcerated or cauliflower-like in appearance, bleed easily and are typically solitary.