When an older cat develops a skin problem, the presenting complaint will point you to a group of possible diagnoses.

Need-to-know information about its mechanism of action, pharmacokinetics, and adverse effects.

In the simplest terms, allergic dermatitis refers to any inflammatory skin disease caused by any type of allergy. The unifying characteristic of these diseases is that they cause pruritus and subsequent inflammation. Depending on the etiology, the event may be short-lived or become a lifelong condition. Table 1 lists the reported allergic diseases of small animals. 1,2 These diseases are rarely uncomplicated and often involve secondary infections. Furthermore, more than one core allergic disease is often present concurrently. These factors can make diagnosis and management of allergic dermatitis cases challenging.

A 2-year-old intact male Siamese cat was presented to the University of Wisconsin School of Veterinary Medicine's Dermatology Service for evaluation of self-mutilation and psychogenic licking of the forelimbs and abdomen.

In a recent study, oral dextromethorphan hydrobromide was evaluated in 14 dogs with atopic dermatitis to determine whether the drug had any effect on repetitive behaviors associated with or suggestive of pruritus.

Ulcerative dermatosis of Shetland sheepdogs and rough collies is an inflammatory, erosive skin disorder of unknown etiology.

A 1-year-old 66-lb (30-kg) intact male Labrador retriever was presented to the University of Wisconsin School of Veterinary Medicine's Dermatology Service for evaluation of severe pruritus and skin eruptions on its trunk and distal extremities.

The internal medicine service at the Veterinary Medical Teaching Hospital at the University of Wisconsin School of Veterinary Medicine requested a consultation on a 7-year-old intact male Boston terrier in which pituitary-dependent hyperadrenocorticism had been diagnosed one month earlier.

A 14-year-old, 41-lb (18.5-kg), spayed female collie-mix presented for evaluation of intense pruritus and gradually worsening skin disease of more than one year's duration.