Veterinary Dermatology & Allergy

Common endocrinopathies in the dog include hypothyroidism and Cushing’s disease (hyperadrenocorticism). These two conditions can cause loss of hair, brittle hair, changes in hair color, and skin infections. Seasonal flank alopecia is another disease that also may involve hormones.

Cats, also can have skin and hair coat changes due to endocrine disorders. Cats may have similar changes to the hair and coat as dogs from hyperthyroidism and thymomas. Blood tests may be utilized to diagnose these disorders. In certain cases a skin biopsy may be needed.

These conditions are characterized by dysregulation of the immune system that cause the body to attack itself. In some cases a trigger (infection, virus, drug) may cause the dysregulation – your dermatologist will carefully look over your pet’s history to identify this trigger.

For most of these conditions a skin biopsy with submission to a dermatohistopathologist is necessary for diagnosis. Most pets with these conditions can live long and healthy lives, but most will require life-long medical management.

Common immune mediated conditions are listed below:

• Pemphigus Foliaceous
• Discoid Lupus Erythematosus
• Symmetrical Lupoid Onychodystrophy
• Hepatocutaneous Syndrome
• Erythema Multiforme
• Toxic Epidermal Necrolysis

Cutaneous lymphoma (mycosis fungoides) causes generalized red, irritated, and itchy skin in older dogs. Often this form of skin cancer is confused with allergies. Performing skin cytology combined with your pet’s history and examination can raise our suspicion of skin cancer. Definitive diagnosis requires a skin biopsy.

Most skin infections, especially those caused by bacteria and yeast, are secondary to another disease process. The most common underlying cause of bacteria and yeast infections in dogs and cats are allergies. Endocrinopathies (disease of an endocrine gland) can also cause skin infections. Clinical signs of skin infections include scaling (flaky skin), hair loss, and itch (scratching, biting, chewing). It is very important to treat the infections, as well as the underlying cause, so that the infection does not re-occur. In some cases, an infection may be primary, meaning there is no underlying cause.

Primary Infections

• Dermatophytosis (ringworm)
• Mycobacterium
• Systemic fungal diseases (cryptococcus)
• Parasitic diseases
• Demodicosis
• Sarcoptes
• Hookworm
• Cheyletiella

Diagnosis of most of these diseases is usually straightforward for a board certified dermatologist. The dermatologist may use a combination of skin cytology, skin scrapes, and fungal cultures. For deeper infections, such as mycobacterium, a skin biopsy may be necessary to perform histopathology and culture.

We are able to remove small masses and treat certain dermatological conditions with our C02 laser. This method of treatment has several advantages over conventional surgery.

• Most procedures can be done by numbing the skin prior to the procedure. Often sedation and general anesthesia can be avoided.
• Less pain – the CO2 laser seals the nerve endings and little to no pain is experienced.
• Minimal hemorrhage (bleeding) and tissue destruction. The laser is a precise tool giving the dermatologist excellent control on how much tissue will be removed. This also limits post-operative swelling and inflammation.
• If a patient has multiple masses/tumors, conventional surgery may be too time consuming to be performed.

1. Removal of small masses: examples include sebaceous adenomas (warts), skin tags and papilloma’s.

2. Removal of cysts.

3. Removal of hemangiomas – small red areas caused by UV light. These tumor types can turn malignant.

4. Removal of tumors in difficult locations such as on the ears and tail.