Dermatology

Litchfield Veterinary Hospital

289 Torrington Road
Litchfield, CT 06759

(860)567-1622

litchfieldvet.com

Dermatology

Many pets experience some type of dermatologic condition in their lifetime. Dermatology includes conditions affecting the skin, ear, nail or hair . Frequently a multi-modal approach is necessary to determine the cause of this type of condition.  Pets may experience a wide variety of symptoms from mild to severe, often leading to discomfort and affecting their quality of life. The skin has limited reaction, therefore many different conditions cause the same symptoms: redness, hair loss, and itching.  Symptoms may be treated, allowing for immediate relief, but unless the underlying cause is determined they often return.

Our doctors are experienced in diagnosing and treating dermatologic conditions, including complicated, chronic allergic disease. Dr. Carey has a strong interest in dermatology, she has experience using the newest therapies for allergic disease.  We now have therapies that can help patients with chronic allergic disease that have not responded to medication in the past.

If warranted we collaborate with board certified veterinary dermatologists to ensure your pet is receiving the best care. 

In addition to the information provided below, follow the links to learn more about the following:

Food Allergy in Dogs

Food Allergy- Diet Trials

Otitis Externa: Ear Infections

How to clean your pet's ears

Ringworm
 

Atopic Dermatitis

Atopic dermatitis is one of the most common skin diseases of dogs. However, the pathogenesis of atopic dermatitis still is poorly understood and there is no definative test for this disorder. Itchiness (purititis) and redness are considered the hallmark signs of atopic dermatitis. The age of onset is usually between 6 months and 3 years.

Atopic dermatitis is a hypersensitivity reaction to inhaled or absorbed enviromental allergens. The incidence of AD in the canine population is unknown but some studies estimate that it may be as high as 15%. A methodical approach to rule out the disease is necessary to make an accurate diagnosis. The diagnosis of atopic dermatitis remains a diagnosis of exclusion based upon history, clinical features, and the exclusion of other diseases with similar clinical features.

Paradoxically (and unfortunately), atopy seems to predispose dogs to flea allergy dermatitis and food allergy. Consequently, these two other diseases commonly coexist with atopic dermatitis. Similarily, bacterial pyoderma and Malassezia dermatitis both can mimic many of the clinical features of atopic dermatitis. Secondary pyoderma, bacterial overgrowth, and malassezia dermatitis also commonly occur as sequela to all allergic skin disease, thus increasing pruritis further. It is necessary to rule out food allergy before making a diagnosis of atopic dermatitis.

The development of atopic dermatitis is complex. In dogs, it is a genetically programmed and heritable disease. In cats, evidence suggests that the disease is heritable. Canine atopy can develop in any dog, but certain breeds are predisposed, such as terriers and retrievers.

The immunologic mechanisms involved in the development of atopic dermatitis are the focus of a great deal of study. For many years, it was presumed that allergic exposure and sensitization occured primarily through inhalation. Percutaneous allergen exposure is now thought to be an important additional part of the pathogenesis.

Clinical signs are typically seasonal at first, but may become year round over time. Usual areas of puritis include the face, ears, paws, extremities, and underside, but some dogs may have only localized signs. Secondary lesions, such as thickening and pigmentation of the skin appear with chronicity. Secondary bacterial and fungal infections are common.

The concept of triggering flare factors is crucial to the successful understanding and management of all allergic skin disease. The signs and severity of atopy will vary with antigen exposure, changes in environment, and seasons, if seasonal allergens are important to that dog.

Atopic dermatitis cannot be cured, and even the most successfully managed dogs will have an occasional flareup. Therapy for canine atopic dermatitis involves topical antipruritic therapies, parasiticides, antihistamines, fatty acids, glucocorticosteroids, allergen specific immunotherapy and cyclosporin. Successful long-term management requires substantial owner commitment.

Most studies indicate that 65% of dogs with atopic dermatitis will show significant improvement with immunotherapy. Long term therapy is needed and it may take 3 to 6 months or longer to see a reduction in signs. Allergy testing is safe for long term use and can be combined with other therapies.

Allergen Avoidance and the Prevention of Allergen Contact

1. Reduce outdoor exposure when pollens and molds are present in highest concentration.

2. If allergy to house dust mites allergens is confirmed, owners can utilize pillow case and mattress covers made of fabrics impenetrable to house dust mite allergens.

3. Dog beds- purchase washable beds (filled with polystyrene beads), wash the bedding every two weeks, replace beds every two years.

4. Avoidance of direct allergen contact- for example, limit exposure to grass (especially when grass is wet) if allergic to grass.

5. Atopic dogs have defective epidermal lipid barriers in their skin. It may be helpful to attempt to restore epidermal lipids by supplementing linoleic acid ( fatty acid supplements and using topical lipid supplements).

6. Weekly bathing helps to reduce pollen absorption. The ideal shampoo for the management of the allergic dog should be gentle, lipid barrier sparing, and prevent surface bacteria and yeast overgrowth.

If your pet experiences clinical signs of allergy for more than 6 months of the year we recommend allergy testing and using immunotherapy to help patients become less sensitive to allergens.