Treatment of Atopic Dermatitis in dogs and cats

What is atopic dermatitis?

Atopic dermatitis is an allergic skin disease affecting both dogs and cats. The exact cause or development of atopic dermatitis is not fully understood but it is currently thought that affected animals are genetically predisposed and as a result, they have an exaggerated immune response and defective skin barrier. A poor skin barrier allows easy penetration of bacteria/yeast (naturally residing on the skin) and environmental allergens (such as pollens and mites) and consequently, these “foreign invaders” exacerbate the detrimental cycle of skin inflammation and feeling itchy. Certain breeds are more likely to develop atopic dermatitis than others such as, in dogs, West Highland White Terriers, French Bulldogs and Labradors.

How can atopic dermatitis be treated in dogs and cats?

As previously mentioned, atopic dogs and cats have inflamed and itchy skin; to protect the skin and make affected animals feel less itchy, anti-itch treatment should be started.

In general, there are six different anti-itch treatment options available, all with various pros and cons. There is not one option that suits all dogs and cats, so it is the responsibility of the dermatologist to choose the most suitable. Examples of factors influencing the decision include:

• If itching and/or the affected skin (including the ears) is localised or widespread
• How quickly it takes for the treatment to have an effect
• What treatment has been tried before and what has worked well
• How the skin looks and if a secondary infection is present
• Route of administration
• Cost and owner preference.

Medication: Topical steroid – Cortavance*

What is it and how does it work?

An anti-inflammatory that inhibits the process of inflammation in the skin only, i.e. minimal systemic effects

How is it given?

It’s a solution that is either:

• Sprayed onto the skin
• Applied into the ear

How long does it take to have effect?

Effect can be quite rapid with obvious improvement after 1-2 weeks.

What is the cost?

1 bottle costs approximately £70 and once opened can be used for 6 months.

Are there any side effects?

Short-term: none reported

Long-term: thinning of the skin, alopecia, ulceration

* Licensed for use on the skin of the body only

Medication: Cytopoint (licensed for dogs only)

What is it and how does it work?

Synthetic antibody that neutralises a specific cell type involved in allergy.

How is it given?

Injections given every 4 weeks to start with then potentially every 5 – 6 weeks.

How long does it take to have effect?

Effect can be rapid with improvement within 24 hours.

What is the cost?

Treatment is expensive. For example, an injection for a medium-sized dog for a month would cost approximately £100.

Are there any side effects?

None reported so far. (New medication)

Medication: Prednisolone/ methylprednisolone/ dexamethasone

What is it and how does it work?

Anti-inflammatory that inhibits the process of inflammation.

How is it given?

Tablets or liquid given daily to start with, then tapered.

How long does it take to have effect?

Effect can be rapid with improvement within 24 hours.

What is the cost?

Inexpensive, for example a month’s course of tablets for a medium-sized dog would cost approximately £20.

Are there any side effects?

Short-term: Increased drinking and urination, increased appetite and weight gain.

Long-term: Muscle wastage, urinary tract infections, induced hormone disease (Cushing’s)

Medication: Atopica/ Cyclavance/ Sporimmune

What is it and how does it work?

Another anti-inflammatory that inhibits the different cell types involved in allergy.

How is it given?

Capsules or liquid given daily to start with, then tapered.

How long does it take to have effect?

Speed of action is slow and can take 4 – 6 weeks.

What is the cost?

Most expensive, for example a month’s course of capsules for a medium-sized dog would cost approximately £275.

Are there any side effects?

Short-term: Vomiting and diarrhoea can occur.

Long-term: Thickening of the gum, increased hair growth, risk of secondary skin infections

Medication: Apoquel (licensed for dogs only)

What is it and how does it work?

Blocks the neural pathway that causes the sensation of itch.

How is it given?

Tablets given twice daily for 2 weeks, then once daily.

How long does it take to have effect?

Effect can be rapid with improvement within 24 hours.

What is the cost?

Expensive, for example a month’s course of capsules for a medium-sized dog would cost approximately £85.

Are there any side effects?

Short and Long-term: Urinary tract infections, cystitis, vomiting, diarrhoea, skin abnormalities including masses.

Medication: Allergen specific immunotherapy

What is it and how does it work?

It’s a solution containing a tiny amount of selected allergens. The intention of this treatment is to desensitise the immune system to the allergens in the solution so that when they are encountered in day-to-day life, no allergic reaction results.

How is it given?

Injection given every few weeks to start with, then every month.

How long does it take to have effect?

Speed of action is very slow and it can take 9 – 12 months to see an improvement.

What is the cost?

Initially fxpensive, for example a vial for one year could cost approximately £250-£300.

Are there any side effects?

Side effects are very rare but a few side effects are reported to transiently occur after the injection is given, including itchiness, sleepiness, vomiting/ diarrhoea.