Atopic Dermatitis

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ATOPIC DERMATITIS

 

Atopic dermatitis (AD) is an increasingly common and often misunderstood problem and as such one I thought might be worth a closer look. This is based on the fact that there have been a number of posts recently with eczema type symptoms being the central theme, in the majority of post the dogs would seem to be suffering AD type problems, indeed some had already had a veterinary diagnosis made.

 

AD is an allergic reaction; basically the body has an exaggerated immune response due to an imbalance in the system which leads it to respond excessively to the allergen. It is thought that around 10% of dogs suffer with this and some breeds more predisposed than others. There is a genetic link in around 50% of cases with some breeds like the West Highland white terrier being very predisposed, some bull breeds are also beginning to show an increasing prevalence. So the first bad news, with such a high genetic link it would I would be hard to justify any dog having a diagnosis of AD being used for breeding.

 

The disease first presents as just itching but this is usually followed by inflammation, and as the dog continues to scratch it begins to cause self harm. This can become infected with bacteria or fungal spores and a negative cycle begins. Commonly the ears and muzzle are sites of first presentation though occasionally other area such as armpits/forelegs or groin can start, these areas often start to show symptoms as the disease progresses. Most dog present from 6 months to 3 years although most are around a year old when the first trips to the vets are made

 

There has been work on causative allergens and this is one area that is often misunderstood with the common cry of everyone's favorite scapegoat gluten being blamed. Occasionally there is a food allergy that will cause the problem but in the majority of cases it is an environmental allergen that is the culprit with house dust mites being the commonest or and pollen for seasonal sufferers, fleas are now a less common factor. Now the second bad news, as the causative factor is usually environmental it can be difficult to avoid constant exposure, this means treatment is problematic with ongoing itching, skin damage and a poor long term prognosis.

 

This brings us to treatment, the international Force for Canine AD recommends a multiple pronged approach to flare ups with steroid cream/ tablets, immunosuppressant drugs, like ciclosporins, non irritant baths and antibiotics/antifungals. There is evidence that the addition of essential fatty acids to the diet can improve symptoms in the longer term and some dogs are helped with antihistamines but this is very individual. With dogs that are allergic to house dust mites kenneling outside helps reduce symptoms and with pollen sufferers exercising on beaches or when pollen is low might help a little.

 

For those that have a dietary cause then a strict change of diet to something like Skinners duck and rice, or a home made diet with a new protein with rice or suchlike, should show improvement. Avoid adding in herbal supplements as this just muddies the water, the diet most be very strict with absolutely no additions for at least six weeks. That means no supplements other than the fatty acids, not treats, table scraps, meat or bones or anything at all, basically just the food out of the bag. The easiest sensible fatty acids are from the local farm/horse suppliers who will sell Cod liver oil by the litre for around £20 which is a lot more sensible than a pot of pills costing a fiver that has about 10mls of actual oil. A teaspoon a day on the food should be enough if it is going to help. The last option is allergy testing followed with allergen specific immunotherapy, giving increasing doses of the allergen to build up acceptance from the immune system. This can be expensive and difficult for dogs continually exposed to environmental allergens.

 

So in conclusion treatment should be led by a vet in the first instance as misdiagnosis are common.. Treatment can be time consuming and expensive, many dogs are put down due to AD, so a sensible approach needs to be taken, exclusion diets and reducing exposure to house dust mites and fleas are a good start. Wooden floors, clean dog beds or outside kenneling for part if not all of the day are easily implemented and often effective to the point of reducing the need for medication to a minimum. Lastly don't breed from AD dogs or from litter mates of affected animals as severity of symptoms may not indicate genetic predisposition.