Living with an itchy dog is no fun – but being an itchy dog must be worse! Atopy affects around 1 in 10 dogs to some degree. In dogs the condition can cause a variety of signs: skin disease, runny nose, itchy eyes and (very rarely) asthma. If your dog persists in licking its feet or has recurrent ear or skin infections, it may have atopy. As a general rule itchy skins do not resolve without treatment; so if your dog is scratching an early visit to your vet is advisable. Itchiness is not normal, nor is it a habit.
What is atopy?
Atopy or ‘atopic skin disease’ is a genetically-predisposed tendency to develop an allergy to environmental allergens. The most common allergens are house dust mites, storage mites, pollens (grass, weed and tree), moulds, skin dander and less commonly dietary proteins. In allergic animals, the immune system over-reacts to contact with these foreign substances causing inflammation that leads to itchiness. Dogs display this irritation by rubbing, licking, chewing, scratching and biting themselves or scooting along on their backside.
My dog did not have atopy as a puppy why has it suddenly started?
Dogs with atopy are born with the potential tendency to develop significant allergic responses. As the dog comes into contact with more and more allergens in its normal life, these allergies start to develop. Most dogs with atopy start to show signs between 1 and 3 years of age. It would be very unusual for a puppy younger than 6 months to develop signs of atopy. If your puppy shows signs of itchiness before this age it is most likely that there is another reason for it. Some breeds of dog are far more likely to develop atopy than others and if there is a history of atopy in your dog’s family then they are more at risk of developing signs.
How do I know if my dog has atopy?
Your dog may have atopy if it suffers with recurrent ear or skin infections that clear up with treatment but then come back some time after when treatment stops. The body sites typically affected in dogs with atopic dermatitis are:
the face and ears
between the pads of the feet
in the armpits or groin area.
If your dog is forever licking at or rubbing one or more of these sites, even if you cannot see any skin lesions, make an appointment to see your vet. Typically dogs with atopy start off with seasonal disease. However, in subsequent years the skin disease will often start earlier and last longer. If you can answer yes to the following questions there is a high chance that your dog may have atopy.
Was your dog younger than 3 years old when it first showed signs?
Is the dog mostly kept indoors?
Was the itchiness present before you noticed skin lesions?
Does your dog have reddened front paws and are the inner surface of the ear flaps affected?
Are the margins of your dog’s ear flaps unaffected?
How does my vet know that my dog has atopy?
Your vet should also begin to suspect that your dog has atopy based on a history of recurring skin or ear infections, particularly if these clear up over the winter and come back the following year. Atopic dogs with light-coloured coats often have brown, saliva-stained fur in sites where they lick constantly. If your vet thinks it is likely that your dog has an allergic skin condition they will want to do some other tests. But firstly your vet should ensure that regular, prescription, ectoparasite control has been used and they may prescribe treatment to clear up any secondary skin infections. If the symptoms are not seasonal, then your vet must recommend a strict, food elimination trial for several months. Feeding your dog a specific, truly hypoallergenic diet helps to rule out a food reaction as the cause of the itchiness. If your dog is still itchy after all this treatment, and the diet trial, then referral to a specialist dermatologist for intradermal skin testing should be offered. Under light sedation, an area of skin over the body wall is clipped and prepared. Tiny volumes of allergens are injected into the skin and your dermatologist will monitor the reaction to these allergens in the skin to decide which are likely to be causing itchiness. Depending on the intradermal test results it may be possible to treat the condition with allergen-specific immunotherapy.
Is there any treatment for atopy?
Yes. The main priority for treating atopic dermatitis is to reduce all the factors that may cause the skin to be inflammed. It is very distressing for a dog and owner when a dog is scratching all the time. The management options currently available are listed below and the combination that works for your dog needs to be tailored specifically for individual conditions:
It is often possible to reduce the dog’s overreaction to allergens by the use of allergen specific immunotherapy (desensitising vaccines). These injections must be given over a period of some months and in over two-thirds of dogs these help to reduce the severity of the allergy. If you are considering desensitisation you will have to be patient – improvement may not be seen for around 9 months after the course of injections starts. Following that monthly lifelong injections are required, and it is rare for the condition to be controlled without the need for other managemental or medical interventions.
It will be important to take particular care in preventing parastic infection. Atopic dogs are prone to sarcoptic mange infection and also more likely to become allergic to fleas.
Complete diets, with higher levels of essential fatty acids, may assist with control of skin conditions. Of course it is important also to avoid any dietary allergens that were implicated during the food trial.
Regular cleansing of the coat, ears and paws to mechanically clear surface allergens, assist with natural skin cell shedding and improved skin barrier function will be beneficial.
Common recurrent yeast and bacterial infections must be controlled – ideally with regular medicated washes and ear cleaners.
Anti-inflammatory medications, both systemic and topical (sprays, gels, shampoos and rinses), should be employed when necessary on top of all the above strategies.
Other drug therapies may also be needed – steroids are cheap, but potentially have many side effects. Cyclosporin A has few significant side effects though is comparatively expensive. Antihistamines are usually cheap, with few side effects, but are invariably ineffective.
Will my dog get better?
It is very rare for dogs with atopy to be cured or grow out of the problem. In fact they generally have more severe episodes each year. However, in most dogs the condition can be controlled by careful, diligent management.
What else can I do to help my dog?
If it has been possible to identify the specific allergens involved in your dog’s case, by intradermal and/or serological testing, then it may be possible to avoid things that are likely to cause reactions in your dog. For example, if your dog is allergic to pollens it may help to keep them inside when the pollen count is high or when you are mowing the lawn. Elimination of house dust mites is difficult but regular hot washing of the bedding plus annual environmental spraying can help kill mites. Dogs with house dust mite allergy may benefit from preventing access to bedrooms, soft furnishings and carpets. If you have any concerns about our dog contact your own vet for further advice.