ALLERGIES

Allergies or hypersensitivities are a common problem in dogs and can be an extremely frustrating problem for both you and your pet. Allergies occur as a result of an extreme reaction by the immune system to a foreign substance (allergen) which can cause a variety of symptoms. The most common symptom is pruritis - or itchiness of the skin - which causes the dog to scratch and chew, which in turn can lead to hair loss, open sores and secondary skin infections. Other symptoms include diarrhoea which is usually caused by sensitivity to certain food types, or coughing and sneezing if they are sensitive to something that is inhaled, for example pollen (yes, dogs suffer from hay fever too!).

One of the most frustrating parts of owning a dog with allergies is trying to identify the cause. Anything in the environment can potentially cause a reaction in your dog so you should try and think back to when the symptoms first occurred. Had your dog been anywhere different on his or her walk around that time? Had you used any different cleaning materials in the house where the dog lies or goes i.e. carpet shampoo or new washing powder on the dog’s bedding? Had you changed the brand of food that your dog is fed, or fed him/her something different as a treat? Or have these symptoms occurred before at a similar time of year? Allergens come in almost any form so it is worth mentioning any ideas to your vet however unlikely or insignificant they may seem.  

One of the most common causes of skin allergy in dogs is Flea Allergy Dermatitis (FAD). Any flea presence will cause a certain degree of irritation to a dog. However, some dogs are so extremely sensitive to the flea saliva, which is injected into the dog when the flea is feeding, that the presence of a single flea can cause such intense pruritis that the dog will repeatedly chew and scratch at its skin causing secondary damage which often leads to infection. As with all allergies, treatment for this is to remove the cause which in this case can be quickly and easily achieved with the use of a spot on flea treatment available from your veterinary surgeon. Depending on the extent of secondary damage caused to the skin by your dog scratching and chewing, he or she may also require a course of antibiotics and possibly some steroids to relieve the itchiness. It is also important to ensure that you treat your house for fleas as 95% of the flea’s life cycle is spent in the carpets and furnishings of your home. A good quality environmental flea treatment will be available from your veterinary surgeon. Finally, it is essential that you use preventative flea treatments regularly on all cats and dogs in the household all year round to minimise the risk of future exposure to the allergen.  

Food allergies arise due to a reaction to a particular food product such as gluten, dairy or beef, for example. Symptoms include pruritis and often diarrhoea. This type of allergy is, in theory, one of the easiest to investigate. However, it requires true dedication and a lot of will power by the owner. Your vet will prescribe or recommend a specialised diet for your dog which excludes the more common food allergens. This is where your will power comes in! It is essential that your pet is fed this and only this food for at least 6 weeks, no treats, no titbits and only water to drink. If your dog’s condition has improved at the end of this time then you can begin to introduce other food types one at a time for a week each time and see which ones cause a relapse, thereby identifying the food type or types that your dog is sensitive to. It is important to note that one dog can have allergies to more than one food type so do not stop testing foods after you have found one that causes a reaction.  

Other, less easily identifiable allergies include contact allergies (caused by allergens in the environment that your dog may come into contact with at any time) and inhalant allergies (including dust, pollens and moulds). Contact allergies often cause irritation around the feet (if the allergen is on the ground where the dog walks), or along the dogs tummy, elbows and hocks (if it is something where they lie). Inhalant allergies tend to cause a more generalised pruritis, causing your dog to chew and scratch all over its body, around his or her face and feet, and in the groin. They may also cause respiratory signs (e.g. wheezing, sneezing) and watery eyes.  

If you are unable to identify the cause yourself, your veterinary surgeon may recommend intra-dermal allergy testing which involves the injection of a small amount of commonly known allergens into the skin in order to try and provoke a reaction and thereby identify any which your dog is sensitive to. This often requires referral to a veterinary dermatologist. Once a cause has been identified then avoidance of further exposure is the best option. However, if this is not possible then other options such as immunotherapy vaccines (personalised vaccinations against the specific allergen your dog is sensitive to) or symptomatic treatment (simply treating whatever symptoms your dog is displaying as and when they occur which may include antihistamines, antibiotics or steroids among others) can be discussed with your vet.

Copyright ©2009 Ben Cornish. Site designed by JNF