What can your dog be allergic to?
ENVIRONMENT
Around 40% of allergies are to environmental allergens, meaning something in the dog's environment (inside or outside the home).
This is a broad category, but the most common allergens are
- House dust mites
- Storage mites
- Pollen
- Mould Spores
Due to seasonal changes in the environment, we often see seasonal changes in the allergy and a variation at different times of year.
FLEA (or other insect) bites
Around 30% of allergies are to flea or insect bites. The bite causes an allergic reaction, which is itchy. If fleas are on your dog, or in their environment then they will continue to have a reaction and be itchy.
FOOD
Around 30% of allergies are to certain types of food, often to common protein and/or carbohydrate sources. In some dogs, this causes gastrointestinal problems too.
It is important to note the difference between a food intolerance (this just causes a localised problem to the gastrointestinal tract, which can cause vomiting and/or diarrhoea). Whereas a food allergy causes an overstimulation of the immune system, which is why it can cause itchy skin, alongside (in some dogs) gastrointestinal signs.
Further testing and treatment
Identify/treat any other causes of itching
One of the first things your Vet will want to do is treat/remove anything that could be making your dog itchy. For example, treating fleas, skin infections, ear infections, mites, lice etc...
Alleviation and response to medication
If your dog is itchy, it is important for us to reduce this to make your dog's life more comfortable. Depending on how severe the itch is, your Vet may recommend medication to control the itching. In some situations (for example for a short term allergy that only happens for a few weeks at a time), this may be appropriate to just control the itching as/when it happens. Sometimes we need to use treatment long term to alleviate skin allergies, but in this situation it is worth considering trying to find out more.
Is it a Food allergy?
Around 30% of skin allergies are to types of food, and so caused by the diet. In some situations, this can be deemed unlikely (for example, your dog is eating the same diet for a long time, but only gets itchy after certain walks or at certain times of year).
The only meaningful test to identify if your dog has a food allergy is by doing a FOOD EXCLUSION TRIAL. There are no useful other tests, so don't be fooled by online companies selling hair or saliva tests. These are notoriously unreliable.
A Food exclusion trial works by feeding your dog a new diet, which excludes anything they have eaten before for a minimum of 6 weeks. Full details on how to do this can be found on the link below.
Allergy testing
Once a food allergy has been ruled out, OR if it is deemed very unlikely, we can consider allergy testing for environmental allergens. This is where your Vet can test (by a blood test or intra-dermal skin test) to identify what environmental allergens your dog is allergic to. The value in doing this is to then attempt desensitisation (a form of treatment described below). Performing this otherwise is of little value.
As with food allergies, please do not waste your money on saliva or hair testing kits sold online. They have been shown repeatedly to be inaccurate and a waste of money, which is why Vets do not use them.
Desensitisation
This is the process of attempting to desensitise your dog to the allergens that are causing a problem. This only works for environmental allergens, so is worth considering after a food trial has confirmed your dog is NOT allergic to foods.
Allergy testing can be done by either a blood test or an intradermal skin test, to identify what your dog's immune system is over reacting to.
With this information an allergy specific immunotherapy can be developed for your dog. This will gradually be given to your dog (by injection) usually over the course of a year, starting with regular injections reducing to monthly. Over time, the aim of this is to desensitise your dog to the allergens, stopping them having an allergic reaction.
This is not a guaranteed fix and is successful in around 60% of dogs.
Managing skin health
Regardless of what is triggering your dog's allergy, it is crucial to aim for healthy skin. The skin is a very important defensive barrier, which is weakened in dogs with skin allergies. Encouraging healthy skin will help reduce the effects of an allergy.
- Skin health supplements - Omega 3 and 6 fatty acids have been proven to be very helpful. There are lots of skin supplements available, lots of which make quite impressive (un-proven) claims. Omega 3 and 6 has been shown to be helpful for dog's skin, so focus on these supplements.
- Skin moisturisers and shampoos help keep the skin clear of bacteria and yeast, and keep the skin barrier healthy. Different types of skin will require different shampoo's, so your Vet may be able to recommend the best ones for your dog specifically.
Long term medication and management
In certain cases, where an allergy is environmental, long term management will be needed. In many cases, the only effective way of doing this is with medication.
Depending on the severity of the allergy, this will often involve medication to control the itch and the dog's allergic response, and may only be needed intermittently/as needed or in some dogs is needed longer term.
Fortunately, in recent years some very beneficial advances in Veterinary Medicine allow for effective treatment options, which your Vet can discuss with you.
Avoidance
If possible, avoid or reduce your dogs exposure to allergens. Sometimes easier said than done, but household chemicals/diffusers/cleaners can be avoided. Certain walks at certain times of year may be worse for your dogs allergy, so it may be possible to adjust this. If your dog has a food allergy, avoidance of certain foods is key. If you dog has a flea allergy, avoidance of fleas is key. If your dog has a clear allergy to something in particular then it is worth exploring options to avoid this.