There are a variety of conditions that can make a dog itch or sneeze, including endocrine, autoimmune, infectious, and parasitic skin diseases. Therefore, some detective work is necessary to identify the right cause.
If allergies are thought to be the cause, the first thing a veterinarian will usually ask is if the dog is on a flea-control product. Flea allergies are the most common type of allergies and the easiest to control. Dog owners have many options available from high-street and online pet stores.
Once flea allergies are ruled out, and if the itch is non-seasonal, food allergies are the next thing to be checked. Food allergies are not seasonal, whereas most atopic allergies begin as a seasonal problem.
Dogs which develop atopic allergies usually show symptoms between 1 and 5 years of age, but food allergies can be a problem at any time. They are high up on the list of suspected causes when a dog first gets itchy skin at an age less than 6 months, or over 5 years.
When testing for food allergies, the dog is put on what is referred to as an “elimination diet” for around 10 weeks. This means the dog is fed food that consists of a protein and carbohydrate that the dog has not eaten before, such as venison, duck, and potatoes.
Veterinarians offer these special foods, and some may be found in pet stores. Another option is to feed the dog a homemade diet of foods based on recommendations from the veterinarian.
If the dog’s itching subsides, the allergen is clearly being caused by one of the foods that make up its regular diet. To confirm this, the dog owner can reintroduce the old diet to see if the symptoms return.
To check for atopic and contact allergies, veterinary dermatologists use an intradermal allergy test (also known as a skin reaction test). The dog is mildly sedated, a postcard-sized area on the side of it is shaved, and small amounts of potential allergens are injected into the skin. Should the dog be allergic to a particular substance, the skin will become slightly inflamed, showing that the cause of the allergy has been found.