Allergic skin disease. 2 Elimination diets

Of all dogs with allergies only about 7% have a primary dietary allergy. The chances of your pet’s allergies being food based increase if signs start before 6 months of age. Most commonly dogs are allergic to the protein source in the food. In Australia beef is the most common allergen, thought this changes depending on what foods your pet has been exposed to. Dairy products are also commonly implicated.

It is worth remembering that the composition of many foods changes between batches, so even if you don’t change brands of dog food, the protein source can vary. This is not true of super premium food such as Eukanuba, Hills science diet, and Advance.

Dietary challenge as part of the diagnostic process for allergic skin disease is important for the following reasons:

• If your pet does have a primary dietary allergy you can aeffectively cure their disease by modifying their food
• Food proteins may be one of the allergens that’s sends a dog over their threshold ( see diagram 1 in Allergic skin disease. 1 Causes & diagnosis)
• There are no reliable tests for food allergy, therefore if we are going to do skin or blood testing for allergens then we must rule out diet as a possible cause first.

What food do I use for a dietary challenge?

You can use either a home made diet or a commercial low allergy food, such as Hills Science diet Z/D ultra. There are pros and cons of both forms. Some veterinary dermatologists argue that homemade diets are superior, however as they are harder to make and use compliance can be an issue (see notes below).

For homemade diets you need to find a protein source that your pet has not been exposed to previously. By definition these tend to be hard to find, and/or expensive (otherwise they would be found in dog food).

Useful meat sources can be:

• Rabbit
• Goat
• Venison
• White fish ( you need to stick with the same type of fish through out the trial)

Carbohydrate sources can be:

• Sweet potato
• Tapioca

So for example you may choose venison & sweet potato for your trial.

There are many other options, and if you wish to use a home made diet we can discuss what will be best for your pet.

It is important to source meat from a reputable source (usually for human consumption) as meats cut on the same boards as beef will be contaminated and may negate the benefits of your trial.

Consistency is the key

The trial will run for 5-8 weeks. ANY break in the diet in that time and you need to start again. If for example you have a BBQ, and your dog steals a sausage, then you must start the trial again from that day, even if you are a month in to the trial.

Don’t use flavour tabs or chews for parasite control or other treatments during the trial. If you use flavoured heartworm preventions for example, use another form during the trial period. Topicals that you apply to the back of the neck such as advocate or revolution can be useful for this purpose.

Provocative challenge

If your pet seems to improve on the diet, after the 5-8 weeks we will usually do a provocative challenge. This means we put them back on their original diet & see if the skin gets bad again. This rules out the improvement being pure coincidence.

If all the evidence points to a dietary allergy, then we can organise a long term, and balanced diet for your pet.