Initial Understandings for Elimination Diets

Understanding the Role of Diet in Allergic Skin Disease

Food elimination diet trials are a valuable diagnostic and management tool in dogs suffering from chronic skin or gastrointestinal conditions. These trials are often recommended when a dog presents with signs suggestive of food intolerance or allergic skin disease.

What is Allergic Skin Disease?

Allergic skin disease in dogs is multifactorial and may involve:

• External parasites (e.g. fleas, mites)
• Food hypersensitivity or intolerance , most commonly to: Beef Dairy Chicken Wheat Soy
• Environmental allergens , including: House dust mites Pollens Grasses Moulds

Eliminating external parasites is the first step in ruling out causes of pruritus. Once this is addressed, a food elimination trial becomes a critical next step, particularly for cases with recurring or non-seasonal symptoms.

When is a Food Elimination Diet Trial Indicated?

Diet trials should be considered in dogs showing any of the following signs:

• Chronic or recurrent itching , especially affecting paws, abdomen, armpits, or flanks
• Hair loss associated with licking, biting, or scratching
• Recurrent ear infections
• Chronic gastrointestinal disturbances , including gas, diarrhoea, or unexplained weight loss
• Facial swelling , urticaria (hives), or sudden skin eruptions
• Dry, crusty, or flaky skin
• Miliary dermatitis (pinpoint crusting)

These signs may overlap with both food-related and environmental causes. A strict food trial helps to isolate dietary contributors and can guide long-term management.

What Is a Food Elimination Trial?

A food elimination trial involves feeding a dog a simplified, novel, and controlled diet for a minimum of 8–12 weeks . This typically includes:

• A single novel protein (one the dog has not eaten before)
• A single novel carbohydrate source , or none if feeding a raw diet

No other foods, treats, supplements, or flavoured medications are allowed during the trial.

Following the trial period, previously fed foods are systematically reintroduced one at a time to monitor for return of symptoms (the “challenge” phase).

Important Nutritional Considerations

Elimination diets can be nutritionally limited due to their simplicity. It is important to:

• Ensure the base elimination diet is nutritionally adequate , especially if fed long term
• Monitor for nutrient deficiencies , which may contribute to skin inflammation or delayed healing
• Reassess and balance the diet once trigger foods have been identified

Working with a veterinarian or canine nutrition professional during this process is highly recommended.

Summary

A structured elimination diet trial is a gold-standard method for identifying food-related causes of allergic skin disease or chronic GI signs. While not a cure, this approach can significantly improve quality of life when food hypersensitivities are contributing to inflammation or discomfort. Future blog entries will outline how to structure a raw or cooked elimination diet and what to expect during the challenge phase.