Adverse food reactions are categorised as reactions initial symptoms and inflammation have subsided (Lomer 2015). to dietary ingredients by specific individuals which are harmless to others. This term covers toxic reactions, food allergies and food intolerances. A food allergy is an immune system response to one or more proteins that have been ingested by the pet. These proteins are referred to as antigens because they cause antibody production, and an allergen is an antigen that causes an immune reaction and is therefore allergy-inducing (Cave 2006). In an allergy response, the immune system incorrectly recognises the food protein as an antigen and causes a chain reaction in the body, commonly an immunoglobulin E (IgE) mediated response which leads to allergy symptoms. A food allergy develops in two stages: when the allergen is first consumed, it triggers the production of IgE antibodies which are specific to the protein ingested. This is known as the sensitisation period, and these antibodies bind to basophils and mast cells. If the allergen is consumed again, it binds to its specific IgE antibodies and cross-linking of these antibodies causes release of histamines and leukotrienes, chemical mediators, from basophils and mast cells activated during the cascade of reactions caused by the immune response. Cross-linking of receptors and allergens is needed to activate mast cells and basophils, meaning that two or more IgE antibodies need to bind to one allergen to cause a reaction (Matsuo et al. 2015; Waserman and Watson 2011). When a pet develops a food allergy, it is most commonly as a result of long-term exposure to a protein (Raditic et al. 2011).