FOOD ALLERGY IN THE DOG AND THE CAT

Food allergy in the dog or cat can only be described as non-seasonal d ermatitis accompanied by scratching. When the term 'food allergy' is u sed, an immune-mediated reaction is not always meant, although the ter m would suggest that it is. The frequency of occurrence of food allerg y is unknown, with the literature giving widely differing percentages. Type I and type IV hypersensitivity reactions probably play a role in the pathogenesis, although a type III reaction is also thought to be involved. Gastrointestinal disturbances and skin complaints are sympto ms of food allergy, and scratching is nearly always mentioned as the m ost common sign. The diagnosis can only be made by feeding the animal on a hypoallergic diet, which must be given for several weeks. Diagnos tic tests are unreliable. The patient should not have been previously exposed to the ingredients of the hypoallergic diet. As 'home-made' di ets may be deficient in minerals, vitamins, and essential amino acids, these ingredienst must be supplemented if the diet is to be maintaine d for a long time. The prognosis of food allergy is good if the causat ive ingredient is identified. It is important the animals' owner is gi ven through instruction. Medicines have little effect on food allergy.