Properties TROVET Hypoallergenic HRD (Horse) Cat contains a single protein source (horse meat) and 1 carbohydrate source (rice). In addition, the diet contains all essential nutrients in the optimal amounts. The diet is fed to the cat as the only food for 3 - 8 weeks. Not all complaints will reduce or disappear immediately. For example, skin conditions improve slowly. When the complaints diminish or disappear completely, the diagnosis of food hypersensitivity has been made.