Hello,I have 2 Shih Tzus both are 7months old and they are male & female. when they were still at the store. they feed them " Beef Pro" . after we bought them we feed them the same dog food but it didn't last long ( about 4days only). They started NOT eating the dog food , but we prepared the food the same way the store did.We feed them Eukanuba , Pedigree(pellets and chicken/beef chunks) , and 2 other dog foods.But they move very very normal and they feel very very healthy. Me & my mother, being concern, we searched for homemade dog foods, we learned the recipe and we cooked it. At last they ate the food! but once again, it didn't last long. we gaved them variations. Chicken Liver , & many other internal organs. What do we really have with our shih tzus? do they have some sort of sickness?what would you recommend for this 2 dogs ? + we have a problem , we cant control them if they are in heat. we dont want to (castration) do it to him. The problem there is that they are sisters & brothers . what would be your thoughts ?