When you take your kitten home you should stick rigidly to the diet sheet that the breeder will have given you until the kitten is completely settled. After that you can start to change the diet if you wish but you should do so gradually. The most common mistake that people make is to feed what they think is best.
Taking this approach doesn’t guarantee that stomach upsets will be avoided but it does minimise the risks. If you do nevertheless encounter problems you should give the kitten a bland diet for a few days: small portions of fish and rice or chicken and rice are ideal. You should then be able to start gradually reintroducing the normal diet within a few days. If the kitten’s condition deteriorates, you should speak to your vet because the kitten could become dangerously dehydrated.
Another common problem is the belief that milk is an ideal food for cats but, in fact, it also can upset their stomachs. Milk substitutes that don’t cause such problems are available but they are not really necessary: all that is needed is a plentiful supply of fresh water at all times.