So is it ok to feed your cat or dog milk or milk products?

Answer:
Similar to humans, dogs and cats can suffer from lactose intolerance and unfortunately for our companions it is a very common problem. Lactose intolerance is essentially the absence of the beta lactamase enzyme which assists in the breakdown of sugar found in milk. Without this enzyme, the undigested sugar builds up in their intestinal tract, leading to diarrhoea and vomiting.