Are dogs lactose intolerant?What are the symptoms and effects if a 5 month old puppy drinks milk?

Basically because the make-up of cows' milk is different to that of a ******, dogs can't tolerate it. Some can have the occasional drink of milk (in tea for instance) without showing any reaction however. Much as a puppy of 5 months doesn't need milk any more, you can use goats milk, which is close in make up to that of a ******. Diarrhoea would be seen, as a reaction to cows' milk.