Dogs are naturally lactose intolerant they don't naturally produce the enzyme that breaks down so therefore they shouldn't drink cows milk which has the sugar lactose in it . They will suffer severe stomach cramps, discomfort ,and diahrea or loose stools , which can lead to dehydration which if prolonged can cause death!!!!!1
Nothing will happen it is just milk!
They will grow healthy and strong! Cow's milk is more nutritious than puppy milk. Dog milk contains lactose too!
They will probably start developing some fat little tummy's.