It is suggested that if the puppy does not have a mom to drink from to order a product called "mother's milk" for dogs.you can find it online and at some specialty pet stores.if you accidently gave it cows milk do not be scared.it will just have "the runs" for awhile.If affording "mother's milk" is hard and you have nothing else here is a idea.I used to work at a shelter and we would use bottled water(no impurities) with milk(cow) and bottle feed the pups.check google to see what key nutrients would be missing from the milk for the dog breed and ask how to supplement.aspca dot com is awesome for help.good luck :)
No way, they can get really really sick. However, some dogs/puppies are not that effected. I don't suggest you try to feed them cow milk.