Quite simply, no dairy product is a species-specific food. No where in the wild canine/feline world would there be milk/cheese/cottage cheese to eat. True, once in a great while they might get a hold of a lactating mother or milk-fed baby, but that would be a rare occurance and there isn't that much milk in them anyway (nothing like the 100 or so pounds of milk per day from a milking Holstein cow). Also, neither cats nor dogs have the enzyme, lactase, that is needed to breakdown lactose, the sugar in milk. Some individuals are able to tolerate dairy products, but it certainly isn't good for them. Humans have varying levels of lactase.

If you aren't able to get organically-produced milk, are you aware of what is IN milk? Pesticides, growth hormones, antibiotics and other various assorted chemicals all given to the cow can come through in the milk. I have heard that 1/2 of all children's exposure to antibitics comes from MILK, not an actual prescription. Scary thought. BGH, a hormone used to increase milk production, is linked to cancer formation, and comes through in milk.

Many pets with allergies have allergies to dairy products (this includes yogurt, which is usually mis-labeled as being nutritious). If they aren't allergic to the foreign things in milk like the proteins, chemicals and hormones, then the dairy triggers allergies to other things. So avoiding any dairy not only helps your animal not be allergic to it, it helps decrease other allergies. If you yourself have allergies try dropping all dairy and grains from your diet and see if that doesn't help your allergies tremendously.

Calcium isn't even that absorbable from milk. Humans and dogs/cats alike can all get great levels of calcium from vegetables. Dogs/cats can get even more through bones (raw of course).

So why even feed dairy products?? There is no reason, except that's the trend of the moment. I myself have stopped drinking milk and am slowly but surely cutting out all other dairy products from my diet. My animal companions are all dairy-free.

For an interesting website on a lawsuit by 2 reporters who sought to uncover the use of BGH, see BGH Bulletin-Hidden Danger in Your Milk? Quite an interesting site.