I think dairy given as a treat is fine once and awhile. Again, it is giving a variety of foods that acheives balance. Pasteurization as mentioned above kills bacteria. Pasteurization leads to arthritis is a false claim. I have never read or heard of this.
Arthritis is thought to be an allergic reaction amongst many other things.
It is a personal choice to feed dairy products to your pets. Make sure you make an informed decision prior to deciding. Dogs are carnivores Yes dogs are carnivores. There are many degrees to carnivores. They need vegetables as well as meat to provide the correct metabolism and pH of body fluids.