In the "So What Else is New?" department, an article published by the Australian Broadcasting Corporation describes a study performed to see if dogs have a preference for certain temperatures of drinking water.

The pooches were offered water three times a day from three separate bowls. [...] The water temperatures were 15°C, 25° and 35°. After two weeks, Wendy found that the dogs showed clear preference for the water at 15°.

15°C equates to 59°F. Not exactly "COLD cold", but cool. However this article was written in the context of keeping dogs cool in hot weather. I imagine if a dog was shivering cold, it might go for the warmer water. So, maybe dogs are not so different from people.

The same article goes on to compare how a vegetarian diet versus a meat diet affected a dog's health. The result, no difference.