I was pretty puzzled when I found this out but my 7 year old Toy Poodle has milk in her! We do not own any other small male dogs that could get her pregnant. Besides that she stopped coming into heat along time ago. I don't know if this has anything to do with it but (not knowing) we bought her from a puppy mill along time ago. I squeased all of her teats, and everyone has milk in it. She was never spayed and did mate with a black miniature poodle but never had puppies, so there was no reason to get her spayed. I was just curious to know what this is exactly. How could a dog this old and not even pregnant have milk in her? It's the craziest thing. Hope I'll get some answers...Thanks