They are both over a year old. I got them progably March of 07. My dalmation male was already an adult when I purchased him. My harly was a baby, but she has grown and is about the size of the male now. She seems to be doing well, they are both very active at night and eat regularly. So, I hope that I did all of that right. I didn't put them together until I knew the younger female would be big enough.