I can give you first hand info on that. Been there, done that. We had a 9yr.old 85 pound black lab ( I tearfully say had as we had to put him down last month due to Cushings disease) TJ, our big guy was grieving from the loss of his "sister" 2 months before and didn't want to do much of anything. We got our little Belle who is a Morkie and she weighed in at 2 pounds. When we brought her home TJ looked at us like "she's not staying, right?" It didn't take Belle long to let TJ know that he was her favorite toy. Morkies do what we call "zoomies" where she runs all over as fast as her little legs can go. She would do that using TJ as her springboard! He just rolled his eyes. They did play together, she even had him playing with toys again. If she wanted a bully stick that he was chewing on, she took it and he just waited till she was done with it. We totally trusted TJ with Belle but just for our peace of mind we put Belle in her crate when we would go somewhere. That way we knew that nothing would happen. TJ would just lay by her crate and sleep. My hubby says he thinks TJ would tell her "mommy and daddy aren't coming back again, all the treats are mine!"
Belle was very happy to see us when we got home. Just introduce them slowly and give your lab lots of attention, they kind of work things out themselves but just be watchful. We never saw any signs of jealousy but TJ was a special dog. I would say a female Yorkie may be better as I've heard and read about the leg lifting with the males too. Mostly, I just love dressing Belle all girly.
