I have first hand experience for you. We have a 80 lb lab who's almost 3 and a 11 lb doxie who's almost 9 mths now. Guther the doxie is best bud's with Sammy the Lab. If you want to find one you just look for the other one. They are like peanut butter and jelly. They play, play and play...... To be honest here is what I will tell you. 'Sometimes', Sam mops the floor with Gunther (sweeping him from one side to the other back and forth by his collar) BUT, Gunther gets up and comes back for more. He's FEARLESS!!!! He BITES SAM, he picks on Sam. He bites Sam's LIPS, LEGS, what ever he can get a hold of. He LOVES biting his ears and NOT letting go. So Gunther has his way of getting even.
Also, 'sometimes, we have to tell Sam to be 'careful' he gets SOOO excuberant. He just gets so excited when he plays. Gunther DOES YELP cause Sam puts him ALL the way in his mouth. However, I yell and Sam lets go. Also, if I don't yell and Gunther yelps, Sam lets go. He's NOT hurting him he's like I said; excuberent. BUT, I want to be honest with you. HOWEVER, I wouldn't have it any other way. Gunther will YELP one minute and COME RIGHT BACK BITING SAM... SO he's NOT HURT. Sam has NEVER, EVER HURT HIM.
EVER!!!!!!! They sleep together and when Gunther wants something Sam has he goes and takes it and Sam lets him.
At night we go down stairs to watch TV and Sam is in my lap next to me and Gunther is on top my lap right next to me. Then when it's bed time, him and Sam share a bed. BESSSST thing I ever did for my Sam. We do have another dog, a Shar Pei and EVEN her she's really good with my doxie and she's 45 lb's. and she's the princess of the house and runs the boy's.
So IMHO, yes.... IT can be done. BUT, it depends on the temperment of YOUR dog. Sam is fun loving and easy going. My Shar pei is MORE uptight and EVEN she accepted him. She's VERY jealous natured and still she decided she liked him. But it took her a couple of weeks before she decided.
Anyway, good luck to you in your choice. I hope you decide to do it. Any questions feel free to ask.
Here's a pic of Sam and Gunther playing Tug of War their "favorite" game they play EVERY day..... Sam will get him going so fast Gunther will fly through the air sometimes. Gunther just loves it....TJ
Here's our pic of sitting on the chair at night. Nice and comfey....