I'm the same way, except with cats. I had 2, 4 year old male cats and this summer we adopted Socks. He was "adopted" with my brother's cat as his mama barn cat abandoned him.

My cousins threw him out when their new dog didn't get along with his adopted mom. The barn kitties picked on him, so I brought him in and adopted him.

Hokie and Ollie growled...as did he for a few days, but now they wrestle and play just like brothers. I'd bring in another one if I could...but not only would my family disown me...so would hubby. lol

Animals adjust. You'll be fine. Send pictures!