Viv, it sounds like you will have no problem at all. But one thing I need to warn you about (happened to me)...
you need to be prepared to get less attention from
Snickers 
. My first furbaby was a German Shorthaired Pointer - loving, brilliant, and a member of our family. I prepared him by letting him lay on my pregnant belly (cutest thing EVER!), sniffing all of the new baby stuff, and bringing home the baby's first hospital blanket to him. WELL, let me tell you...he was Daddy #2 to this baby girl. Loved her to pieces, and would sleep under her crib. When she cried, he would come tap me with his wet nose to be sure I'd attend to her. When I walked into the room holding her, he would kiss the baby first, THEN me
. He watched over this baby like a guardian angel, God rest his soul. Bottom line, I think your heart and relationship with Snickers is in the right place, and with inclusion throughout the process, he will one day make an excellent big furbrother!