We had Lexi spayed at 6 months. Before her first heat. She only weighed about 3 1/2 lbs. She did great...no problems at all. Unfortunately my vet did not want to do her teeth at that time as he wanted us to see if they came out on their own. Now she has to go on Tuesday to have them removed as she is now 8 months and up to 4 lbs now...she's getting big LOL Again, I get to be a nervous wreck