Ruby is 8 months old and weighs around 3.9 lbs. My vet, whom I totally trust, doesn't want to spay her until she is at least 4 pounds. What if she never gets to 4 pounds? She has been at 3.9 for a good month or two. He said if we have to wait until she's a year old, so be it. He also doesn't see any problem with her going through one heat. I'm glad he's being cautious, but will there be any problems with her going through a heat. What do you all think? Also, when should I expect her first heat? Thanks!!