OMG! I've never realy paid too much attention to coopers size, I just assumed he would be 3.5 like his breeder estimated. He is now 19 weeks and yesterday at the vet he weighed 1 pound 13 ounces. I didnt think anything of it. But since I knew his weight I checked it on the weight chart. If that is right he wont make it to 3 pounds. He has seemingly stoped growing! I never wanted a tiny tiny chihuahua. But I guess some get bigger then expected and some smaller.