Toys are hard to train in general and don't have good behavior. It gets even worse when you baby them.
Some people say, I don't need to train, I won't do sports, I won't show him...and they get a little brat. Puppy training school and obedience training will come in handy. It isn't just sit, down, ect. You learn come, stop, sit, down, wait, no bark, leave it, ect. Can you see how they come in handy?
So, we are fighting that teacups are small. Research them before you start fighting!
Oh, I am not saying not to get a toy dog, just saying to research before buying. That is why there are so many dogs in the humane societies and rescues.[/b]
Alright, I have to disagree. Not all toys are hard to train. Case in point. My Pomeranian, CiCi, a definite toy, has been very easy to train. I will agree, however, that people need to do research before buying any dog, be it toy or any other. I don't train CiCi the same way I would train another dog. CiCi is a headstrong dog, but once she realized that I was the head of the pack, she takes orders from me very well. One of the first things I did with her, however, was take the Volhard puppy aptitude test. She scored mostly 2s and 3s, so she's quite a dominant dog, and needed a firmer hand for training. The results of the exam determine how you approach training the dog. Knowing what makes her tick, made my life, and ultimately hers, much easier. She is a well-mannered dog, and there is ample time for babying and snuggling. Just take wone wook at that wittle face on my avitar, and you'll know that wittle girl was built for snuggle-poo wuv, wuv.
Now, for the topic in question, I personally wouldn't own a tea-cup variety of any toy breed (I personally like a little more dog and not worrying about hurting it by accident), but I don't know enough about them to make a generalization about their health. From what I've read and heard over the years, they tend to be very fragile and for the most part, in poor health, but I'm just relaying what I've read. I am sure that there are Tea-cups running around healthy as a horse. The breeder where I got CiCi has made a definite decision about Tea-cup versions of Pomeranians and refuses to breed a female that's under 8lbs. 8lbs is actually over the breed standard for Poms, but her puppies don't have the health problems that smaller Poms tend to have. CiCi is a reflection of this, I believe, wise decision. CiCi was the smallest of that litter at 6lbs (still on the large end of the Pomeranian scale), though she may be more, I haven't weighed her in a little bit. She has perfect teeth, and no evidence of patella luxation. She enjoys 2mile+ walks and has much more stamina than other smaller dogs I've seen. Actually over 100 years ago, Queen Victoria's prize-winning Poms were all over 7lbs and earlier versions of the breed were 15-30lbs! I think in addition to the toy classification of 3-7lbs, a larger size classification should be introduced, say between 8-15lbs. One can dream. Like your schnauzers, she is a boisterious, intelligent, small dog that is a perfect companion pet for someone in an apartment. The shedding isn't as bad as I thought, but I groom her every other day, so that may have something with it.
So please don't generalize about dog breeds. I could have easily said that Schnauzers are stubborn, nippy, and yappy. This has been my experiences with the Schnauzers I have encountered. But, I know that Schnauzers weren't bred to be that way, and are awesome dogs. They were very high on my list when I was researching breeds. The same goes for Pitbulls, who have such a bad reputation. All the pitbulls I have encountered have been marshmellow dogs that love a good belly rub more than anything in the world, but I don't want to open another can of worms, so I won't discuss pitbulls further, that was just an example. I think a lot of this boils down to the owner of the dog and how they take care of it. As I stressed in the beginning of my post, every prospective dog owner must research a breed thoroughly before buying. I was looking into Poms for a year before I purchased CiCi from a reputable breeder.
This is my two cents worth.