I owned a shih tzu for 15 years. They really are a great breed. Most of the problems have been bred out of them through centuries of selective breeding in China. However they do still have a couple of issues they are prone to.

First of all, they have a tendency toward eye problems, most specifically dry eyes and abrasions. Make sure you keep their eyes clean and keep the hair trimmed or at least groomed around their eyes to keep hair out of them. If you see any discoloration on the conjunctiva (the white part), consult a vet. Abrasions show up as dark, grayish spots on the white parts of the eyes.

Secondly, if you live in an area where your water contains a lot of minerals, you may want to put a tablespoon of vinegar in their water dish to help neutralize these minerals. My shih tzu almost died from urine toxicity because a rock of crystalized minerals began forming in her bladder. She constantly felt like she needed to go and would have accidents constantly. When I noticed the blood in her urine, I took her in and she was, according to the vet, two weeks from death. A small operation later to removed the lump and she was all better and lived an additional ten years.

Thirdly, due to their thick coats, they need their hair either kept short or groomed on a daily basis. Otherwise, they could end up with skin infections.

Your shih tzu may show signs of sinus problems, but not to worry. Their short noses make them prone to sneezing and even mildly runny noses. This is normal for a shih tzu.

Other than the above, the shih tzu is a very hardy breed, very playful, and very rough and tumble, not at all like they look. They are very active dogs, but can also be great lap dogs. In my opinion, shih tzus are about hte most well-rounded dogs ever. They were originally bred in China to be royal pets and it wasn't until the 1940's that the first shih tzu was successfully smuggled out of China.

What is said to be hereditary to the Shih Tzu are eye problems. According to The American Shih Tzu Club they have several ocular disorders. One is problems with closing the eyelid over the cornea, they are more prone to inflammation of the cornea, and in severe cases ulcers develop and can cause the cornea to rupture.

They also get eyelash diseases, causing ocular irritation and hairs can emerge through the eyelid that causes pain as exhibited by squinting and facial wetness.

Another eye disease that Shih Tzu's get are cataracts and dry eye.

A recommend book by The American Shih Tzu Club is Ocular Disorders Proven Or Suspected To Be Hereditary In Dogs, by the American College of Veterinary Ophthalmologists. The book is in layman terms and can help identify problems you may have with your pet.

Other common ailments with Shih Tzu's is as follows: ear infections, and hip dysplasia.

One sure advice for prevention is to make sure your pet gets regular visits to your vet.

I found a couple websites to help you with your research. Hope they help. :)

http://www.gopetsamerica.com/shih-tzu/shih-tzu-health-problems.aspx
http://www.yourpurebredpuppy.com/health/shihtzu.html
http://www.mydogbreed.com/shih-tzu/shih-tzu-health.php
http://www.yourpurebredpuppy.com/reviews/shihtzu.html

I myself have a Llasa Apso and he sometimes gets coughing spells and he sneezes a lot, which is normal according to the vet. Just be careful about what you feed them. They should NEVER be fed people food and when your dog is outside make sure they don't EVER put a toad in their mouth.....it can be very posionous. If it does happen wash their mouth out for at least five minutes. They may start to foam at the mouth BUT DON'T WORRY as long as you wash their mouth out ASAP then your dog should be fine. Their eyes get watery a lot and that is normal UNLESS it starts to close shut. Then that means it might be pink eye.

According to http://www.trainpetdog.com/Shih-Tzu/about-shih-tzu.html, some Shih Tzu dogs are vulnerable to ear, eye and respiratory problems. They are prone to Spinal disc disease, entropion , portacaval shunt, renal dysplasia, progressive retinal atrophy (PRA), patellar luxation, and trichiasis.