Shih Tzu dog hereditary health and health testing

Shih Tzu dog hereditary health and health testing

The Shih Tzu dog is a small and very popular toy dog breed that originated in Tibet, and that has a distinctive long and flowing coat that is often tied in a ponytail on the head to keep the hair from obscuring the dog’s eyes. The Shih Tzu can stand up to 11” tall at the withers and weigh up to 7.25kg, with males and females of the breed being around the same size.

Their coats can be seen in a wide range of colours, including white, black, black and white, brindle, blue, grey, brown, and gold, and their fur is very fine, straight and long with two layers. Compared to most other breeds of dog, particularly ones with similar length coats, the Shih Tzu does not shed heavily, and as such, they may be worthy of consideration by people who are prone to canine allergies. The coat can be either wavy or coarse, and requires a lot of brushing and grooming to keep it in good condition, as well as regular trips to the grooming salon for tidy ups.

If you are considering buying one of these small and very popular and widely owned toy dogs, it is important to do as much research as possible before committing to a purchase. In this article, we will look at the hereditary health and longevity of the Shih Tzu breed, plus recommended health tests for the breed too. Read on to learn more.

Shih Tzu longevity

The average lifespan of the Shih Tzu displays a significant range of variance, with surveys returning the average as anywhere between ten and sixteen years. This makes it difficult to draw any general conclusions about the breed health and wellness based on their longevity alone, as dogs of the breed represent both ends of the scale, with ten years being below the average for all breeds of a similar size and build, and sixteen years being well above the average.

Genetic diversity

The coefficient of inbreeding statistic for the Shih Tzu is 5.4%, which falls comfortably within the accepted norm of 6.25% or lower that is the ideal for pedigree dog breeds. This indicates the fact that the Shih Tzu breed is popular and diverse, and that a high degree of inbreeding is not necessary to maintain the breed in perpetuity.


  • The coat of the Shih Tzu requires a lot of grooming and care to keep it in good condition, as otherwise it will soon become matted and tangled.
  • The short head of the breed places the breed at risk of brachycephalic ocular syndrome, due to the position and shape of the eyes, which may lead to a range of eye problems.
  • Problems with the nostrils and normal breathing can also occur due to the overly short muzzle of the breed.
  • The breed’s small mouth can lead to dental overcrowding and teeth problems.
  • The general shape of the Shih Tzu, including their static ears and curled tail can pose problems in terms of effective communication with other dogs.

Health testing for the Shih Tzu

The British Veterinary Association and The Kennel Club advise that dogs of the breed be DNA tested for renal dysplasia, a kidney condition that is prevalent across the breed. Pre-breeding health screening is advised for potential breeding stock.

Other health issues

While renal dysplasia is the only health condition that is considered to be both prevalent within the breed and testable prior to breeding, the Shih Tzu is actually a breed for which a fairly long list of other potential health issues can be found as well. There is no definitive way of finding out prior to purchasing if such conditions are likely to occur, but finding out as much as possible about the health of the parent dogs can help the prospective buyer to make an informed decision.

Some health issues known to affect the Shih Tzu breed include:

  • Necrotising leucoencephalitis, an inflammatory brain condition that often proves fatal.
  • Dry eye, or keratoconjunctivitis sicca.
  • Perianal gland tumours, a type of cancer.
  • Cataracts of the eyes.
  • Distichiasis, a condition in which the eyelashes grow a second row, which can rub on the eye.
  • Entropion of the eyelids, in which the lids turn inwards and rub on the eyes.
  • Cushing’s syndrome, an overproduction of the body’s corticosteroids.
  • Congenital portosystemic shunt, a circulatory disorder in which blood bypasses the liver, allowing toxins to build up within the bloodstream.
  • Atopy, a hypersensitivity to certain protein particles, including pollen.
  • Mitral valve degeneration of the heart, a type of heart disease.
  • Patellar luxation of the knee cap.
  • Intervertebral disc disease, which can lead to pain and weakness due to compression of the spinal cord, and which may lead to paralysis.
  • Urolithiasis, the formation of crystals and stones within the urine.
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