By Jo Ann White
Users of this web site often ask questions about blue eyes in Shih Tzu. In most cases, it turns out that people were looking at very young puppies whose eyes had barely opened and were still slightly cloudy, giving them a temporary bluish cast. A similar cloudiness that appears blue in some lights can be seen in adult Shih Tzu with cataracts, corneal ulcers, or various forms of inflammation of the clear part of the eye (keratitis).
What veterinarians commonly refer to as "blue eye" (interstitial keratitis) is the result of infectious canine hepatitis or a reaction that occurs, rarely, among dogs vaccinated against the disease. It is caused by an inflammation deep in the cornea that creates a bluish-white film over the clear part of the eye, generally appearing 10 days to two weeks after infection or inoculation. Infectious canine hepatitis is not the same as the human disease known as hepatitis. Highly contagious, it is spread to other canines by contact with the urine, stool, and saliva of infected dogs. Most severe cases occur in puppies. The disease may lead to death due to damage to the liver, kidneys, and blood vessels; among the symptoms are bloody diarrhea, tonsillitis, lack of appetite, jaundice, and subcutaneous bleeding. Mildly affected dogs may be lethargic and reluctant to eat. Generally, hepatitis-related blue eye dissipates in a few weeks. Very few dogs have eyes that remain permanently clouded. Nevertheless, the risk of blue eye reactions has led the American Animal Hospital Association to discourage the use of MLV or killed Canine Adenovirus-1 (CAV-1) inoculations. Instead, the AAHA 2003 and 2006 vaccination guidelines recommend using MLV parenteral CAV-2 vaccines, which give the same protection against both kennel cough and hepatitis as CAV-1 but involve less risk.
Blue eyes that persist throughout life can occasionally be found in Shih Tzu. Such blue eyes (actually, often dark or light gray rather than bright blue) are found in blue dogs. Blue Shih Tzu lack a needed color gene for black. Their color is therefore dilute; they also have blue pigment on their muzzles, noses, lips, footpads, and eye rims. Like liver-pigmented dogs (which have light brown eyes and pigment rather than the more common black), blue Shih Tzu are rare, but are perfectly acceptable in the show ring. All colors and markings are permissible in our breed. Nevertheless, blue eyes are unacceptable in the show ring in any color except blue. Light eyes of this kind do not affect vision, and blue-eyed Shih Tzu make fine pets.
Likewise, very young puppies may display considerable white in the inside corners of the eyes; this frequently corrects itself once their eyes are strong enough to focus properly. In any case, the vision of dogs showing large amounts of white in the inside corner of one or both eyes or white all the way around their eyes is not impaired. In the show ring, however, excessive eye white that detracts from the desired warm, sweet expression is penalized in all colors. It is often the result of a too-shallow eye socket or a skull that incorrectly falls away behind the eyes.
Reprinted from the American Kennel Club Gazette, September, 2007