Why do shih-tzu dogs have so many problems with their eyes and tear ducts?
Shih Tzu have several genetic eye diseases. One of the most important diseases in this breed is due to the brachiocephalic skull. Brachiocephalic dogs have shortened noses and very prominent eyes due to shallow orbits– the bony socket that surrounds the eye. The shallow bony orbit in the short-nosed dog causes the eyeball to be in a more prominent position, giving the appearance of being larger than dogs of similar sizes with longer noses. Along with this skull conformation, there is the problem of lagophthalmos– an inability to properly close the eyelid over the cornea. Lagophthalmic dogs generally have an enlarged palpebral fissure– the space between the upper and lower eyelids. Brachiocephalic dogs classically have all their cornea exposed when the eyes are open and generally they have the white of the eyeball exposed also. This conformation causes two clinically serious consequences to the Shih Tzu. First they are more prone to exposure keratitus– inflammation of the cornea. In
