A variety of birth defects are associated with the allele for leucism, including crossed eyes, cleft palate, spinal deformities, club foot, immune deficiencies, heart and kidney defects, hip dysplasia, hind-limb paralysis and mental disabilities. The practice of inbreeding generations of lions and tigers to produce leucism makes all the offspring (not just the rare white ones) more likely to suffer from this myriad of congenital illnesses and defects. For example, all white tigers are cross-eyed, even if their eyes appear to be fine, because the same gene that causes leucism also wires the optic nerve to the opposite side of the brain.
In addition, inbreeding increases the chances of stillbirths and infant mortalities, especially with further inbred generations. According to Big Cat Rescue, about eight in 10 white tigers die from inbreeding-related birth defects, and even the survivors tend to exhibit severe deformities and die young. Because they are so heavily inbred and almost always documented in captivity, white tigers and lions are also more likely to suffer from depression, like the above white lion held captive at the Karachi Zoo to attract more visitors.
Rare big cats are exploited by fake sanctuaries and irresponsible zoos.