The Ojos Azules is a new breed of domestic cat, discovered in New Mexico among feral cat populations. The first Ojos Azules discovered was a tortoiseshell named Cornflower, found in 1984. She was bred to males without the trait deep blue eyes which proved to be dominant as all her kittens. The breed was founded and named Ojos Azules, Spanish meaning ‘Blue Eyes’.
Ojos Azules are distinct for their deep blue eyes. Unlike the blue eyes seen linked to the genes in bicolour cats and cats with point colouration, both of which suppress pigmentation, this gene is not linked to any certain fur colour or pattern, giving the opportunity to have cats with dark coats and blue eyes. The depth of colour in the eyes is greater even than that seen in a Siamese cat and does not cause squinting, deafness or cross-eye. They are a very rare breed. In 1992, only ten were known. No true standard has been made, and no cat registration recognises them. So far, only cats expressing the deep blue eye gene have been called Ojos Azules. It was recently discovered that cranial defects may be linked to the gene, and breeding was temporarily suspended.
Following a genetic investigation by Solveig Pflueger, breeding resumed in a small way with attempts to breed Ojos Azules without the lethal genetic defects. It was discovered that when the gene is homozygous it causes cranial deformities, white fur, a small curled tail, and stillbirth. However, when the gene is heterozygous, it avoids those lethal genetic mutations. The result is that breeders must cross the blue-eyed cats with non-blue-eyed cats, assuring a litter of about 50/50 blue/non-blue-eyed kittens. Though only half of the kittens are then part of the Ojos Azules breed, this avoids having much of the litter comprised of deformed, dead kittens.
One indicator of the Ojos gene is a flattened tail-tip.