Tag archives: cone receptors

Preventable Inherited Eye Diseases of the Chinese Crested

Preventable Inherited Eye Diseases of the Chinese Crested

Despite being one of the most recognizable dog breeds in existence due to their unique physical attributes, the early history of the Chinese crested is a bit mysterious due to a lack of adequate written records. Though early hairless dogs have been documented in Africa, Central and South America, and Asia, the relationship between these dogs is not well understood. Evidence to suggest that they may be related is found in the fact that at least 3 hairless breeds originating from different continents (Mexican hairless, Peruvian hairless, and Chinese crested) are all known to inherit the same FOXI3 gene mutation responsible for their hairlessness. It is most likely that a common ancestor to the hairless breeds developed a spontaneous FOXI3 mutation that was later passed to the individual breeds as they were developed. It is theorized that early hairless dogs travelling on shipping routes with their human companions played a role in the spread of the trait to numerous locations in the world.

In addition to genetic mutations responsible for particular physical traits, like other purebred dogs, Chinese cresteds are known to inherit some genetic mutations responsible for causing inherited disease. Inherited diseases of the eyes are of particular concern ...

Shades of Gray: What Your Dog Really Sees

Shades of Gray: What Your Dog Really Sees

It’s often thought that dogs see in black and white – or shades of gray. That common thought isn’t completely true. While dogs do see shades of gray, they also see hues of blues and yellows. In humans, they’re somewhat comparable to a male who is red-green color blind.

In an article by Dr. Donna Spector, the vision of both dogs and cats is broken down and explained very well. In short, dogs and cats both see better in low-light conditions than humans, with cats taking the crown as night stalkers, by picking up on motion and contrast.

Dogs have better peripheral vision than both humans and cats, with some breeds that have short faces and wide-set eyes, such as the English bulldog and pug, able to see in excess of 240-degrees around themselves. Canines also have better overall vision than cats – about 20/75 as compared to felines that score somewhere between 20/100 and 20/200.

Both cats and dogs pick up on motion in low light better than humans. They also see contrast between shades of gray better – which combine to both help and hinder dogs, depending upon the task at hand.

A hunting dog ...