Obedience Trial: An event held under AKC rules at which a leg toward an obedience degree can be earned.

Obesity: The condition of being obese; increased body weight caused by excessive accumulation of fat.

Oblique Shoulders: Shoulders well laid back.

Obliquely Placed Eyes: Eyes with outer corners higher than their inner ones.

Occipital Protuberance: A prominently raised occiput characteristic of some sporting and hound breeds.

Occiput: Dorsal, posterior point of the skull.

Odd-Eyed: Eyes of different color, such as one brown eye and one blue eye.

Old English Sheepdog: An English breed of sturdy dog having a docked tail and a thick, shaggy, bluish-gray and white coat with fur that hangs over the eyes.

Omnivore: A person or animal that feeds on both animal and vegetable substances

On-Dog Identification: A system of tagging, tattooing, or microchipping used to uniquely identify a dog.

Ophthalmic: Of or relating to the eye; ocular.

Orange Belton: See Belton. Color definitions may vary by breed. Always check the breed standard for the definitive color description.

Orthopedic Foundation for Animals (OFA): Organization, established in 1966, that developed and maintains a registry of hip dysplasia in dogs. Dogs with OFA numbers are rated and certified free of canine hip dysplasia. This rating applies for the life of the dog. In order to have OFA on AKC records, a dog must have permanent ID.