Dogs and humans have shared an extraordinary bond for thousands of years. DNA evidence has shown that dogs are descended from ancient wolves and were domesticated 100,000 years ago. It is believed that canine service work dates back to the pre-historic age when dogs helped nomads hunt for food. As time went on, their function expanded to herding and guarding farms and crops, and since the earliest human settlements, canines have provided us their protection, their vigilance, and their devoted companionship. Today, they may be classified as "working dogs." 

"Dogs are macrosmatics, meaning that their sense of smell, or olfaction, is highly developed," said Brian Collins, D.V.M.'94, extension associate at the Cornell Richard P. Riney Canine Health Center. 

Visit here to see the rest of Collins' comments in the July issue of Metropolitan Airport News.