Scientists change how we calculate dog years

Dog lovers have been incorrectly calculating their pet's age. They have been working out their dog's age in "human years" by multiplying by seven. However, researchers at the University of California have come up with a new formula. They say it precisely finds out canine age. The new method needs more than simple mental arithmetic to work out a dog's age. It involves comparing the changes of the DNA of dogs and humans. The scientists regard such DNA analysis as the best way to measure the ageing speed of dogs and humans.

The researchers analysed blood samples from 105 Labradors. After some number crunching, they created a graph to show the different rates at which dogs and people age. A one-year-old dog is similar to a 30-year-old human, while a four-year-old dog is like a 52-year-old person. A researcher said when a dog turns seven, its ageing slows. He said this made sense, and that: "A nine-month-old dog can have puppies, so we already knew that the 1:7 ratio wasn't an accurate measure of age." The new formula doesn't fully address the fact that different breeds of dog age at different speeds.