New research into canine DNA is challenging the old “multiply by seven” rule — and suggests dogs of the same age may actually be ageing at very different rates. New research into canine DNA is challenging the old "multiply by seven" rule — and suggests dogs of the same age may actually be ageing at very different rates. SYDNEY, AUSTRALIA — For generations, dog owners have been told that calculating a dog's age in human years is simple: multiply their age by seven. The research strengthened the evidence that measurable molecular changes occur as dogs age and demonstrated that canine epigenetic clocks weren't simply a Labrador phenomenon. Read the researchAbout Pet Food Australia: Pet Food Australia is an Australian-owned pet nutrition company focused on developing high-quality dog food and innovative pet health products.