Scientists have developed a new method for calculating how old a dog is in human years, and they say it’s more accurate than the old way, NPR reports.
The traditional formula is to multiply the dog’s years by seven. But the researchers involved in this study say dog’s age rapidly at first and much more slowly in later years.
The new method is based on an epigenetic marker called methylation. The study, published here, involved drawing blood from more than 100 Labrador retrievers ranging in age from 4 weeks to 16 years.
Based on the new method, dog ages break down like this:
- Juvenile: 2 to 6 months in dogs, equivalent to 1 to 12 years in humans.
- Adolescent: 6 months to 2 years in dogs, equivalent to 12 to 25 years in humans.
- Mature: 2 to 7 years in dogs, equivalent to 25 to 50 years in humans.
- Senior: 12 years and up in dogs, equivalent to 70 years and up in humans.
A calculator based on the researched was published here. Smithsonianmag.com explains that the formula involves multiplying the natural logarithm of a dog’s age by 16, then adding 31 [human_age = 16ln(dog_age) + 31].
By the formula, a 2-year-old dog is equivalent to a 42-year-old human. An 8-year-old dog equal to a 64-year-old human.
Read more at NPR