Remember being told that you can convert your dog’s age into human years by multiplying the former by 7?
Well, the latest research published in the Cell Systems magazine tells us that it’s not as straight forward and our dogs may, in fact, be older in human years than we previously thought…
This time the scientists took blood samples from 104 labs spanning a 16-year age range to follow the changes that occur within the dog’s DNA sequences over lifetime. They then compared them to 320 human samples taken from people aged between birth and 103.
The aim of the study wasn’t simply finding out the most perfect age conversion. Instead, the researched wanted to compare the changes that occur in dogs’ and humans’ genes as we age, see how these changes can be utilised to improve the quality of life, and learn whether or not “the methylome* can be used to quantitatively translate the age-related physiology experienced by one organism (i.e., a model species like dog) to the age at which physiology in a second organism is most similar (i.e., a second model or humans)”.
These changes tend to occur at certain milestones of our lives showing as new attachments of the DNA structure (called DNA methylation), thus allowing the researches to use the DNA and these alterations (also referred to as the “epigenetic clock”) as a reliable estimate of a person’s age.
The dogs were chosen for the study because they are the species we tend to share our lives, diet, chemical exposure and environment more than any other animals.
The highest similarities in sequence changes were noted in young dogs and young adults, as well as senior dogs and older people. The results of the analysis also showed that an 8-week old puppy is likely to be equal to a 9-month old baby, will be similar to a 31-year old by the time he turns one, and the 12-year old lab can be compared to a 70-year old adult. The adolescent stage was less predictable, possibly due to the fact that dogs have a shorter lifespan.
For me, another fascinating discovery was the dramatic age jump during the first year of dog’s life (from birth to being 31!) yet how the process slowed down once the dog celebrated his third birthday.
The geneticists did come with an algorithm for calculating the age, which was a bit more challenging than multiplying our dog’s age by 7.
human_age = 16 ln(dog_age) + 31
If you fancy doing it yourself, you first need to multiply your dog’s natural logarithm by 16, then add 31.
However, I did the maths for you to keep things simple…
Dog’s age = 1 years old / Human age = 31 years old
Dog’s age = 2 years old / Human age = 42.1 years old
Dog’s age = 3 years old / Human age = 48.6 years old
Dog’s age = 4 years old / Human age = 53.2 years old
Dog’s age = 5 years old / Human age = 56.8 years old
Dog’s age = 6 years old / Human age = 59.7 years old
Dog’s age = 7 years old / Human age = 62.1 years old
Dog’s age = 8 years old / Human age = 64.3 years old
Dog’s age = 9 years old / Human age = 66.2 years old
Dog’s age = 10 years old / Human age = 67.8 years old
Dog’s age = 11 years old / Human age = 69.4 years old
Dog’s age = 12 years old / Human age = 70.8 years old
Dog’s age = 13 years old / Human age = 72 years old
Dog’s age = 14 years old / Human age = 73.2 years old
Dog’s age = 15 years old / Human age = 74.3 years old
Dog’s age = 16 years old / Human age = 75.4 years old
So how old is your cocker in human years? I am still struggling to process the fact that Coop is already over 50 and my little Fred is same age as me, if not a bit older. Quite a shock to the system, mainly mine, of course.
* the activity within the DNA that changes during our lifetime