The age of a dog in human age – A history of calculation

Before we address the topic of a dog’s age in human years and how to calculate it, let’s take a look at the evolution of a puppy. It says a lot about the speed at which a dog ages. The maturity of man’s best friend depends on its size and breed. The bigger the dog is as an adult, the less quickly it grows. Small dogs mature sooner.

Adulthood thus corresponds to the age at which a dog has fully grown. Sexual maturity occurs before this age. If you know the approximate age at which your dog is classed as an adult, you will have a better understanding of its behavioural changes. Be patient with your dog during its teenage years: just like for humans, this part of life is often somewhat hectic. Adapt your dog’s diet to its new needs by giving it adult dog food. Do not hesitate to ask your vet for advice if you are not sure when the right time to change from puppy food to adult food is.

Small dogs weighing up to 15 kg include the following breeds: Maltese, Chihuahua, Yorkshire, Pug, Cairn Terrier, Cavalier King Charles, Jack Russell Terrier, etc.

Medium-sized dogs weighing between 15 and 40 kg include the following breeds: Labrador Retriever, Australian Shepherd, Siberian Husky, Continental Bulldog, Boxer, Collie, etc.

Large dogs weighing over 40 kg include the following breeds: Kangal, Great Dane, Leonberger, Mastiff, St. Bernard, Newfoundland, etc.

The age of 2-year-old dogs, 3-year-old dogs or 10-year-old dogs in human years differs from one breed to another.

American researchers at a Californian university have used a new method to determine the age of a dog in human years. Although the explanation for this method, which is based on DNA methylation and the epigenetic clock, is very scientific, you don’t need to be a maths whizz to use it. You can find online calculators where all you need to do is enter your dog’s age to get a number long enough to serve as a logarithm. You then need to multiply this logarithm by 16 and add 31. The result is the age of your dog in human years. As the study was carried out on Labradors, it appears to be more applicable to dogs of a similar size. However, the idea is interesting and will certainly lead to further research in this area.

A dog’s senescence threshold also varies depending on its size. In small dogs, signs of ageing appear at around nine years old. For medium-sized dogs, the senescence threshold is reached at 8 years old. The age is 6 years old for large dogs. But don’t worry – if your dog is getting close to this age or has already past it, it doesn’t mean that they have reached the end of their life. They still have many years to spend by your side. In fact, this age is the age at which you notice certain signs of ageing in your faithful companion:

• Greying hair
• Thinner and less shiny coat
• Visual and hearing impairments
• Loss of appetite
• Lack of energy
• Breathlessness
• Longer periods of sleep

When a dog enters this stage of life, its owners must, of course, continue to look after its welfare. If your dog no longer wants to go on long walks, offer several short walks. They will be physically active, can meet dog friends and exercise their joints. Ask your vet to examine your dog once or twice a year to detect illnesses as early as possible. Your dog is less active so it is also time to change their diet and offer high-quality senior food. Make the transition gradually to avoid digestive problems such as diarrhoea.

The size of your dog also influences their life expectancy. On average, small dogs live longer than large dogs. As well as size, the breed of a dog can also influence its lifespan. Some breeds are more susceptible to disease than others. Finally, a dog’s lifestyle plays a role in its lifespan. Just as in humans, obesity tends to shorten the length of life. A healthy diet tailored to the dog’s age and energy requirements is therefore essential for a long life as a healthy dog. Another factor that lengthens the life expectancy of a senior is physical activity. Daily walks are good for dogs and… for their owners. Just as with humans, stress can cause physical problems and lead to a shorter life. So make sure that your dog grows up in a positive atmosphere and feels safe. You will enjoy many years of dog ownership with your faithful companion. Remember that one year for a dog is many years for a human.