Age of the dog : how to calculate it ?
Considered since the dawn of time as man’s best friend, the dog also has another characteristic: he has two kinds of age! First, his biological age, which is the number of years that have actually passed since his birth. But sometimes, you have no way of knowing the date of birth of your doggie. Unfortunately, animals found or adopted as adults do not carry their identity card with them, so we are reduced to calculating their biological age according to certain criteria. Which ones? How can I calculate my dog’s age if I have no idea when he was born?
But the dog also has a human age which corresponds to the equivalence of its biological age in human years. It is a conversion of his biological age into human age! As everyone knows, at 15 years old, a dog is closer to an old man than to a teenager. So how old would he be if he were a man? How do I calculate my dog’s age on a human scale?
This dog guide will help you answer all these questions in order to know everything about the real age of dogs and puppies!
1- Why calculate the age of my dog ?
Many owners have fun calculating their dog’s age in its human equivalent. However, there are several advantages to determining the human age of a dog. First of all, why is it important to know your dog’s age? It’s fun to be able to assign a certain number of years to your dog, and even more fun to convert those years into “human” age… but what else?
1-1 The age of the dog, an essential information
Far from being a simple object of curiosity, your dog’s age is a fundamental piece of information that will allow you to take good care of your four-legged friend. Indeed, this biological age serves as a basis for his diet but also his health. Veterinarians base themselves exclusively on the biological age of the dog to follow the vaccination schedule for dogs for example.
As an owner, it is also useful to evaluate your dog’s shape in relation to his human age. This information will help you to better understand the stage of your pet’s life. You might think that a 12 year old dog is still young, but he is already a senior.
Therefore, calculating your dog’s biological age first, and then its human age, will allow you to know :
At what stage of its life the animal is.
What are its needs.
1-2 Why is my dog’s age important?
There are three main stages in a dog’s life: 1. youth (up to about two years old, depending on the breed), 2. adulthood and 3. old age (from 5 years old but sometimes not before 8 years old, depending on the breed). However, if an adult dog is in full possession of his strength and health, with little variation in his energy needs, a puppy as well as an older dog require special care. In particular, they need :
* A diet adapted to its age and thus to its needs.
* Vaccinations and deworming (for the puppy).
* Frequent health check-ups (for the older dog).
1-3 The period of senescence of a dog, what is it?
Knowing the age of your dog will allow you, in particular, to anticipate the beginning of its senescence period, i.e. its entry into old age. At this stage, the organic functions start to slow down, but in a very underground way. This is why, if you don’t know your dog’s age, you won’t notice right away that he is becoming an old man, and will be unable to take the necessary measures… that is to say, to start with, a complete check-up at the veterinarian!
By having your dog checked as soon as he enters old age, you will certainly avoid many health problems in the years to come, and will be able to gradually adapt his diet and exercise to the new constraints of his age.
In other words, knowing your dog’s age will ensure a peaceful retirement.
1-4 At what age will my dog be an old man?
There is no clearly defined age for all dogs, once and for all. Some dogs become “old” sooner than others. To know when your dog should be considered an old man, you need to know not only his age, but also his weight, according to the following chart:
* Less than 15 kilos: 10 years
* Between 15 and 40 kilos: 9 years
* More than 40 kilos: 7 years
* You have understood it: the bigger your dog is or belongs to a large breed, the earlier he will age… it’s the merciless law of nature!
2- How to know the biological age of your dog ?
Of course, if you bought your dog from a kennel, or if you know intimately the person who gave her to you and therefore the moment when the bitch gave birth, the question does not arise. The date of birth of the dog is a data present in its European passport. But if you have adopted an adult dog or picked up your dog in a shelter or on the street, it is very relevant!
When the puppy’s date of birth is unknown, fortunately you still have some physical characteristics, which careful observation will allow you, not to establish one hundred percent the biological age of the animal, but at least to get a precise idea.
To do so, focus on the eyes, the coat, the gait, the silhouette and, last but not least, the teeth of your doggie!
2-1 What do your dog’s eyes, coat, gait and body shape say about his age?
Observing your dog’s eyes, coat and gait will not allow you to know his age, but rather to situate him in one or the other of the 3 age brackets previously mentioned: youth, adulthood and old age.
* The eyes: in a young dog, they are bright and shiny. The older the animal gets, the more their brightness becomes dull, until they become almost opaque.
* The coat: soft and fine in the puppy, soft to the touch, it will become thicker and rougher as the dog grows. As the dog approaches the age of maturity, lighter patches may form on the muzzle.
* Gait: well-defined muscles and a lot of energy… a dog in the prime of life will have a dynamic and confident gait!
* Figure: unless he is overweight, your dog will have a tendency to become thinner with age. His silhouette will be less nervous, more emaciated.
2-2 Teeth, organs that know a lot
But if you want to give your dog a precise biological age, look at his teeth: their stage of development as well as their general condition will tell you as much, or almost as much, as a birth date written in black and white on a certificate!
In dogs, the milk teeth, then the permanent teeth, appear in the following order:
* Between 8 weeks and 6 months: the milk teeth (canines at 21 days, corner, middle and claw incisors at 25, 28 and 30 days, molars between the 3rd and 5th week).
* Between 4 and 7 months: the permanent teeth (claws at 4 months, middles at 4.5, corners at 5, canines at 6-7 months).
* Between 1 and 2 years of age: teeth start to yellow, tartar starts to accumulate. The lower central incisors, the first to be affected by wear, take on a slightly square shape.
* Between the ages of 3 and 5: the wear of the lower incisors is now visible, they become clearly square.
* Between 5 and 6 years: the upper incisors are affected by wear.
* After 6 years: tartar has accumulated, gums are sometimes red and swollen, teeth are missing… old age is near!
* According to the number of teeth that adorn your dog’s jaws, but also their shape and color, it will be possible for you (with the help of a veterinarian) to guess his biological age!
3- How to know the human age of your dog?
Now that you have established the biological age of your little four-legged friend, all you have to do is calculate his human age! To begin with, you should know that simply multiplying the real age by 7 is not reliable. You have to take into account several factors such as the breed of the dog and its size. Find out how to calculate the human age of your dog or use the online calculator to find out the human age of your dog.
3-1 Is there a magic number to calculate the human age of your dog?
For a long time, people thought that multiplying the biological age of their dog by 7 or 9 was enough to find out its human equivalent. Why?
In reality, the question of calculating the age of a dog is an old, very old story, which goes back to… Antiquity. Aristotle, in his History of Animals, already proposed some ideas concerning the longevity of species!
And in the 18th century, the naturalist Buffon took over, proposing a very personal method to calculate the age of dogs. The scientist established a ratio between the life expectancy of man and dog. Some men live up to 81 years, most dogs up to 9 years… Common factor, therefore, between the two species, human and canine: the number 9. To calculate the age of your dog, you just have to multiply its biological age by 9, and that’s it!
According to other scientists, on the other hand – but according to the same reasoning, only varying the age considered as the life expectancy of both dog and man – it is on the contrary the number 7 the common denominator between humans and canines, a belief that has followed us until the 21st century, or almost!
However, a certain Dr. Lebeau, a veterinarian by trade, had noted as early as 1953 that the growth of dogs is up to 20 times faster than that of humans during the first year of their existence, before slowing down in a minor proportion, which varies, moreover, according to the size of the animal.
And you guessed it, he was right! But since calculating your dog’s age is a little more complex than it seems at first, here are a few more explanations to help you see things more clearly.
3-2 What does my dog’s size say about his biological age?
Not only is a dog’s growth rate different from that of humans, but it also varies with the size of the animal. A small dog will age more or less quickly than a large dog. To calculate your dog’s human age, you must first determine what size category he belongs to.
3-3 The 4 size categories of dogs
The size of a dog does not correspond to its height in centimeters, but rather to its weight. There are 4 size categories:
** Less than 10 kilos: small dog (Chihuahua, poodle, Pekingese, Bichon …).
** 10-23 kilos : medium size dog (pugs, labradors, spaniels, spitz…).
** 24-40 kilos: large dog (German shepherds, braques, dalmatians, huskys, setters…).
** More than 40 kilos : giant dog (Saint Bernards, Newfoundland, Leonbergers…).
3-4 The growth of the dog until 2 years
What does the size of your dog tell you about his human age?
First of all, it gives you information about his growth rate! Indeed, we consider that a dog enters adulthood once its growth is completed, that is to say, according to its size:
** Around 1 year for a small dog (beagle, English cocker spaniel, cavalier king charles…).
** Around 18 months-2 years for a dog of average size (chow-chow, dalmatian, Belgian shepherd…).
** Around 2 years, 2 years and a half months for a large dog (leonberg, barzoï, Irish greyhound…).
** These data speak for themselves: at around 2 years of age, when human babies are just starting to walk and talk, dogs are already considered adults. In other words, your four-legged friend grows up much faster than you do… an element that must be taken into account when calculating his age since it is scientifically considered that a 2-year-old dog has the same organic maturity as a 24-year-old adult man!
3-5 The growth of the adult dog
Until they reach adulthood, all dogs, whatever their size, age at the same rate, but over a longer or shorter period of time: we must therefore consider that a small dog of 1 year old and a big dog of 18 months old, both of which have just reached adulthood, are in fact the same age!
In addition, although they take longer than small dogs to become adults, large dogs age much more quickly, i.e. they reach the senescence threshold earlier.
This is why small dogs may age faster than large dogs early in life, but they actually live longer! Thus, the life expectancy of a large dog can be up to 25% less than that of a small dog. This would be a question of hormones: indeed, the largest dogs would have a higher level of growth hormones than small dogs, which would lead them to age more quickly, but also, consequently, to be more exposed to age-related diseases.
For example, a large dog will already be considered old at 6 years old, while at the same age, a small dog will still be in full possession of its youth.
3-6 So how do you calculate your dog’s human age?
You now have all the tools you need to calculate your dog’s human age.
Determine when your dog will enter adulthood based on his size. Based on the above principle, the first two years (or the first 18 months) of a dog’s life are equivalent to 24 human years.
So, at the average age of 2, your dog is 24 years old. Then, each year that comes after that is equivalent, depending on its size, to :
* 4 years for a small dog
* 5 years for a medium dog
* 6 years for a large dog
* 7 for a giant
Let’s take the example of an average dog like a Pyrenean Shepherd, which reached its adult maturity at 2 years old and is now 10 years old (biological age). Each of the 8 years between 2 and 10 years is worth 5 years of human life. So, to know his age, you have to do the following calculation:
24 years (the dog’s age at 2 years) + (8 x 5) = 24 + 40 = 64
An average 10 year old dog will be 64 years old in human age. But, at the same age, a St. Bernard, which ages faster, will actually be… 80 years old (24 + (8 x 7) = 80!)
3-7 What does this mean for my dog’s life expectancy?
You now know that if you have a large breed dog, its life expectancy will be limited compared to that of a small breed dog.
On average, a dog’s life expectancy ranges from 8 to 15 years, depending on the size category to which it belongs. A Chihuahua can live up to 15 years, while a German Shepherd may not live beyond 8 years.
However, there are many other factors to consider when calculating the life expectancy of your dog:
* Its diet
* Its lifestyle
* Its environment
In addition, your dog’s breed can influence the size criterion, which has some exceptions.
In particular, a brachycephalic dog such as a bulldog may be considered a small dog since it generally weighs less than 10 kilos, but its life expectancy is only about 12 years. Indeed, its particular morphology exposes it to certain respiratory disorders which shorten its life expectancy compared to other small dogs.
Moreover, some owners, for lack of financial means, do not always go to the veterinarian, whether it is for a simple routine check-up (prevention is better than cure according to the adage) or for a visible health problem. In the same way, vaccinations are not always done, etc., which is detrimental to the dog’s life expectancy in the long run. It is from the youngest age of the animal that it is necessary to subscribe to a health insurance for dog in order to be able to take him in case of emergency in a veterinary clinic. You will then be reimbursed for the veterinary fees charged to treat your pet.