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If dog lovers were asked about a dog's life cycle, they would say that it's too short!

 From the rambunctious days of puppy hood, to the slowing down process associated with aging, dogs surely cycle through these life stages quickly, filling our lives with much joy as we adapt to the changes from one stage of the dog's life to another.

 Sharing our lives with our dogs is ultimately an important lesson as dogs teach us about valuing life and the importance of cherishing every happy moment it brings.

 Discovering more about a dog's life cycle therefore, brings us closer to understanding our marvelous animals and knowing what to expect so that we can be one step ahead of the game.

mother dog

1) Puppies Go Through Developmental Stages...

A dog's life cycle starts from the day he or she is born. 

When you picked up your adorable puppy from your breeder, shelter or pet store at 8 weeks old, you missed out several developmental stages the puppy has gone through. No worries! We will briefly outline some of the most important milestones for you.

Please note though that these development stages aren't clear cut as each puppy develops at a different rate, and there may also be some overlapping between one stage and another. According to John Paul Scott and John Fuller's studies on puppy development, the stages can be divided in 3 categories:

1. Neonatal stage (birth - 2 weeks). Born deaf, blind and unable to stay warm, puppies are in a pretty much helpless state. During the pup's first two weeks of life though he goes through quite some rapid changes.

2. Transitional stage (2-3 weeks). During this stage, puppies start seeing and hearing. With their eyes open and their ability to stand and walk around a little, puppies start exploring the world.

3. Socialization stage (3-13 weeks) With their senses developed, puppies are now learning more about their surroundings. This is the prime time when they should be introduced to pets and other people. While the breeder starts socialization in the home, it's then up to the new dog owner to expand the pup's socialization while still keeping the pup safe from infectious diseases. Puppies play a whole lot during this time and learn more about being a dog. Around 11 weeks (but there are variances), puppies may go through a fear period too.

"Scientists divide development into separate stages largely for descriptive convenience. However, development is a continual and dynamic process: Dogs do not abruptly leave one stage and enter another, rather the progression is smooth and the stages overlap considerably."~ Ian Dunbar

2) And They Go Through a Teenager Phase Too!

dog pawing eyes

Think the teenager phase only happens in humans? Think again; puppies go through doggy adolescence too! Sure, you won't find Rover wearing headphones, drinking soda or chewing gum, but you may notice several changes both physically and mentally.

When do dogs hit this stage? Generally, the adolescent stage in dogs starts anywhere between the ages of 4 and 6 months. While all dogs go through the adolescent stage, in some dogs it may be barely noticeable, while in others, dog owners may pulling out their hair.

This is when Sadie gets goes by her second name "stubborn" and Rover's second name becomes "rowdy." You may notice your dog being more distracted, reluctant to pay attention and more likely to engage in undesirable behaviors (ie rowdy jumping, digging, barking etc)

Doggy adolescence is a temporary time of passage during which developing dogs start looking more and more like adult dogs, but their brain can still retain certain behaviors that may be puppy-like. Governed by powerful hormones, the dog's body starts developing, with female dogs (those not spayed) going into heat and male dogs become more interested in urine marking, roaming and sniffing around.

Fortunately, adolescence in dogs doesn't last forever, even though in larger dogs it tends to linger for a longer period of time. Generally, expect adolescence in small to medium dogs to last until the dog reaches 18 and 24 months, whereas, in large and giant dogs it may last even until 36 months (yup, until they're 3 years old!) Fortunately, training (and possibly behavior modification) using gentle, yet consistent methods (with the help of a trainer/behavior consultant) can help nip problems in the bud before they become established.

"As with humans, an animal's juvenile and adolescent periods have a profound impact on the animal's behavior. This is the most trying time when raising a pet, and a time when most owners reach the limits of their knowledge and fall short of their obligations as a responsible pet owner."~ Lore I. Haug

3) Adulthood Brings Stability....

dog paw

Once dogs are past doggy adolescence, they will reach adulthood. When adulthood starts once again depends on your dog's breed. Generally, adulthood in dogs may start at 18 months for the smaller breeds and 3 years of age for the large ones.

Many people find that their dogs at this point of their life-cycle are much easier to manage. With a full house-trained dog and the hyper puppy years just behind, adulthood brings the benefit of dogs who are generally calmer and less demanding.

Adulthood can be a nice smooth ride and dog owners enjoy the perk. Many dog owners report their dogs turning into "pure gold" once they reach age 5.

Sure, adult dogs will still enjoy exercise and mental stimulation, but generally they are less likely to be bouncing of the walls as they used to in the younger years. Dog owners who have invested their time wisely in socializing their dogs and getting them trained, are now rewarded with an obedient dog. Training though does not end now! Dogs thrive on being kept mentally stimulated and need a job, so this is a great time to enroll an adult dog in advanced obedience or perhaps some fun doggy sports.

4) While the Golden Years Bring Wisdom

dog-guarding-home old

Depending on your dog's breed, he will reach his golden years anywhere in between 7 and 10 years.

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When dogs get old, you may notice a grey hair here and there on their muzzles and they may slow down a bit. They may prefer a calm stroll on a quiet path at a comfortably lazy pace in place of the brisk games of fetch or hide 'n seek of his younger years.

In large dogs, joint pain may start developing as arthritis sets in, while smaller dogs may be prone to back and neck problems.

 Dental problems are not unusual considering the many years of tartar accumulating. You may also find that your older dog tends to sleep more than before and he may not need to eat as much as he used to.

Keeping up with regular vet visits is important at this point of the dog's life cycle. The earlier problems are caught, generally the better the outcome.

5) The One Dog Year Equals Seven Human Years Turned Out Being a Myth....

You may have heard that you can easily convert your dog's years into human years by simply multiplying your dog's age by seven, but turns out, this simple calculation is inaccurate.

For sake of an example, let's imagine that Bella, the saucy Pomeranian next door, is one year old. If you multiply her age by seven, then that would mean that she would be the equivalent of a 7-year old child. OK, so what's wrong with that?

Problem is, that, at the age of seven, a child is likely still playing with her Barbie dolls, while Bella is mature enough to give birth to a litter of puppies! --Not saying that Bella should be bred, just that Mother Nature would have prepared her for reproductive success by this age.

On top of dogs maturing faster than people, there's also the breed factor. Dogs come in many different shapes and sizes, and therefore dogs undergo different life cycles compared to one another.

Nowadays, there are more accurate ways to tell how many years a dog is compared to a humans'. For instance, there are several handy dog age calculators that are based on individual factors such as a dog's breed. 

With the size factor kept into consideration, it is therefore more likely to get a better idea of how much a dog year equals in human years. While no calculator is totally accurate, they do a much better job than the old 'one dog year equals seven humans years' belief.

Did you know? Lately, new research in the Cell Systems journal  has revealed a more accurate formula to calculate a dog's age, and this time it's based on chemical changes in the DNA as dogs grow old.

6) But the Fact that Large Dogs Age Faster is True.


Actually, more than a matter of size or breed, longevity in dogs seems to be a matter of weight.

 Generally, statistics show us that dogs weighing under 30 pounds are the ones blessed with longer lifespans. 

However, since dog breeds come in average weights, one can roughly deduce a dog's life expectancy by considering breed.

For instance, according to the UC Davis "Book of Dogs," a small-breed dog such as a small terrier is considered geriatric at about 11 years; while a medium-breed dog (think larger spaniels) becomes senior at 10 years.

When it comes to large-breed dogs such as German Shepherd dogs, they becomes seniors at 8 years while 7 years is considered already a geriatric age for giant-breed dogs such as great danes.

Of course, there are other factors to consider as well such as the dog's diet, overall health, his lifestyle, not to mention the role of genetics. And as in people, sex also seems to play a role, considering that generally female dogs seem to live just a bit longer than male dogs. 

And when it comes to dog owners who elect to have snip-snip surgeries on their dogs, they are rewarded with more time with their pals considering that Science Daily tells us that spayed or neutered dogs live longer.

How long a dog lives is therefore ultimately a matter of genetic potential. Every animal is gifted with a certain predetermined average lifespan. For instance, an elephant may live up to 70, whereas a giant tortoise can live a whole century. 

Dogs compared to humans weren't really gifted with a long lifespan, considering that the average dog lives to be 13, but as much as this is saddening, we can at least feel better considering that a mouse barely makes it to 5!

Did you know? Scientists at the University of Washington are conducting research in hopes of unlocking the secrets for a longer lifespan in dogs. The field of study addressing the biology of aging is called "geroscience" and you can learn more about it at  The Dog Aging Project website.


  • Siegal, Mordecai (Ed.; 1995). UC Davis School of Veterinary Medicine Book of the Dogs; Chapter 5, "Geriatrics", by Aldrich, Janet. Harper Collins.
  • University of Georgia. "Spayed or neutered dogs live longer." ScienceDaily. ScienceDaily, 17 April 2013
  • Dog Star Daily, Puppy Personality Development, retrieved from the web on November 25th, 2016

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