Picking out a canine friend to join your family can be a fun experience. Sometimes a particular puppy is chosen based on looks alone. Maybe they have a cute heart-shaped patch on their head or potential for the show circuit. But most puppies are chosen because their personality seems favorable to their future owner. However, your dog's behavior will change throughout life, so their character will be different once they mature.
Young dogs are more active
Puppies generally like to roughhouse with one another, but some are much more active than others. After you take your pup home, you'll discover their activity level is usually in "sleep mode" for much of the day as long as they're not filling their round bellies or relieving themselves. By the time dogs are six months to a year old, they'll be at their most active, which means it's crucial to keep them exercised and occupied, so they don't destroy your furniture for entertainment.
Mike Linnane / 500px/ Getty Images
Juvenile dogs have the shortest memory
Forgetfulness is often associated with old age, but dogs younger than 24 months have shorter memory spans than seniors. This can be linked to the tremendous development their brains and bodies are undergoing. Your pup might forget where they put that toy they were just gnawing on or that the couch isn't meant for chewing. Be patient, as your dog will get their mental ducks in a row between six months and two years.
smrm1977/ Getty Images
Maturing dogs get more discerning with their trust
Most puppies are fairly trusting of anyone and will follow you diligently. However, as your dog matures and gets life experience, they'll likely become more cautious around other humans. Dogs who were abused in the first years of life often have trust issues. Fortunately, most can learn to trust again when placed in a secure home.
Image Source/ Getty Images
They get less excitable with age
Is your pup always on such high alert that they're barking at someone while they're still at the end of the driveway? There's good news. Your dog will calm down. Your dog's brain becomes fully developed by the time they're two years old, and hormones make them alert to potential mates or possible intruders in their territory. This is why spaying (or neutering) your dog can help them relax as they would be without hormones running rampant. Your dog's excitability level will decrease steadily as they get whether they're neutered or intact.
Justin Paget/ Getty Images
Dogs peak in attentiveness in early adulthood
Your young dog likely runs after squirrels and other distractions. Dogs are most trainable in the early adult phase of life bout one to three years old) when they're most attentive. (That doesn't mean you shouldn't train your pup; rather, just keep sessions short and frequent.) As your dog gets older, their attentiveness will also decline. Instead of running after the nearest squirrel, they'll often just close their eyes to take a snooze.
Nico De Pasquale Photography/ Getty Images
Your dog's aggressiveness peaks at about four years
Your dog's age has a lot to do with how bold or aggressive they are. Aggression peaks in mature adulthood and declines once a dog achieves "senior status" at five years. Dogs who are intact are bolder than those who are spayed or neutered, and males are typically more aggressive than females.
Liudmila Chernetska/ Getty Images
Breeds with shorter lives have fewer personality changes
Great Danes and other breeds with the shortest average lifespans show the least amount of behavioral changes over their lives. These short-lived breeds don't experience noticeable cognitive or behavioral aging until they die as mature adults at seven to ten years old. You'll likely enjoy your dog acting as though they're in their prime right up to the end, but it can be shocking to lose your dog suddenly when there was little to indicate that the end was near.
Christopher Bernard/ Getty Images
Your dog might experience cognitive decline
At about ten years old, long-lived dogs start to decline mentally. This cognitive decline usually begins gradually, but at about 15 years old, it usually increases dramatically. Your dog might start wandering the house as if forgetting how to find their way around or suddenly start relieving themselves indoors. A trip to the vet can determine whether behaviors are due to disease or cognitive decline.
alexsokolov/ Getty Images
Dramatic behavior changes in the first and last years of their life
Your dog's behavior will change the most during the first two years of their life when their brain is still developing. Behavior changes at their life's end depending on the breed. Some dogs need geriatric care at age five or six, while other breeds won't decline until they're 15.
Capuski/ Getty Images
You can predict your
You can anticipate your dog's mental changes by understanding the behavioral tendencies of each of the four stages of a dog's life (juvenile, mature adult, senior adult, and geriatric). Should your dog take an unexpected shift in behavior, they could be experiencing pain or illness, so visit your vet to check for health problems.