Your puppy will likely have bouts of naughtiness throughout their first year, but after 12 months of age, your puppy will calm down.
The most challenging time of raising a puppy is the adolescent period. Dogs become “teenagers” and seem to forget everything they have ever been taught. This period is individual to each dog, but it may begin when he's about eight months old and continue until he's two years old.
As dogs get older, their social circles shrink. They enter sexual maturity around 7-9 months and social maturity at 1-3 years. With that maturity and wisdom, they may be less interested in playing or they might play more roughly when excited. That rough play may lead to aggressive habits.
The age of onset of dominance-related aggression is most commonly thought to be at social maturity around two years of age. However, it has been described in very young dogs (i.e. five months) and can also occur in older dogs.
Generally, puppies start to calm down when they reach emotional maturity — around 1 year old.
Health issues that can change your dog's behavior include arthritis, hip dysplasia, luxating patellas, sore teeth, thyroid problems, epilepsy/seizures, ear infections, digestive issues, skin or environmental allergies, yeast infections, hearing loss, eyesight loss, and cancer.
In many cases, the issue is that the dog has not learned what you want him to do instead (see Greeting Behavior – Jumping Up, Enrichment, Predictability, and Scheduling, and Training Basics). Attempting to reprimand all the misbehavior will be ineffective.
OK—this one isn't necessarily your fault, but the way you respond to it can make a difference in your dog's behavior. Like humans, dogs go through a rebellious “teenager” phase (around 5 months to 18 months).
Let's face it: Bad behavior gets attention, even though it's not typically positive attention. But sometimes ignoring bad behavior is the best way to get it to stop. Believe it or not, giving your dog the cold shoulder when he does something he shouldn't, can be the first step to solving a behavior problem.
When done correctly and when combined with proactive training, ignoring unwanted behavior can work. However, the time it takes depends on your dog's reinforcement history and their own personal enjoyment of the behavior. For some dogs, they get through an extinction burst quickly, while others can take quite a while.
If an otherwise non-aggressive dog suddenly turns aggressive, it's possible that they might be sick or in pain. Dogs that are hurting will even snap, growl, or bark at their owners. Take your dog to a vet to see if there's a health issue.
Behavior changes in dogs can be challenging, which is why we say to nip unwanted behaviors in the bud as soon as possible. It takes a long time to instigate change when that behavior has been there for a long time. If the problem has been there for three weeks, it can take you three weeks to correct.
Yelling encourages bad behavior
That shows your dog she has no incentive to come back. Instead, call your dog and when she comes back, praise her and give her a treat. If all you do is yell, why would your dog want to please you?
"And while they become less oriented to problem-solving and novelty-seeking as they get older, they remain obedient and social, which is probably the most important thing for owners."
Most dogs assume a neutral or submissive role toward people, but some dogs will challenge their owners for dominance. A dominant dog may stare, bark, growl, snap, or even bite when you give him a command or ask him to give up a toy, treat, or resting place.
By about two years of age, many dogs have reached the full extent of whatever aggression they have in them, and there may be a dogfight or biting incident around this time.
Breaking Eye Contact
In the wild, alphas put betas and omegas in their place with a decisive stare. If your dog breaks eye contact with you first, this is a dramatic sign of them viewing you as the alpha. It also demonstrates that you can discipline your dog with nothing more than a look.
By about two years of age, many dogs have reached the full extent of whatever aggression they have in them, and there may be a dogfight or biting incident around this time.
Health issues that can change your dog's behavior include arthritis, hip dysplasia, luxating patellas, sore teeth, thyroid problems, epilepsy/seizures, ear infections, digestive issues, skin or environmental allergies, yeast infections, hearing loss, eyesight loss, and cancer.
[4] A dog's personality is mostly shaped in the first four-months of the puppy's life and this will have a pronounced impact on the puppy that will last a lifetime. After the first 16-weeks it not realistic to think we will change the dog's temperament (pre-disposition).
"Dogs that are active and curious when young will remain active and curious when they get old, but only compared to other dogs. A dog's personality changes over time, and, on average, every dog becomes less active and less curious as they age."