At What Age Is a Puppy Considered an Adult?

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Puppies go through a series of seven developmental stages on their path to adulthood. Each is important and challenging for its own reasons. Your puppy becomes an adult as soon as he reaches the seventh and final stage of growth. There is no specific time frame that applies to all dogs. Instead development times depend entirely on your dog's breed and size, and may even vary with pups from the same litter. Just as with personality, no two dogs are exactly the same when it comes to growing up.


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Early Puppyhood

The first two stages of a puppy's life are critical in terms of his overall health and well-being. The first stage, which occurs at birth to 3 weeks, leaves your puppy quite vulnerable as his eyes are closed, his ears shut and his teeth not quite grown in. The second phase occurs at 3 to 7 weeks, and is where your puppy will begin eliminating away from the litter, poking around his area and learning some basic manners for interacting with both humans and other dogs.

Exploration and Socialization


The next two phases find your puppy exploring his surroundings and learning lessons about the world he inhabits. From 7 to 12 weeks, the puppy will be open to new encounters and new experiences; this a perfect time to start building some of those good habits through a group training class. It is also during this stage that a puppy's socialization becomes critical -- you must expose your dog to as many positive experiences with other people and dogs as possible to make sure he is adequately socialized. The next phase, at 12 to 17 weeks, usually brings a mixture of behaviors between curious dog and nervous puppy. Your puppy is transitioning into the toughest phase of all: adolescence.



Adolescent dogs are often as frustrating as teenage humans. The fifth development stage, which happens from 17 to 40 weeks, is marked by limit-testing, rule-breaking and other frustrating behaviors. Keep your habits in place during this period, as consistency is the most important factor in raising amazing, well-behaved dogs. The sixth phase occurs around 40 to 52 weeks and brings more teenage behavior, but hints of sexual maturity. Stick to your established habits and you'll come through this phase unscathed.



The amount of time it takes for a dog to reach the final development phase of adulthood depends greatly on the specific animal. Smaller dogs are done growing and maturing near the end of the first year, while larger dogs may still have another year to go. Giant breeds can take much longer to reach adulthood -- something to consider when selecting a new puppy. Generally speaking, small dogs hit adulthood in about a year, big dogs in two and huge dogs in three. If you're curious about your breed's specific growth patterns, speak with your vet.

By Todd Bowerman



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About the Author
Based primarily in Austin, Texas, Todd Bowerman has been working as a writer since 2004. He has provided numerous independent clients with ghostwriting and SEO copywriting services. Bowerman currently serves as editor-in-chief of Button Masher Online. He studied English at DePaul University.