Sometime after your dog reaches 6 months, he or she will plunge headlong into canine adolescence – where hormones rule. He tears through the house, leaving a mess in his wake. She's suddenly shy and her happy personality has dissolved into moodiness. Like people, dogs react differently to puberty. Some have an easier time of it than others, but a "teenage dog" of any breed can display unpredictable, even uncharacteristic behavior – which can last an entire year. Behavior seems to depend more on the individual dog than on the breed.
The following list will help you know what to expect from your puppy
as he develops. How Big? Most small to medium sized 9-month-old dogs are approximately 80 % of their adult size. Larger breed dogs may mature later.
Teething - 9-month-old dogs will have all of their permanent teeth, which include 42 teeth. Take care of them with daily brushing.
Senses - By 9 months of age, most dogs have a very keen sense of hearing, vision, taste and smell. Most dogs can differentiate one dog (and human) smell from another.
Ability to Hold Urine – 9-month-old puppies can generally hold their urine for about 7 to 8 hours. This means you will need to take them out at least every 7 hours if you expect them to not have an accident.
Intelligence – 9-month-old puppies are peak in their adolescence stage. They are smart, curious, strong, willful, and very playful. They may take more risks by eating things that younger puppies may not. They also have more energy and are awake more so it is important to provide them with plenty of opportunities to play and exercise. It's easy to get into the practice of endlessly telling your dog "no" when you observe unwanted behaviors. But it's not a good pattern to adopt. Instead, distract the dog from learning the unwanted behavior in the first place by providing enough toys, trips to new places and other stimulation. That is, teach your dog what you want him to do, not simply what not to do.
Agility – Most puppies that are 9 months old very strong and coordinated with at least 80% of their adult coordination and development. They can play with excellent accuracy. Your teen-age dog will benefit and learn from distractions - exercise, play, toys, and the company of other dogs. If you alone can't keep up with his high energy level, arrange for him to frolic in a dog park with other canine teens.
Sleep – Puppies that are 9 months old sleep approximately 15 to 18 hours per day. The rest is spent eating, playing and eliminating.
Physical Appearance & Hair Coat - Around this time, your puppy will go through an intense period of shedding his fuzzy puppy coat and acquiring the type of hair distinctive to his breed. Be prepared to brush him and vacuum your home often. His physical appearance will be much more like an adult than the puppy he was.
Puberty - Puberty has set in and unplanned pregnancies are possible, so be ready to take precautions or consider spaying or neutering if this has not already been done. The onset of puberty will be most recognizable in your male dog. He'll begin lifting his leg to mark territory and mounting other dogs, humans, and even furniture. A non-spayed female experiences her first heat around 6 to 8 months of age. A neutered male reaches sexual maturity at about the same time. Spaying or neutering before seven months evens out the vicissitudes of youth somewhat, but you can't avoid them altogether. It's not unusual to discover a puddle of urine, left by a formerly housebroken adolescent dog. Females use urine to attract mates; males use it to mark their territory. In adolescence, such tendencies may remain even though your pet is "fixed."
Tips on Best Ways to Raise Your 9-month-old Old Puppy
Consider that crate training is for life
Take him out at least every 7 hours
Brush teeth daily
Feed twice daily
Make sure he gets plenty of exercise!
Switch out safe chew toys
Give positive reinforcement for work well done
Don't let your puppy chew on anything he can swallow
Brace yourself for dealing with the many moods of adolescence
If your teenager frequently becomes submissive, don't scold her
Kneel down on her level and praise her when she responds positively
If he becomes aggressive, frightened, or anxious, don't rush to calm or comfort him, because that reinforces the behavior, by giving him the attention he wants
Read about What your 9-month-old Puppy Needs to Stay Healthy!