Emma scott 
Most pups join their new homes around 8-12 weeks, leaving behind their mothers, littermates, and infancy. This developmental period is called the impression phase while the brain is rapidly developing, and the dog is dominant and ideal for training.
The puppy picks up on its good and bad behavior patterns from its experiences and environment during this critical learning period. It’s essential to look at a puppy’s physical and behavioral milestones and health and nutrition during this crucial puppy stage.
Physical Development
An 8-12-week old puppy will still be relatively small, even though the puppy is a large breed of dog. Puppies are physically weak and a bit clumsy. They require a lot of supervision and cratering when alone.
Note: Expect your puppy to sleep a lot during this phase, up to 18 to 20 hours a day, to support his rapidly growing mind and body.
Read- caring for a Newborn Puppy – Newborn to One Week Old
An 8-12-week old puppy House Training
Before 12 weeks of puppy age, most puppies will have trouble controlling their urination and defecation. They are often prone to accidents and cannot make it through the night without urinating.
House training should begin soon, but be prepared to go slowly for the first few weeks. Stick to a regular schedule, taking your pup outside every time they eat, drink, or nap. Take your puppy dog to a designated “potty spot.” After a few weeks, she’ll learn to have better control over her bodily functions.
Teething
Depending on the dog breed, your puppy won’t start getting adult teeth until around 16 weeks of age. Some of its puppy baby teeth or “milk teeth” may fall out between 8 and 12 weeks. The symptoms of teething usually won’t start until 12 weeks of age. You know your dog’s teeth are falling out when you notice excessive salivation, excessive chewing, paw in the mouth, and bloody residue on chewed objects.
An 8-12-week old puppy Behavioral Changes
The period from 3 weeks to 12 weeks is an important socialization period. 1 This time is often called the “fear phase” because puppies are afraid of everything—practice handling your puppy so that he gets used to being held and touched in unfamiliar ways.
Expect your young doggy to react with fear in certain situations, but avoid petting or comforting the timid puppy. Find ways to introduce new sounds, sights, and environments such as vet visits, baths, and nail trims, and keep everything positive.
Reward your puppy friend for relaxing in new situations and exploring new things. However, please don’t force your puppy to accept a position that frightens him. Nothing to worry about if you stay upbeat and calm. Act as if the situation is regular.
Read- From 1 To 8 Weeks Newborn Puppies Care Plan
Health and Care
Between 6 and 8 weeks of puppy age, your puppy will need to go to the vet for their first puppy vaccines, deworming, and an exam. 2 The breeder or adoption group will have administered their first vaccines, and deworming the puppy will be taken to the vet.
Regardless, it would help if you took your new puppy to your vet within a few days to make sure it is in good health. Bring any records provided by the adoption group or the breeder so your vet can adjust or determine the vaccination schedule.
Disease Prevention
By 18 weeks of puppy age, the puppy should have had all of its vaccines. But till then, you need to avoid coming in contact with diseases. Do not allow your puppy to walk or interact with unfamiliar animals in public areas. Your pup can play with healthy puppies and vaccinated and worm-free adult dogs. Make sure you know the other dog’s owner and trust that the dog is healthy.
An 8-12-week old puppy Food and Nutrition
Puppies begin weaning from their mother’s milk at around 3 to 6 weeks and are usually entirely weaned between 6 and 8 weeks. By the time you get a new puppy, he should already eat puppy food for at least a few weeks. The breeder or adopter should let you know what type of food he is eating.
Puppy Food
If possible, start with the same diet. Allow your new puppy dog to adjust to its environment for days or weeks before choosing fresh food. If you decide to change a meal, gradually transition to the new food to avoid causing gastrointestinal upset.
Your dog needs proper nutrition to thrive and grow. Provide high-quality puppy food labeled for growth. Most puppies between 8 and 12 weeks should be fed three times a day, some evenly spaced. This regularity in meal times helps prevent blood sugar drops, especially in small breeds.
How Much Should You Feed a Puppy?
Begin by feeding the amount of food recommended on the packaging for your puppy’s weight. Check your pup’s weight every few days to see if the amount of food needs to be adjusted. If your puppy seems greedy and is not gaining weight, adjust by adding more food.
If the gift is left far behind, reduce it. At your vet visit, discuss the type of food you are feeding, the frequency of feedings, and the amount you provide daily versus consumed. Ask your vet if you need to make any dietary adjustments.
Homemade Dog Food
If you want to feed homemade dog food, you can, but you must carefully, as a poorly prepared diet can be dangerous. Consult with your vet about the prescription you plan to use. You’ll need to make sure it’s a balanced, nutritious recipe, using the right ingredients and calories.
There are a variety of treats your puppy can have as long as they are safe, healthy, non-toxic, and make up no more than about 10 percent of your puppy’s daily caloric intake.
An 8-12-week old puppy Training
Even though your puppy is still a toddler, starting training when he comes home with you is essential. Start simple. Teach your puppy his name. You should give the dog a few days to get used to the rules of the house, such as where it is allowed to go and where are the prohibited areas in the home.
Let it get used to the feel of the collar before adding the leash. Then, you can begin to let the dog pull the leash so that it senses its feeling. As soon as the pup is comfortable with this, you can train him to walk on a leash.
Although this is a rapid learning period, your puppy may not be the fastest learner at first as many “firsts,” new scents, places, and people all start to come to mind. You can also begin by offering basic commands like sit, stay, and down. Go slow, be patient, stay positive and have fun.