Nearly every puppy will shed his undercoat at some point in the first year of his life. With a little preparation and planning, you can ensure that you and your puppy make it through the process with ease and as little vacuum-clogging as possible.
Puppy Coat Shedding
It is very likely that sometime between the age of 6 months and a year old, many puppies will start to shed their undercoat. This can be a messy process that can last as little as a week and as long as a month. This process can be an easy one if you are prepared with reasonable expectations and a little patience.
Some breeds like Siberian huskies and Great Pyrenees have very thick undercoats, so if your puppy is a breed with a think undercoat, be prepared. Two times a year, in the spring and fall, your puppy will lose the majority of this thick undercoat in a process called "blowing" her coat. If your puppy's coat is not brushed frequently and kept well-groomed, this could lead to a big mess in your house. For a breed with a heavy undercoat, it is even more important for you to prepare your puppy by desensitizing him to brushes and grooming tools. This way your puppy blowing his undercoat doesn't have to be a battle of wills or cause of anxiety.
Dealing with Shedding
There are a few things you can do for your puppy to help make the process of shedding his undercoat easier. As early as possible, condition your puppy to enjoy brushing with a brush that is appropriate for his coat type. Frequent treats and positive reinforcement will go a long way toward helping your puppy see grooming time as a fun adventure instead of a stressful event. Once your puppy has been properly conditioned to enjoy grooming, make sure you bathe him the proper amount for his breed and skin type.
Know Your Dog's Cycle
Unless your dog blows his undercoat, in which case you will only have to deal with major shedding twice a year, your pup will probably shed on a fairly regular schedule. Many breeds go through periods of shedding every six to eight weeks, so you can mark it on your calendar and be aware of when a shedding cycle is approaching. During that time plan to spend extra time brushing and grooming and make sure your pup's coat is kept well trimmed before it starts to fall out in bulk.