The best place to consider purchasing your pug puppy from is an actual Pug Breeder. Reputable pug breeders make it a point of giving their dogs only quality care. You can discuss with and confirm with the breeder that vaccinations and other preventive care measures have been taken and that puppy has kennel club registration papers. Kennel Club registration papers will certify that your new pug puppy is in fact a purebred pug, exactly what the breeder claims him to be. There are many Kennel Clubs but the two top clubs are ACA (American Canine Association) and AKC (American Kennel Club.) If you receive registration papers from any other kennel club you may be getting a "watered down" breed. This is not always the case but you should take precautions and inspect the pugs and their kennels thoroughly. These other pet registries have less stringent breeding requirements and can easily be fooled by the breeder. There have been cases where a Doberman Pincher was registered as a Pug without any questions asked.
You can find breeders through referrals from your friends and family. If they are happy with the puppy they have, many will happily recommend their breeder to you. The breeder may not carry the breed of puppy you are looking for, but they, in turn, can recommend the appropriate puppy breeder or a purebred rescue group looking for responsible owners.
The humane society shelters and cares for dogs and puppies that are waiting for you to give them a good home. Many unwanted pugs and pug puppies are dropped off by their owners at the humane society and/or animal rescue leagues. The reasons can range from the pug being simply unwanted to the pug owner's new landlord not allowing pets. Many times it's something as simple as the previous owner got sick and could no longer care for the animal properly, but otherwise the animal is healthy and was well cared for and loved prior being taken to the humane society. There can be many other reasons a Pug may end up in a humane society. Either way, the humane society has gotten a bad reputation as a place for unwell strays and difficult dogs. This is not always the case! Most pugs end up at humane societies because their owner simply didn't take their decision to have a pug seriously. Just make sure that you ask a lot of questions about any dog or puppy that you may be considering adopting.
In your puppy search, steer clear of pet shops, puppy mills and puppy factories. Pet shops are usually supplied by puppy factories and/or puppy mills. These breeders do it for the money and only the money and are not concerned about the pug's health or the advancement of the breed. In many cases, they are ignorant of any knowledge about the pugs that they breed.
With pet shops or side-of-the-road breeders, you may not know what you are getting and therefore can't head off disaster for your companion. This could spell doom for your puppy if he is predisposed to any life-threatening diseases. Veterinarians can perform preventive care on breeds that can suffer certain predisposed conditions. Puppy mills will continue to breed a dog that has been diagnosed with a genetic defect, a reputable breeder will not.
Knowing where to buy a pug puppy is as important as what breed of puppy to buy. Take advice from trusted friends about reputable breeders in your area or on the Internet. If in doubt, visit the humane society or dog rescue groups. They will be glad to help in your search for the perfect puppy companion.