Do you mind if your new four-legged family member puts a dent in your nest egg? Even if you pick a free, mixed-breed dog instead of paying for a purebred pup, your new dog will make some substantial demands on your wallet. Here's what you need to know.

Pet Supplies

Preparing to adopt a dog is a lot like preparing for the first day of school. Before you attended class you needed notebooks, textbooks, pens and a backpack.

Before you bring your pup home, you need bedding, a crate, food and water dishes, identification tags, a collar, a leash, grooming supplies and - most important - treats! You'll also want to stock about two weeks' worth of food. The cost of these basic supplies adds up.

You need to think ahead, too. A one-year supply of dog food can cost hundreds of dollars depending on what type of food you choose and how much your dog eats.

And if your dog is lucky enough to get a yard in the deal, he'll need a fence or a dog run so he can romp around safely, and a doghouse or igloo for shelter if he'll be spending much time outdoors.

Many landlords don't welcome pets, especially large dogs. If you rent and your landlord does allow pets, he will likely charge a one-time pet deposit. You're also financially liable for any property damages your dog might cause.

Veterinarian Visits

You've got the supplies. You've got the pooch. Your next stop: the veterinarian. Your pet will need regular examinations, vaccinations and dental care. And your veterinarian may run other tests if necessary to ensure your dog is in top form. These annual expenses can run into the hundreds of dollars.

And don't forget about fleas, ticks, heartworms and intestinal parasites. Keeping parasites from latching on to your dog is a lot easier and cheaper than treating them, and your veterinarian can provide medications to keep these nasties away. But you must use the preventive medications regularly for them to be most effective.

Another expense: neutering or spaying. Unless you plan to breed or show your dog, your veterinarian will recommend spaying or neutering your pet. Doing so reduces your pup's risk for many health complications, prevents unwanted pregnancies, and heads off some behavior problems. It's worth every penny.

The cost of treating a serious illness or accident can quickly stretch into the four digits. And dogs today live longer - many well past 12 years - and can experience the same age-related conditions aging humans do, including arthritis, deteriorating eyesight and hearing and digestive troubles.

Can you commit to paying for your dog's basic and medical needs for a decade or more? Are you able and willing to pay $1,000 or more if your pet needs you?

Obedience Training

One of the best things you can do for your dog is teach him good manners. While most dogs and their owners can learn what they need to in relatively affordable group classes, in some cases it's necessary to supplement this training with private instruction or even pet boarding school.

Depending on how much additional training your dog gets, you could pay $100 to $1,000 for this service. But you'll see the payback everyday - and enjoy the time you spend with your well-behaved pooch that much more.

Grooming and Boarding

Your dog's breed can affect your expenses. For example, some breeds require frequent grooming. And if you travel often, plan on paying boarding or pet-sitting fees. (Normally, you pay more to board a large dog.) No time for daily walks? You may need to pay a dog walker to give your pooch some exercise and a much needed bathroom break.

Okay, so dogs aren't cheap. The important part is that you know that up front so you understand the commitment. And remember, the right dog is a great investment in joy and companionship.