Winter's coming, and what better way to save on heating costs than by adding a friendly dog or cat to warm the foot of your bed on those frigid, blustery nights.

But before you run to the pet shelter to pick up Rover or Fluffy, the personal finance Web site FiLife.com has these tips on budgeting for pet ownership:

• Estimate all the "start-up" costs and the "maintenance" costs of the pet. The American Society for the Prevention of Cruelty to Animals publishes estimates of the costs of adopting pets. The group estimates a medium-size dog will incur $565 in costs such as neutering, training and leashes, and $695 a year in annual upkeep.

• Slot those annual numbers into your budget. Be realistic. If a pet is going to stress your budget to a point of major discomfort, it's probably not a good idea.

• Prepare for surprises. Consider pet insurance or an emergency fund. Remember that puppies chew, cats claw, and fleas descend. Make sure you're prepared for the unexpected by signing up for pet insurance or by building up an emergency fund. You don't want to get stuck charging a four-figure vet bill to your credit card.

• If the numbers aren't adding up, make reasonable decisions. Often times, our hearts are bigger than our wallets. You could do your new four-footed friend more harm by not being able to provide for it after you bring it home.

Brian J. O'Connor