Spaying and Neutering
Spaying or neutering your pet is the most responsible thing to do. Most pets are not breeding quality in the first place- even though I'm sure you feel your dog is adorable. Dogs who are unaltered have a higher risk of cancer, and are more likely to try to run away.
Some say that by altering the dog, you are going to change the dog- this is not true. Some dogs tend to mellow out a tad, and this may cause weight gain- you can prevent this by giving more exercise to the dog. The surgery to alter the dog is very common, and there is little risk involved to the dog. There is more risk of your dog getting cancer from not being altered than there is with the surgery.
Another myth is that it's best to let your female have at least one litter before you spay her. There is no need for this at all. Having a litter only makes more dogs, which will need homes. A female who has had a litter of pups prior to being spayed isn't going to make things better for her. You also have to take into account the risk of complications during her pregnancy, and delivery. Not all dogs can have the puppies on their own- they require a human to be there to help them, cut the cord, etc., and that requires either a vet or someone who is very knowledgable in whelping a litter. Sometimes puppies won't nurse, and have to be tubefed every couple of hours- tubefeeding requires you to put a tube down the puppies throat and administer food through a syringe- not an easy task.
Females go into "season" every six months, and the season lasts for over 20 days. When a female is in season they have a bloody discharge which will be on your carpet, furniature and bed. You can purchase diapers for her, but a lot of dogs will chew them off due to discomfort.
Spaying the dog will prevent all of this. If you have a male, you should neuter to prevent testicular cancer and help prevent the dog from running off to mate- males can smell a female in heat from great distances, and will wonder off to find her.
If you cannot afford to spay or neuter your dog, contact your local shelter. Most of them offer coupons to get your dog altered at a discounted rate, or even for free. If you get a dog from a shelter, most will either be already altered, or will give you a voucher to have them neutered for free when they turn six months old.
If you're still not convinced that altering your pet is best, consider this: A lot of cities are cracking down on pet over-population. Many now have limits on the number of un-altered pets allowed (limit is one), and they charge you a high fee to get the pets license. In some cities it's $100 or more, per year. To license an altered dog, the fee is only a few dollars per year.