Commitment and capacity: First consider whether you have the financial capacity and time to raise a pet. Dogs require veterinary care more often than other animals which could cost lot of money. They also require your time for walks and play.
Nutrition: The key here is to do your research. Web sites may tout about their products. You need to navigate the information highway very carefully. You can talk to friends who are raising pets, your veterinarian, and your pet store. Having a good understanding is the key.
Veterinary care: Selecting a veterinarian is also critical. Talk to your friends about their experience with veterinarian. Go online and do your own research on veterinarian in your area. Once you narrow the field to a few, have a talk with them before you select one.
Exercise and play: If you are raising a dog as your pet, you need to understand their need of daily exercises. Your interaction with other animals helps them to grow healthy.
Shelter: Understand the need of a properly sized shelter for each animal. Do not over stock your fish tank. Provide appropriate bedding for dogs and cats. Remember to change shelter requirements according to the season.