Especially if there is another pet already in the home. How quickly your new pet adjusts depends on their personality. Here are a few tips to help make bringing your new addition home a little easier.
Allow your new pet to familiarize itself with its new home. Temporarily confine existing pets to a room to give your new pet a chance to feel more comfortable with its surroundings.
Introduce your pets indoors, in controlled situations. Keep dogs on a leash and immediately put a stop to any aggressive behavior.
Give them time - don't force them together. Some pets are naturally more timid or unsure around other animals. Let pets adjust at their own pace. They may want to just sniff each other through a gate at first and that's fine. Give them time to gain confidence and decide when to face his or her new housemate.
Praise, praise, praise and give lots of rewards. Every time your new and old pet do something good with each other, praise and reward. The idea is to associate each other with good things!
When introducing a cat to a dog do NOT hold the cat in your arms. A frightened cat may scratch. Put the dog in a kennel or behind a secure gate and allow the cat to approach the dog. Never allow the dog to chase or corner the cat - even if it's out of playfulness or curiosity.
Give your pets separate food and water bowls, in separate spaces. If you are introducing cats, also provide separate litter boxes. Feed your new and existing pets in different locations to prevent any conflict over food.
Be especially careful when introducing dogs or cats to caged animals. Dogs and cats can live in harmony with rabbits, guinea pigs, birds, etc... but should be introduced under strictly controlled supervision. Remember, cats are very agile, so placing a cage high up on a shelf doesn't necessarily protect the caged pet.
Always supervise your pets until you are absolutely sure they get along. Until then, separate your pets by confining at least one of them to its own room. Only allow them to interact with each other with your supervision.