Just like people, birds need plenty of exercise and a balanced diet in order to stay fit. You should take your pet to the vet after you first buy it, and once a year afterward for an annual check-up. Your pet exercises best when it can fly freely, so it needs as much time out of the cage as you can reasonably give it.
Learn to recognise the signs when your bird is ill. It can be difficult to tell, but give your pet a regular check-over for symptoms such as:
You should also look out for unusual droppings - yellow, brown or black droppings can be indicators of health problems. Weight loss should also be a concern. Birds have extremely high metabolisms, so if they're not getting the nutrition they need it can affect them very quickly.
Another vital part of keeping your bird healthy is to ensure its cage is clean and its water and food are changed regularly. As well as making sure it has a clean environment to live in, this is a good way to monitor their food consumption and any changes in droppings.