As the saying goes, "one person's garbage is another person's treasure" at the flea market. While you're out there, a beautiful, slightly rusty birdcage may catch your eye.

Instantly you see how easy it would be to apply a paint job and turn it into a perfect Victorian home for your little bird. But before you splurge on this item, you may want to consider the potential risks. Although they are often stunning works of metallurgy and craftsmanship, they may be more suited for ferns instead of your canary.

The primary concern with antique birdcages is the potential for toxicity. Zinc and lead, both of which contain dangerous properties, were commonly used to create these works of art. Despite cleaning and painting, the zinc and lead are still there. As any bird owner knows, birds love to chew and nibble, and the outer paint surface can be quickly removed, so that soon the bird will begin chewing on the toxic metal.

The seed-guard mesh, common to many antique birdcages, is especially dangerous because they are usually crafted out of lead. Lead poisoning can cause devastating neurological damage. Zinc, meanwhile, can cause life-threatening anemia.

Size is another problem with antique birdcages. Most are made as decoration and do not provide adequate space for your bird to stretch his wings. Though he may look pretty sitting on his perch in the cage, to your bird, it may seem like a prison. Just because birds spend about 80 percent to 90 percent of their time perched doesn't mean they should not have a cage large enough for them to move, should the mood strike them.

So before you decide on the aesthetic beauty of a birdcage, consider the real-world risks first.