Pat - The rust on the bottom of the cage will not cause heavy metal poisoning in your new bird. Parrots Cages are made of iron and powder coated.
Is your new bird showing these symptoms?:
Symptoms: feather picking, depression, gastrointestinal stasis, intermittent lethargy, seizures, dysphagia, ataxia, increased thirst and urination, loss of balance, dehydration, weight loss, green or bloody diarrhea and death.
Heavy metal poisoning comes from:
- Sources of Zinc: padlocks, galvanized cage wire and dishes, clips or staples, bird toy snaps, zippers, keys, nails, plumbing nuts, quick links, nuts on animal transport cages, hardware cloth, chrome, and some anti-rust paints, shampoos and skin preparations.
- Sources of Lead: tap water, solder, batteries, galvanized wire, hardware cloth, bells with lead clappers, linoleum, paints (lead-based, and those with leaded drying agents), stained glass, curtain weights, fishing and diving accessories, certain ceramic pieces, foil covering on champagne or wine bottles, leaded gasoline fumes, lead frames of stained glass windows and tiffany lamps.
If your bird does indeed have heavy metal poisoning, the cost is relevant to how serious it is. It could require a 24 hour or more stay in a vet hospital.
Once you have the blood drawn etc. to check, the treatment itself can be fairly cheap to cleanse the birds system.