A recent discussion with a bird owner reminded me how critical this topic is. I wrote this article for another group about a year ago and decided it was an important subject that needed to be revisited and reprinted here.
A “heavy metal” is any relatively dense metal that is known for its potential toxicity, such as chromium, cobalt, arsenic, selenium, cadmium, antimony, mercury, thallium, and lead. These are relatively well known and recognized as toxic and dangerous, but did you know that Copper, Silver, Nickel, and Zinc are also toxic, heavy metals? Did you also know that nickel and zinc are used a LOT in parrot toys and aviaries?
Zinc is used everywhere. It’s typically the coating used for bells, clasps, chains, and hardware. It's used because it’s shiny and cheap. Galvanized steel is often used for outside enclosures and aviaries because steel will rust especially when used outside, but the galvanization process includes dipping the steel in many layers of zinc.
Nickel is another heavy metal that’s used for bells and hardware. Nickel is also a heavy metal that can be ingested and can result in heavy metal toxicity.
Silver is believed to be safe by some but it’s not. Pure silver is relatively soft, very malleable, and easily damaged so it is commonly combined with other metals to produce a more durable product. The most popular of these alloys (an alloy is a mixture of metals) is sterling silver, which consists of 92.5 percent silver and 7.5 percent copper, both of which are heavy metals.
Birds can ingest metals fairly easy because they use their beaks for everything from playing to climbing to, well, destruction (which to them IS playing). When metal gets into the system it can settle in the intestines. Over time these metals bind to and interfere with the functions of vital cellular components.
Heavy metals can bioaccumulate (become concentrated) in the body because they are hard to metabolize. Bioaccumulation occurs when the substance is absorbed at a rate faster than it can be removed by catabolism and excretion. So, the longer the biological half-life of a toxic substance the greater the risk of chronic poisoning, even if levels of the toxin are not very high.
The symptoms of Heavy Metal poisoning can look like other less serious health problems so some owners don't immediately recognize their bird is in a life-threatening situation.
If your parrot presents with vomiting, excessive thirst, tremors or falling, seizure, weakness of limbs, lethargy, or diarrhea (unexplained by diet change or that is chronic in nature) then you get to an Avian Vet for X-rays and blood work.
Why both? Because sometimes metal poisoning doesn’t show in the X-ray (if the particles are really small) and sometimes it doesn't show on blood work. When you go to your Vet tell him/her that you suspect heavy metal poisoning and ASK your vet to check for metal toxicity. If your vet wants to start chelation therapy then do it; it won't hurt your bird and it can save it's life.
Never let your bird roam your house without supervision. There are hundreds of things that will catch their eyes and make them want to explore more closely. Things like: wires, appliance cords, lead-glass windows, tiffany lamps, antique hardware, jewelry, and dozens of other interesting, shiny things that could all present the risk of heavy metal poisoning.
Change out hardware, including toy clasps, chains, and bells, with Stainless Steel equivalents if you aren't sure. Watch for changes in behavior and visible signs of illness and know the symptoms of metal toxicity.
If you suspect your bird has ingested metal always go straight to your Vet without delay. Take precautions, supervise, and know the sources and symptoms of Heavy Metal Poisoning. As the old adage goes … better safe than sorry so "err on the side of caution."
For more information on Heavy Metal and other toxins (including some human foods) go to http://avianmedicine.net/content/uploads/2013/03/37.pdf