Excerpts from: ‘Treatment of a Hyacinth Macaw with Zinc Toxicity’ Information taken from an article by April Romagnano, PhD, DVM, Carol B. Grindem, DVM, PhD, Laurel Degernes, DVM, and Michele Mautino, DVM, PhD, entitled ‘Treatment of a Hyacinth Macaw with Zinc Toxicity’, Journal of Avian Medicine and Surgery 9(3):185-189, 1995.
Zinc is an essential trace metal. In birds, ingestion of excessive amounts of zinc results in toxicity resembling lead intoxication. Although not a common as lead intoxication, zinc poisoning is an important differential in a lethargic, depressed bird with loose, voluminous, malodorous, pale or brilliant lime-green feces. Other common signs of zinc toxicity in birds include anorexia, weight loss, dehydration, polyuria, polydipsia, ataxia, posterior paresis, and anemia. Hyperglycemia, seizures, and cyanosis, have also been reported in zinc-poisoned birds. Vomiting was reported in one green-winged macaw (Ara chloroptera) with zinc toxicity. Sources of zinc include galvanized cage wire and containers, cage clips or staples, bird toy snaps, zippers, US pennies minted after 1982, keys, nails, plumbing nuts, nuts on transport cages, and hardware cloth, as well as some paints, fertilizers, shampoos, skin preparations, and suppositories formulated with zinc. Zinc is absorbed in the proventriculus and the small intestine of chicks. In experimentally intoxicated chicks and cockatiels, zinc distributes to various tissues (eg. liver, kidney, and plasma), but the pancreas is the target organ. Focal mononuclear cell infiltrates and degeneration have been reported in the acini of the exocrine pancreas as well as in the liver and kidneys of zinc-poisoned birds. In addition to the pancreas, liver, and kidneys, the reproductive and gastrointestinal systems are also directly affected by zinc.