Reports of poisonings in cage birds are rare, since such poisonings are difficult to confirm and the bird’s restricted environment generally precludes ingestion of toxic substances. This is less true in the case of inhaled toxins such as carbon monoxide, insecticides, burned Teflon, and natural gas from cookstoves. Occasionally, however, altered circumstances do allow ingestion of harmful substances by a cage bird. The number of reports of avian poisonings will no doubt increase as more and more people own birds and demand increased veterinary care for them. This report deals with one such case.

A mature yellow-headed Amazon parrot (Amazona ocrocephala) was admitted to our hospital with a history of rapid onset of anorexia, incoordination so severe that the bird could not sit on its perch, depression, and loose droppings. The droppings contained small amounts of blood.

Further questioning disclosed that the bird did a great deal of chewing. So intense was the chewing behavior that the bird could not be let out of its cage unattended or it would damage furniture and other household objects. When confined to the cage the bird concentrated on chewing its perch, usually chewing completely through a hardwood dowel in less than two weeks.

The owner objected to the recurring expense of replacing the perch and had encased the last new perch in scrap sheet metal. This ploy did not deter the bird, and it promptly started shredding the metal, which was lead. This attack on the perch resulted in the prompt appearance of the clinical signs.

On physical examination, the bird was in good flesh, weighing 315 grams. It was well hand-tamed and had no clinical abnormalities except the presenting signs. A presumptive diagnosis of lead poisoning was made, based on the history and signs. Radiographs showed several small radiodense particles in the gizzard. These were assumed to be lead.

Treatment, begun immediately, consisted of the intravenous injection, at 12-hour intervals, of 17.5 mg calcium disodium edetate (Havidoteâ - Haver-Lockhart) diluted 1:2 with a 5% dextrose solution. The bird’s response was so dramatic that it appeared clinically normal after the second treatment. The route of administration was therefore switched to intramuscular, and a 1:4 dilution with 5% dextrose was used to minimize tissue reaction. (Dosage recommendation for calcium disodium edetate in birds could not be found, so I used the usual canine dosage of 100 mg/kg per day, divided into two or three doses.)

The bird was discharged from the hospital on the fourth day. A solution of Epsom salt was prescribed for use at home. This solution was made by dissolving one tablespoon of the crystals in 8 oz. of drinking water. The owner was instructed to put 1 ml. of this stock solution in the bird’s drinking cup with each change of water. During a two-year follow-up, the problem had not recurred.

Surgery to remove the lead from the bird’s gizzard was considered but was not performed due to the patient’s excellent response to medical treatment and to the anesthetic and mechanical difficulties inherent in such surgery. Also, the efficacy of removing the chips was questionable. Correlation is poor between the quantity of lead shot found in the gizzards of waterfowl (in which lead poisoning is fairly common) and the presence of illness. In fact, surgery is seldom indicated for the removal of lead, in the gastrointestinal tract or elsewhere.

Follow-up treatment with Epsom salt in birds has not been reported, and there is no proof that it helped prevent recurrence of signs in the case reported here. Use of the solution was prescribed in the hope that the small amount of Epsom salt the bird would ingest would not act as a laxative, but that the sulfate ion would combine with any dissolving lead to form the insoluble precipitate lead sulfate, which would be unavailable biologically and thus nontoxic.

I also recommended to the client that small branches from nontoxic trees such as maple, ash, and willow be put in the cage for the parrot to chew on. I believe that such branches are better for birds’ feet than dowels. For that reason, I routinely suggest that branches be substituted for commercial perches in the cages of all my avian patients, even if the bird is not inclined to chew its perch.

(Reprinted from "Veterinary Medicine Magazine/Small Animal Clinician," with the author's permission.)