title: Lead toxicity in captive and wild Mallards (Anas platyrhynchos) in Spain.
abstract: Forty captive Mallards (Anas platyrhynchos), of both sexes, were separated into five groups and dosed with lead shot via oral intubation; one group was used as a control. Lead dosage differed in terms of shot number and size, as well as administration time. One hundred and thirty-five wild mallards were trapped between 1998 and 2001 in the Boada and Nava lagoons near the Canal de Castilla, in the Spanish province of Palencia. Radiologic techniques (ventrodorsal and lateral views) were used to detect lead shot in the gizzard and to determine degradation in dosed birds over time. Heparinized blood samples were taken from wild and captive mallards and blood lead levels were determined using anodic stripping voltammetry with a dropping mercury electrode. Clinical signs, injuries, and body weight were recorded. In approximately 90% of the experimentally dosed mallards, administered shot stayed in their gizzard until it degraded; this took approximately 30 days. Peak lead levels in blood were observed between days 10 and 20, and 10 days following a repeat dosage; males were more sensitive than females to a repeat dosage. During the experimental phase, 34% of birds died, and those that survived had varying degrees of anorexia, lethargy, and a decreased response to external stimulus. Of 135 tested wild mallards, 41% had a blood lead concentration higher than 0.200 microg/g. Lead shot was found embedded in 3.6% of the wild birds and 1.2% had a lead shot pellet in their gizzard.
authors.affiliation: Department of Animal Medicine, Veterinary Faculty, University of León, León, Spain.
authors.forename: Juan José
authors.initials: JJ
authors.lastname: Rodríguez
authors.forename: Paula A
authors.initials: PA
authors.lastname: Oliveira
authors.forename: Luis Eusebio
authors.initials: LE
authors.lastname: Fidalgo
authors.forename: Mário M D
authors.initials: MM
authors.lastname: Ginja
authors.forename: António M
authors.initials: AM
authors.lastname: Silvestre
authors.forename: Cesar
authors.initials: C
authors.lastname: Ordoñez
authors.forename: Alicia Ester
authors.initials: AE
authors.lastname: Serantes
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Gonzalo-Orden
authors.forename: María Asunción
authors.initials: MA
authors.lastname: Orden
mesh_terms: D000818:Animals; D000835:Animals, Wild; D001715:Bird Diseases / Q000097:blood* / Q000139:chemically induced* / Q000401:mortality; D004305:Dose-Response Relationship, Drug; D004372:Ducks; D005260:Female; D005895:Gizzard, Avian / Q000737:chemistry; D007854:Lead / Q000008:administration & dosage / Q000097:blood / Q000633:toxicity*; D007855:Lead Poisoning / Q000097:blood / Q000401:mortality / Q000662:veterinary*; D008297:Male; D013030:Spain
chemical_list: D007854:Lead