Numerous experiments under controlled conditions and extensive investigation of waterfowl die-offs have demonstrated that exposure to lead from spent gunshot is highly detrimental to the health of waterfowl. However, few studies have focused on examining the more subtle sub-lethal effects of lead toxicity on ducks in non-experimental settings. In our study, the health of ducks exposed to varying amounts of lead under natural conditions was assessed by correlating individual lead exposure with relevant indices of health. Based on hunter-killed wild ducks in Argentina, we measured spleen mass, body condition, examined bone marrow smears, and determined Ca and P in bone tissue. In free-ranging live-trapped ducks we determined basic hematology and aminolevulinic acid dehydratase activity. Using multivariate analyses, we found that, when controlling for the potential confounding effect of site type, year, duck species, body mass and age, lead levels in the liver were negatively associated with body condition and spleen mass. Spleen mass was also lower in ducks with higher lead levels in their bones. In live ducks, high blood lead levels were associated with low packed cell volume and red cell morphologic abnormalities. These findings suggest that, despite the lack of recorded lead-induced mortality in the region, lead exposure results in less conspicuous but still significant impacts on the health of ducks, which could have serious implications for their conservation. Moreover, this evidence further supports the need for urgently banning lead shot in the region.

We conducted health assessments on 113 free-ranging raccoons ( Procyon lotor ) in Central Park, New York City, US, in February 2010, September 2010, and November 2011 in conjunction with a trap-vaccinate-release program to control a raccoon rabies epizootic. Five individuals were sampled at two time points for 118 raccoon examinations in total. We tested 13 of 13 and 8 of 13 euthanized raccoons for rabies and canine distemper virus (CDV), respectively, by antigen testing on brain tissue; all were negative for both viruses. Endoparasitism was the most common necropsy finding, with definitive identification of Baylisascaris procyonis in six of eight (75%) necropsied raccoons. Multiple intestinal parasites were detected in feces of living raccoons, including ascarid-type ova in 25 of 80 (31%) raccoons, with B. procyonis confirmed in one sample. Median blood lead level was 7.3 μg/dL (n=104). Rabies virus neutralizing antibody titer was ≥0.5 IU/mL in 9 of 88 (10%) raccoons naive to rabies vaccination and in 13 of 20 (65%) previously vaccinated raccoons. The majority of raccoons we tested were seropositive for canine parvovirus-2 (54/59, 92%) and Toxoplasma gondii (39/60, 65%). Fewer were seropositive for Rickettsia rickettsii (3/30, 10%). None were seropositive for CDV (n=108), canine adenovirus-1 (n=60), or Borrelia burgdorferi (n=30). Ectoparasites found during 16 of 118 (13.6%) physical examinations included Ixodes texanus ticks (15/118, 12.7%) and Trichodectes octomaculatus lice (1/118, 0.8%). We detected Campylobacter jejuni in 5 of 79 (6%) fecal samples. We detected 11 Salmonella enterica serotypes in 70 of 111 (63.1%) enteric cultures, the most common of which were Salmonella Newport (20/70, 29%) and Salmonella Oranienburg (20/70, 29%). These results indicate that raccoons in Central Park likely are involved in the environmental occurrence and potential disease transmission of a variety of infectious and noninfectious diseases of concern for human, wildlife, and domestic animal health.