An epizootic of lead poisoning in greater flamingos (Phoenicopterus ruber roseus) in Spain

Diagnosis and Treatment of Heavy Metal Toxicosis in Six Waldrapp Ibis (Geronticus eremita)

Six adult Waldrapp ibis (Geronticus eremita) were presented with heavy metal toxicosis secondary to paint chip ingestion after being placed in an indoor confinement enclosure because of a regional highly pathogenic avian influenza epornitic and government restrictions. Four of the ibis developed clinical disease signs between 45 and 64 days of confinement, including weakness, lethargy, inability to fly, low body condition, and bilateral wing droop while 2 birds appeared to remain normal during that period. Common clinicopathological findings included elevated plasma aspartate aminotransferase, creatine kinase, glutamate dehydrogenase, and bile acids values. Erythrocyte morphological changes included prominent hypochromasia, decreased size of polychromatophils with occasional cytoplasmic stippling, abnormal shapes, and D cells. Whole-body radiographic imaging revealed particulate radio-opaque material in the ventriculus of all affected birds. One bird died before chelation therapy could be instituted and heavy metal testing of the liver revealed increased concentrations of lead and zinc. Lead toxicosis was diagnosed in the 5 remaining birds by plasma lead analysis. These 5 birds were hospitalized for an average of 40 days and treated with sodium calcium edetate and fluid therapy, which resulted in resolution of the toxicosis. Plasma biochemistry, complete blood counts, and blood lead values were performed repeatedly on all 5 birds and were used to guide therapy and monitor treatment response. This case series emphasizes the importance of early contingency planning and reviews the treatment of lead toxicosis in birds with a focus on long-term clinical monitoring and hematology.

The impact of environmental lead exposure on Whooper swan (Cygnus cygnus): Pathological and immunohistochemical studies

This study was carried out to investigate the pathology of environmental lead (Pb) poisoning in Whooper swans (Cygnus cygnus). A number of 12 out 54 swans (22.2%) randomly collected from Honshu, Japan from June 2005 to July 2007 were affected with Pb poisoning. Affected swans showed stained vent with greenish watery diarrhoea and impacted crop. The presence of Pb shots in the gizzard (50%) was confirmed by X-ray, and all cases showed a dark greenish coloured liver. Microscopically, the pathology of Pb poisoning in swans was multisystemic. The severity of the lesions was the highest in the CNS followed by the liver, kidney, spleen, lungs, gizzard, heart, bone marrow respectively and was the least in the peripheral nervous system. CNS lesions were cerebral haemorrhage, malacia, and spongiosis with astrocytic activation and increased neurofilaments accumulations. In addition, there were hepatic and renal hemosiderosis and apoptosis, hepatic granuloma, interstitial pneumonia, gizzard and myocardial necrosis and bone marrow hypoplasia. Chemical analysis of the Pb content in liver and kidneys ranged from 8.18 to 60.6 µg/g, respectively. The extent and severity of lesions varied among individuals and were mostly dose-dependent. Finally, these findings improved the diagnostic procedure of Pb poisoning in free-living Whooper swans.

Diseases of the Avian Urinary System

Diseases of the renal system can be caused by infectious and noninfectious processes. Creating a relevant differential diagnosis for kidney disease in the live or dead bird requires a structured approach where the list of differentials is narrowed based on the signalment of the bird; its history, including its diet and management; physical findings; and other diagnostic findings. This article aims to provide the reader not only a list of the diseases that occur in birds but also the guidelines on when a disease should be considered in a differential.

Lead pollution from waterfowl hunting in wetlands and rice fields in Argentina

The pollution of wetlands by lead derived from waterfowl hunting with lead shot was investigated. We determined soil pellet density and Pb concentration in soil, water and vegetation in natural wetlands and rice fields in central-eastern Santa Fe province, Argentina. Pellet density varied greatly among hunting sites (between 5.5-141 pellets/m(2)) and pellets were present in some control sites. Soil Pb concentration in most hunting sites (approximately 10-20 mg kg(-1)) was not much higher than in control sites (~5-10 mg kg(-1)), with the exception of the site with highest pellet density, which also had a high Pb soil concentration. In water, on the other hand, Pb concentration was similar in all sites (~4-7 μg L(-1)), both control and hunting, and higher than reference values for aquatic media. Lead was also present in vegetation, including grasses and rice crops, in almost all cases. Most soil-collection sites were slightly acidic, and were frequently flooded. These results strongly suggest that metallic Pb from spent shot is oxidized and dissolved due to wetland conditions. Thus, the pollutant is readily mobilized and distributed across all wetland areas, effectively homogenizing its concentration in locations with and without hunting activities. The replacement of lead by nontoxic materials in pellets appears to be the only effective way to prevent Pb pollution in wetlands.

Metals and trace elements in feathers: A geochemical approach to avoid misinterpretation of analytical responses

Assessing trace metal pollution using feathers has long attracted the attention of ecotoxicologists as a cost-effective and non-invasive biomonitoring method. In order to interpret the concentrations in feathers considering the external contamination due to lithic residue particles, we adopted a novel geochemical approach. We analysed 58 element concentrations in feathers of wild Eurasian Greater Flamingo Phoenicopterus roseus fledglings, from 4 colonies in Western Europe (Spain, France, Sardinia, and North-eastern Italy) and one group of adults from zoo. In addition, 53 elements were assessed in soil collected close to the nesting islets. This enabled to compare a wide selection of metals among the colonies, highlighting environmental anomalies and tackling possible causes of misinterpretation of feather results. Most trace elements in feathers (Al, Ce, Co, Cs, Fe, Ga, Li, Mn, Nb, Pb, Rb, Ti, V, Zr, and REEs) were of external origin. Some elements could be constitutive (Cu, Zn) or significantly bioaccumulated (Hg, Se) in flamingos. For As, Cr, and to a lesser extent Pb, it seems that bioaccumulation potentially could be revealed by highly exposed birds, provided feathers are well cleaned. This comprehensive study provides a new dataset and confirms that Hg has been accumulated in feathers in all sites to some extent, with particular concern for the Sardinian colony, which should be studied further including Cr. The Spanish colony appears critical for As pollution and should be urgently investigated in depth. Feathers collected from North-eastern Italy were the hardest to clean, but our methods allowed biological interpretation of Cr and Pb. Our study highlights the importance of external contamination when analysing trace elements in feathers and advances methodological recommendations in order to reduce the presence of residual particles carrying elements of external origin. Geochemical data, when available, can represent a valuable tool for a correct interpretation of the analytical results.

Lead exposure affects health indices in free-ranging ducks in Argentina

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.

Effects of lead shot ingestion on bone mineralization in a population of red-legged partridge (Alectoris rufa)

The effect of lead (Pb) toxicity on bone mineralization was investigated in a wild population of red-legged partridge (Alectoris rufa) inhabiting a farmland area contaminated with Pb-shot from recreational hunting activities in Albacete, a southeastern province of Spain. Femora from 40 specimens of red-legged partridge were analyzed for Pb by graphite furnace atomic absorption spectroscopy (GF-AAS), and for bone composition by Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). The FTIR and DRX data of bone were analyzed in detail to determine possible alterations in bone mineral chemistry and crystallinity due to Pb toxicity. Results showed a marked decrease in the degree of mineralization as Pb concentrations in bone tissue increased while XRD analyses showed that the crystallinity of apatite crystals increased with the Pb load in bone. These load-dependent effects are indicative that Pb contamination altered bone remodeling by reducing new bone mineral formation and demonstrate that bone quality is a sensitive indicator of adverse effects on wild bird populations exposed to Pb pollution.

Animal poisoning in Europe. Part 3: Wildlife

This review article is the third in a series on animal poisoning in Europe and represents a collation of published and non-published wildlife poisoning data from Belgium, France, Greece, Italy and Spain over the last 10 years. Birds, particularly waterfowl and raptors, were more commonly reported as victims of poisoning than wild mammals. In addition to specific but important toxicological disasters, deliberate primary or secondary poisonings are of concern to all countries. Metals (particularly lead arising from sporting/hunting activities) and pesticides (mainly anticholinesterases and anticoagulants) are frequent causes of poisoning, and often have fatal consequences. A more unified and consistent approach throughout European countries to improve the reporting and the analytical confirmation of wildlife poisoning would help to reduce the number of cases of malicious or negligent animal poisoning.

Metal levels in the bones and livers of globally threatened marbled teal and white-headed duck from El Hondo, Spain

El Hondo is a key area for marbled teal and white-headed duck. We present Pb, Cu, Zn, Se, and As data for bone and liver in birds found dead between 1996 and 2001. Several metals were higher in adult white-headed ducks than in marbled teal. They were higher in female than in male white-headed ducks, and did not differ with sex in marbled teal, but did by age. Lead in liver of adults was influenced by Pb shot ingestion, which was detected in 21% of marbled teal and in 71% of white-headed duck. No marbled teal had liver levels indicative of Pb poisoning, while 86% of white-headed ducks did. Selenium, Zn, and Cu were elevated in 13%, 7%, and 39% of birds, respectively. Whilst Pb shot poses the greatest threat to these species, further work should assess exposure via plants, invertebrates, water, and sediments for other metals, and investigate possible sub-lethal effects.

Heavy metals in flamingos (Phoenicopterus ruber) from Italian wetlands: the problem of ingestion of lead shot

Waterbirds are exposed to many contaminants, including lead from ingestion of shot and fishing sinkers. Lead poisoning had never been reported in flamingos wintering in Italian wetlands. Our investigation stems from a case of four flamingos found dead in Tuscany in 2002 with numerous lead shot in their gizzards. We therefore considered other specimens found dead in different Italian wetlands. Many lead shot found in gizzards and lead tissue concentrations confirmed the hypothesis of lead poisoning in two of the seven specimens analysed: concentrations in liver, kidney, and bone were 361.3, 265.09, and 43.31mug/g d.w., respectively. Lead organotropism was typical of acute poisoning. Cadmium and mercury were also determined, and found to be in line with what little data are available on this species in the literature. Although Italy recently endorsed the African-Eurasian Waterbird Agreement (AEWA) prohibiting use of lead shot for hunting in wetlands, our results reveal a first case of lead shot poisoning in flamingos wintering in Italian wetlands. This evidence sounds a further warning of the problem of spent lead shot in countries where hunting in wetlands is not strictly regulated.

The avian neurologic examination and ancillary neurodiagnostic techniques: a review update

The purpose of this article is to guide the avian clinician in the assessment of neurologic function in birds. Physical and neurologic examinations that evaluate cranial nerves, postural reactions, and spinal reflexes identify neurologic dysfunction and the corresponding anatomic location of the lesion. Ancillary diagnostic tests, such as cerebrospinal fluid analysis, diagnostic imaging, muscle and nerve histology, and electrodiagnostics, are tools to confirm and clarify conclusions from the neurologic examination and to identify the cause of disease. Once the disease location and pathologic process have been identified, appropriate treatment and prognosis may be provided.

Types of renal disease in avian species

Renal disease in birds is frequently encountered. Like most other animals, birds are susceptible to a full spectrum of renal insults,such as toxins, tumors, infections, and degenerative conditions. Accurate diagnosis of renal disease is based on a complete history,physical examination, and laboratory evaluation of the patient. Because it is often required for a more definitive diagnosis, special attention is given to histopathologic evaluation of renal tissue,whether through a premortem biopsy or collection at gross necropsy.

The effects of grit supplementation and feed type on steel-shot ingestion in mallards

Lead poisoning by shot-pellet ingestion is an important cause of death in waterfowl from wetlands that have high densities of lead-shot pellets and low availabilities of grit in their sediments. To evaluate grit supplementation when mixed with baited grain as a method of reducing shot ingestion in waterfowl, 24 mallards (Anas platyrhynchos) were kept in captivity to study the relationship between steel-shot, grit and grain ingestion in four experiments. Steel-shot ingestion was more related to seeking grit than to feeding on grain, and it did not differ between two types of grain offered (rice or sorghum). Grit ingestion increased with grit supplementation and shot ingestion was only slightly reduced. Calcareous grit used in the experiments had a shorter half-life (1.4 days) in the gizzard than values reported for siliceous grit (3.1 days).

Mortality incident in northern bald ibis Geronticus eremita in Morocco in May 1996

In May 1996 there was an acute and dramatic mortality incident in the last remaining wild population of northern bald ibis Geronticus eremita. This species is Critically Endangered, comprising only about 250 wild individuals, which occur on the Atlantic coast of southern Morocco. Over a period of 10 days a total of 38 adult birds (aged 1 year or more) died or disappeared. Deaths, probably secondary to the loss of one or both parent birds, also occurred subsequently in six estlings and one recent fledgling. The incident appeared to involve no other species. This paper describes the pattern of the incident, and pathological, microbiological and toxicological investigations and findings. Several features point to a toxic aetiology but the cause of the incident has not been established.

Lead shot pellets in the Ebro delta, Spain: densities in sediments and prevalence of exposure in waterfowl

Lead (Pb) poisoning has been found to be a serious problem for waterfowl in some southern European countries, but few studies have been conducted in Spain. In order to obtain these data, studies were made in the Ebro delta, a Spanish Ramsar site, during 1992 and 1993. Lead shot densities in the first 20 cm of sediment ranged from < 8 900 to 2 661 000 shot ha(-1). A similar proportion of birds had lead shot in the gizzard and elevated liver lead (> 5 microg g(-1) DW) concentrations. Northern pintail and common pochard (both with declining populations in Europe) showed the highest levels of shot ingestion, with 70.8 and 69.2%, respectively. Body condition index in the northern pintail was negatively correlated with the number of pellets in the gizzard and liver Pb concentration. Levels of exposure were higher than in other northern countries of the western Palearctic flyway, where lead shot have been banned recently.