Kinetics of lithium as a lithium chloride dose suitable for conditioned taste aversion in lactating goats and dry sheep.

Lithium chloride (LiCl) is widely used for inducing conditioned taste aversion (CTA) so that livestock will reduce or avoid ingestion of toxic plants and graze groundcover mingled with valuable crops. However, pharmacokinetic studies of LiCl at effective CTA doses are lacking. With this aim, 6 Murciano-Grandina dairy does during late lactation and 6 dry Manchega dairy ewes were orally dosed with 200 and 225 mg LiCl/kg BW, respectively. Does were placed in metabolism cages whereas ewes were group fed in pens. Lithium was measured over 168 (does) and 192 h (ewes) at predefined intervals in plasma, urine, feces, and milk using flame atomic absorption spectroscopy. Plasma Li concentrations reached a maximum at 4 h in does (13.4 ± 1.35 mg Li/L) and 12 h in ewes (17.7 ± 0.8 mg Li/L). The calculated plasma half-lives were 40.3 ± 3.8 and 30.9 ± 2.1 h for does and ewes, respectively. In goats, all Li administered was recovered at 96 h (92 ± 4% in urine, 6.5 ± 1.3% in feces, and 2.8 ± 0.4% in milk); however, the estimated clearance time in feces was 11 and 9 d for does and ewes, respectively. Additionally, maximum Li excretion in doe milk was 15.6 ± 0.5 mg/L, which was approximately half of the calculated effective dose for a 5-kg BW sucking kid. In conclusion, Li kinetics in goats and sheep were similar to cattle and elimination took longer than in monogastric species. The low concentration of Li in feces, urine, and milk, as well as the complete elimination of Li from the body after 1.5 wk allows us to conclude that LiCl is safe and suitable for inducing CTA in ruminants.

Persistent organochlorine residues in livers of six species of Ciconiiformes (aves) from Spain.

Liver samples of 42 birds belonging to 6 species of Ciconiiformes (grey heron (n = 17), little egret (n = 12), cattle egret (n = 1), glossy ibis (n = 1), little bittern (n = 1), and white stork (n = 10)), collected from two different zones of Spain (Ebro Delta and Madrid) in 1992-1997, were analyzed for organochlorine pesticides and PCBs. SigmaPCBs (sum of concentrations of individual congeners), p,p'-DDE, HCB, gamma-HCH, and heptachlor epoxide were the most prevalent residues detected in all samples (occurrence > 95%). There were no statistically significant differences in organochlorine levels between grey herons and little egrets, while levels of SigmaPCBs, p,p'-DDE, HCB, gamma-HCH, and heptachlor were significantly lower for white storks. These results could be explained by the different habitat of these species, aquatic in the Ebro Delta (grey herons, little egrets) and dry in Madrid (white stork), and their diverse feeding habits.

Heavy metals in livers of waterbirds from Spain.

Wetlands tend to accumulate heavy metals from local sources, such as Pb shot used for waterfowl hunting, and from regional sources, such as atmospheric deposition and riverine or marine inputs. We determined concentrations of six heavy metals (Cr, Mn, Cu, Zn, Cd, and Pb) in livers of waterbirds shot by hunters in five Spanish wetlands to study the different factors that can contribute to the accumulation of these metals (sex, age, diet, grit, and Pb shot ingestion). Differences among wetlands were observed only for Cr, Cu, and Cd. Differences among species were observed for all the metals, and Cu was notably higher in pochards (Aythya and Netta genus) than in other waterfowl. Cu, Zn, and Cd concentrations increased with age, and only Pb showed differences related to sex, with males having higher concentrations than females. Most metals other than Pb were correlated with each other. Lead was dependent on Pb shot ingestion. Grit ingestion positively correlated with concentrations of Cr and to a lesser extent with Mn, Zn, and Cd. Ingestion of grit or shot may obscure relationships between metals and diet. Herbivorous species, which had more grit in the gizzard, had higher Cr, Zn, and Cd concentrations. Granivorous birds, which have the highest rates of Pb shot ingestion, had the highest concentrations of Pb. Grit and Pb shot ingestion are both important sources of heavy metals for waterbirds. Lead was the single metal studied whose concentrations exceeded toxicity thresholds.

Marine debris ingestion in loggerhead sea turtles, Caretta caretta, from the Western Mediterranean.

Marine debris represents an important threat for sea turtles, but information on this topic is scarce in some areas, such as the Mediterranean sea. This paper quantifies marine debris ingestion in 54 juvenile loggerhead sea turtles (Caretta caretta) illegally captured by fishermen in Spanish Mediterranean waters. Curved carapace length was measured, necropsies were performed and debris abundance and type was recorded. Different types of debris appeared in the gastrointestinal tract of 43 turtles (79.6%), being plastics the most frequent (75.9%). Tar, paper, Styrofoam, wood, reed, feathers, hooks, lines, and net fragments were also present. A regression analysis showed that the volume of debris increased proportionally to the size of the turtles. The high variety of debris found and the large differences in ingestion among turtles indicated low feeding discrimination of this species that makes it specially prone to debris ingestion. Our data suggest that more severe control of litter spills and greater promotion of environmental educational programmes are needed in the Western Mediterranean.

A review of the effects of agricultural and industrial contamination on the Ebro delta biota and wildlife.

The Ebro delta (NE Spain) is a 320 km2 wetland area of international importance for conservation. The area is devoted to rice farming and receives large amounts of pesticides. Industrial pollutants are also carried to the delta by the river. The information accumulated during the last 25 year on the effect of such pollution on the biota is reviewed in order to identify the existing gaps and needs for management. Organochlorine pesticides were legally used until 1977, which has resulted in the widespread presence of these compounds in the Ebro delta biota. Lethal, sublethal or other detrimental effects of these pesticides on wildlife in the area were poorly investigated, but negative effects on the reproduction of ducks and herons were reported. Nowadays, polychlorinated biphenyls (PCBs) are the main responsible of organochlorine pollution in the area: concentrations in biota samples are higher than levels observed in nearby coastal areas, as a result of the significant PCB inputs by the river which, in 1990, were evaluated at 126 kg yr(-1). The massive use of herbicides is thought to have contributed to the elimation of macrophyte vegetation in the lagoons during the eighties, which had strong consequences on diving ducks and coot populations. Weed control is also related to the loss of biodiversity held by rice fields. The massive and inadequate use of organophosphorus and carbamate pesticides (involving more than 20,000 t yr(-1) has produced some waterbird mortality events, and may have direct and indirect effects on other non-target organisms. The accumulation in the soil of lead pellets used in waterfowl shooting is estimated to kill some 16,300 waterbirds in the Ebro delta every year.

Multiple inert gas elimination technique for determining ventilation/perfusion distributions in rat during normoxia, hypoxia and hyperoxia.

1. The use of the multiple inert gas elimination technique (MIGET) in quantifying ventilation/perfusion distributions (V*A/Q*) in small animals, such as the rat, may cause results to be biased due to haemodilution produced by the large volume of liquid infused intravenously. 2. We tested two methods of administering inert gases in rats using the MIGET: (i) standard continuous intravenous administration of inert gases (method A); and (ii) a new method based on the physicochemical properties of each inert gas (method B). This method included acute simultaneous inert gas administration using three pathways: inhalation, intravenous infusion and rectal infusion. Both MIGET methods were applied to obtain data while breathing three different inspiratory fractions of oxygen (FIO2): normoxia, hypoxia and hyperoxia. 3. Inert gas levels obtained from blood or expired air samples were sufficient for chromatographic measurement, at least during a 2 h period. The V*A/Q* distributions reported using both methods were acceptable for all the physiological conditions studied; therefore, the alternative method used here may be useful in further MIGET studies in rats because haemodilution resulting from continuous intravenous infusion of less-soluble gases can be avoided. 4. Normoxic rats showed lower mean values of the V*A/Q* ratio of ventilation distribution and higher mean values of the V*A/Q* ratio of perfusion distribution with the usual method of inert gas administration (method A). These non-significant differences were observed under almost all physiological conditions studied and they could be caused by haemodilution. Nevertheless, the effect of interindividual differences cannot be discarded. An additional effect of the low haematocrit on cardiovascular changes due to low FIO2, such as pulmonary vasoconstriction or increased cardiac output, may explain the lower dispersion of perfusion distributions found in group A during hypoxia.

Lead shot ingestion in two raptor species from Doñana, Spain.

Diurnal raptors inhabiting wetland areas where waterfowl shooting is conducted have many opportunities to ingest lead (Pb) shot pellets when feeding on their prey. Exposure to Pb shot was studied in the Spanish imperial eagle (Aquila adalberti), an endangered species with a world population of about 150 breeding pairs, and in the red kite (Milvus milvus) from Doñana (southwest Spain). Lead exposure was evaluated by the presence of Pb shot in the pellets of both species. Results obtained by this noninvasive method demonstrated Pb shot in 11.0% of Spanish imperial eagle and 5.5% of red kite pellets. When the data of both species were pooled, there was a significant relationship between Pb shot ingestion and consumption of waterfowl during the hunting season. Pb shot found in pellets exhibited signs of erosion, and their weight distribution had peaks at 70, 170, and 240 mg, which could correspond to ammunition used for duck and goose hunting.

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).

Comparison of residue levels of persistent organochlorine compounds in butter from Spain and from other European countries.

Commercially available butter from Spain (n = 36) and from other European countries (n = 20) has been analyzed by high resolution gas chromatography with an electron capture detector for organochlorine contaminants. The results showed that both groups of samples have a similar pattern of these pollutants, but in all cases where significant differences in concentrations were found, Spanish samples presented higher values. This was especially notable for lindane (median values 11.6 vs. 3.0 ng/g wet weight), hexachlorobenzene (6.4 vs. 0.5) and beta-hexachlorocyclohexane (3.1 vs. 1.2). Total PCBs showed no differences (5.4 vs. 6.6), but detailed analysis of congener composition indicated a higher presence in Spanish samples of the most persistent chlorinated PCBs. No sample presented levels of concern for any single organochlorine compound. It is interesting to note that consumption of butter in Spain is low so, although levels of organochlorines are higher than those found in other countries, consumers are less exposed through this foodstuff than in other European countries. These results also confirm the fact that environmental pollution by organochlorines is more important in Spain than in the rest of Europe.

Animal poisonings: the 10-year experience of a veterinary analytical toxicology laboratory.

Data on 10-y of chemical toxicological analyses carried out in a veterinary laboratory in Barcelona, Spain for suspected wild and domestic animal poisonings are summarized. The 218 cases involved more than 1 million animals, some 7,500 of which died. Pesticides, especially insecticides (46.6%) and rodenticides (37.9%), were frequently involved. Strychnine (n = 11) and aldicarb (n = 10) were the most usual toxic agents in baits prepared for intentional poisonings; other cases involved pentachlorophenol, hexachlorocyclohexane or anticoagulant rodenticides. Service to veterinarians and others could be improved if a coordinated network of national and regional Animal Poison Centers were created.

Comparative study on the fatty acid composition of two marine vertebrates: striped dolphins and loggerhead turtles.

The fatty acid composition of total lipids extracted from seven different tissues (fat, liver, cerebrum, cerebellum, lung, kidney and muscle) of 10 striped dolphins (Stenella coeruleoalba) (weight 75.7 +/- 16.2 kg) found dead or moribund during a morbillivirus epizootic, and from two tissues (fat and liver) of 54 loggerhead turtles (Caretta caretta) (18.5 +/- 10.5 kg) seized dead after illegal capture, both from the Mediterranean Sea, have been determined by high resolution chromatography techniques. When comparing both species, fatty acid composition is surprisingly similar, with a predominance of the monoenoic followed by the saturated group of fatty acids, and a very close ratio of polyunsaturates n-3/n-6. The relatively high arachidonic acid content in the liver of the two marine species is remarkable. The similar diet can play an important role in these findings, but it is suggested that probably metabolic pathways and essential fatty acid requirements between both marine vertebrates are similar, more than is expected from their earlier filogenetic evolutionary divergence.

High Prevalences of Lead Poisoning in Wintering Waterfowl in Spain

Some Mediterranean wetlands are found between the areas with the highest prevalence of lead pellet exposure for waterfowl in the world. To assess the situation in Spain, availability of pellets in sediments and rates of ingestion by waterfowl were determined in four important wetlands: Albufera de València, El Fondo, Tablas de Daimiel, and Doñana (Guadalquivir Marshes). Lead pellet density in sediment was maximum in the Albufera, with 2.8 million pellets/ha. In Tablas de Daimiel, where hunting was banned in 1965, about 1.0 million pellets/ha were found. Percentages of shot waterfowl with ingested pellets were maximum in the wetlands on the Mediterranean coast (El Fondo and Albufera de València): 87.5% of common pochard (Aythya ferina) and approximately 33% of mallard (Anas platyrhynchos) and shoveler (Anas clypeata) contained ingested pellets. It was found that mallards with > 5 µg/g dry weight of lead in the liver had 8.5% lower body condition and 7.7% less body weight than birds with lower lead concentrations. Moreover, lead poisoning was diagnosed as the cause of death in 16 out of 75 birds, mainly greylag geese (Anser anser), found dead in some of these zones.

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

During November 1992 to March 1993, and November 1993 to February 1994, 106 greater flamingos (Phoenicopterus ruber) were collected dead or moribund in the wetlands of El Fondo and Salinas de Santa Pola, eastern Spain. Birds still alive were emaciated and had a bile-stained diarrhea. On necropsy, they had liquid in the upper digestive tract and the walls of their gizzards were stained dark green. Fifty-three (93%) of 57 gizzards examined contained lead shot (range one to 277 shot), and fifty-five (96%) of 57 livers contained levels of lead greater than 5 micrograms/g dry weight (DW) (median = 192.3 micrograms/g DW, range < 2.5 to 992.2 micrograms/g DW).