Sin Nombre virus (SNV) is an etiologic agent of hantavirus pulmonary syndrome. To better understand the natural history of this virus we studied population dynamics and temporal pattern of infection of its rodent hosts in southeastern Colorado (USA) from 1995 to 2000. We present evidence for the presence of two hantaviruses, SNV in deer mice (Peromyscus maniculatus) and El Moro Canyon virus in western harvest mice (Reithrodontomys megalotis), at our study sites. Sin Nombre virus appeared only sporadically in deer mouse populations; overall prevalence of antibody to SNV was 2.6%. El Moro Canyon virus was enzootic: seroconversions occurred throughout the year; antibody prevalence (11.9% overall) showed a delayed–density-dependent pattern, peaking as relative abundance of mice was declining. Males of both host species were more frequently infected than were females. An apparently lower mean survivorship (persistence at the trapping site) for SNV antibody-positive deer mice could indicate a detrimental effect of SNV on its host, but might also be explained by the fact that antibody-positive mice were older when first captured.

We followed seasonal and year-to-year population dynamics for a diverse rodent assemblage in a short-grass prairie ecosystem in southeastern Colorado (USA) for 6 yr. We captured 2,798 individual rodents (range, one to 812 individuals per species) belonging to 19 species. The two most common species, deer mice (Peromyscus maniculatus) and western harvest mice (Reithrodontomys megalotis), generally had population peaks in winter and nadirs in summer; several other murid species demonstrated autumn peaks and spring nadirs; heteromyids were infrequently captured in winter, and populations generally peaked in summer or autumn. Interannual trends indicated an interactive effect between temperature and precipitation. Conditions associated with low rodent populations or population declines were high precipitation during cold periods (autumn and winter) and low precipitation during warm periods (spring and summer). Severity of adverse effects varied by species. Heteromyids, for example, were apparently not negatively affected by the hot, dry spring and summer of 2000. Cross-correlations for the temporal series of relative population abundances between species pairs (which are affected by both seasonal and interannual population dynamics) revealed positive associations among most murids and among most heteromyids, but there were negative associations between murids and heteromyids. These results have important implications for those attempting to model population dynamics of rodent populations for purposes of predicting disease risk.

We examined data collected by the US Sea Turtle Stranding and Salvage Network on 4,328 green turtles (Chelonia mydas) found dead or debilitated (i.e., stranded) in the eastern half of the USA from Massachusetts to Texas during the period extending from 1980 to 1998. Fibropapillomatosis (FP) was reported only on green turtles in the southern half of Florida (south of 29°N latitude). Within this region, 22.6% (682/3,016) of the turtles had tumors. Fibropapillomatosis was more prevalent in turtles found along the western (Gulf) coast of Florida (51.9%) than in turtles found along the eastern (Atlantic) coast of Florida (11.9%) and was more prevalent in turtles found in inshore areas (38.9%) than in turtles found in offshore areas (14.6%). A high prevalence of FP corresponded to coastal waters characterized by habitat degradation and pollution, a large extent of shallow-water area, and low wave energy, supporting speculation that one or more of these factors could serve as an environmental cofactor in the expression of FP. A high prevalence of FP did not correspond to high-density green turtle assemblages. Turtles with tumors were found most commonly during the fall and winter months, and the occurrence of tumors was most common in turtles of intermediate size (40–70-cm curved carapace length). Stranded green turtles with tumors were more likely to be emaciated or entangled in fishing line and less likely to have propeller wounds than were stranded green turtles without tumors. Turtles with and without tumors were equally likely to show evidence of a shark attack. The percent occurrence of tumors in stranded green turtles increased from approximately 10% in the early 1980s to over 30% in the late 1990s. Fibropapillomatosis was first documented in southernmost Florida in the late 1930s and spread throughout the southern half of Florida and the Caribbean during the mid-1980s. Because green turtles living in south Florida are known to move throughout much of the Caribbean, but are not known to move to other parts of the USA or to Bermuda, the spread and current distribution of FP in the western Atlantic, Gulf of Mexico, and Caribbean can be explained by assuming FP is caused by an infectious agent that first appeared in southern Florida. Aberrant movements of captive-reared turtles or of turtles that are released into areas where they were not originally found could spread FP beyond its current distribution.

We investigated the epidemiology of the European brown hare syndrome (EBHS) in Finland among free-living mountain hares (Lepus timidus) and European brown hares (Lepus europaeus). Carcasses of 297 European brown hares and 843 mountain hares submitted for postmortem examination were analyzed between 1990 and 2002. One hundred thirty-six cases of EBHS were detected during the examination, 20 cases in European brown hares and 116 in mountain hares. Liver samples from 56 histopathologically positive and 135 negative cases were analyzed by reverse transcription polymerase chain reaction (RT-PCR). The results of RT-PCR correlated well with histopathology. Cases of EBHS appeared only sporadically in a restricted area in eastern Finland during 1990–97. In 1998, the number of cases increased, and the disease spread to the north. In 1998–99, EBHS was the most common disease of mountain hares in necropsy material from northern and eastern Finland. Special features were the occurrence of the disease in areas in which European brown hares are rare and the seasonal distribution of cases, most of which appeared in spring or summer. This is the first report of an outbreak of EBHS occurring mainly among free-living mountain hares from Finland.

We collected samples from apparently healthy geese in the Playa Lakes Region (USA) during the winters of 2000–01 and 2001–02 to determine whether carriers of Pasteurella multocida, the bacterium that causes avian cholera, were present in wild populations. With the use of methods developed in laboratory challenge trials (Samuel et al., 2003a) and a serotype-specific polymerase chain reaction method for identification of P. multocida serotype 1, we found that a small proportion of 322 wild birds (<5%) were carriers of pathogenic P. multocida. On the basis of serology, an additional group of these birds (<10%) were survivors of recent avian cholera infection. Our results confirm the hypothesis that wild waterfowl are carriers of avian cholera and add support for the hypothesis that wild birds are a reservoir for this disease. In concert with other research, this work indicates that enzootic infection with avian cholera occurs in lesser snow goose (Chen caerulescens caerulescens) populations throughout their annual cycle. Although fewer Ross's geese (Chen rossii) were sampled, we also found these birds were carriers of P. multocida. Even in the absence of disease outbreaks, serologic evidence indicates that chronic disease transmission and recent infection are apparently occurring year-round in these highly gregarious birds and that a small portion of these populations are potential carriers with active infection.

Serum samples from 106 Eurasian lynx (Lynx lynx) from across Sweden, found dead or shot by hunters in 1993–99, were investigated for presence of antibodies to feline parvovirus (FPV), feline coronavirus, feline calicivirus, feline herpesvirus, feline immunodeficiency virus, Francisella tularensis, and Anaplasma phagocytophila, and for feline leukemia virus antigen. In addition, tissue samples from 22 lynx submitted in 1999 were analyzed by real-time polymerase chain reaction (PCR) to detect nucleic acids specific for viral agents and A. phagocytophila. Except for FPV antibodies in one lynx and A. phagocytophila in four lynx, all serology was negative. All PCR results also were negative. It was concluded that free-ranging Swedish lynx do not have frequent contact with the infectious agents considered in this study.

A total of 294 sera collected between 1999 and 2001 from eight captive and one free-ranging herds of Arabian oryx (Oryx leucoryx) distributed in Saudi Arabia (SA) and the United Arab Emirates (UAE) were assayed for antibodies against 13 selected viral agents. Arabian oryx have been exposed to bluetongue virus (BTV), epizootic hemorrhagic disease virus (EHDV), rinderpest virus (RPV), bovine respiratory syncytial virus (BRSV), bovine adenovirus 3 (BAV-3), cervid herpesvirus-1, foot-and-mouth disease virus, equine herpesvirus 9, and bovine viral diarrhea virus. The high seroprevalence to BTV and EHDV in the UAE and SA indicates that Arabian oryx are likely to be susceptible to infection by these viruses and therefore could act as a source of virus to vectors during the infective stage of infection. Moreover, antibodies were detected against RPV and BRSV in sera from SA and against BAV-3 in sera from the UAE. No antibodies were found against bovine herpesvirus-1, caprine herpesvirus-1, enzootic bovine leucosis virus, and peste des petits ruminants virus. On the basis of these results, caution should be applied when considering translocation of Arabian oryx, and only those proven to be free of infectious agents that might present a risk to other species should be moved.

A total of 51 sera from a migratory population of Burchell's zebras (Equus burchelli) were collected in the Serengeti National Park (Tanzania) between 1999 and 2001 to assess levels of exposure to equine herpesvirus types 1, 2, 4, 9 (EHV-1, −2, −4, −9), EHV-1 zebra isolate T965, and equine arteritis virus (EAV). Using virus-specific neutralizing antibody tests, seroprevalence was high for EHV-9 (60% of 45), moderate for EAV (24% of 51), and lower for the EHV-1-related zebra isolate (17% of 41), EHV-1 (14% of 49), and EHV-4 (2% of 50). No evidence for exposure to EHV-2 was found (0% of 51). The high level of exposure to EHV-9 is interesting because evidence of infection with this virus has not been previously described in any wild equine population. Although the epidemiology of EHV-9 in Burchell's zebras is presently unknown, our results suggest that in East Africa, this species may be a natural host of EHV-9, a neuropathogenic virus that was only recently isolated from captive Thomson's gazelles (Gazella thomsoni) in Japan. There is currently no evidence that EHV-9 induced mortality in Burchell's zebras in the Serengeti, but because of the reported virulence of this virus for more susceptible species such as Thomson's gazelles, viral transmission from infected zebras to ungulates may result in mortality.

We anesthetized and blood sampled wild big brown bats (Eptesicus fuscus) in Fort Collins, Colorado (USA) in 2001 and 2002 and assessed effects on survival. Inhalant anesthesia was delivered into a specially designed restraint and inhalation capsule that minimized handling and bite exposures. Bats were immobilized an average of 9.1±5.1 (SD) min (range 1–71, n=876); blood sample volumes averaged 58±12 μl (range 13–126, n=718). We randomly selected control (subject to multiple procedures before release) and treatment (control procedures plus inhalant anesthesia and 1% of body weight blood sampling) groups in 2002 to assess treatment effects on daily survival over a 14-day period for adult female and volant juvenile bats captured at maternity roosts in buildings. We monitored survival after release using passive integrated transponder tag detection hoops placed at openings to selected roosts. Annual return rates of bats sampled in 2001 were used to assess long-term outcomes. Comparison of 14-day maximum-likelihood daily survival estimates from control (86 adult females, 92 volant juveniles) and treated bats (187 adult females, 87 volant juveniles) indicated no adverse effect from anesthesia and blood sampling (juveniles: χ²=22.22, df=27, P>0.05; adults: χ²=9.72, df=18, P>0.05). One-year return rates were similar among adult female controls (81%, n=72, 95% confidence interval [CI] =70–91%), females treated once (82%, n=276, 95% CI=81–84%), and females treated twice (84%, n=50, 95% CI=74–94%). Lack of an effect was also noted in 1-yr return rates of juvenile female controls (55%, n=29, 95% CI=37–73%), juveniles treated once (66%, n=113, 95% CI=58–75%), and juveniles treated twice (71%, n=17, 95% CI=49–92%). These data suggest that anesthesia and blood sampling for health monitoring did not measurably affect survival of adult female and volant juvenile big brown bats.

In September and October 2002, an epizootic of neurologic disease occurred at an alligator farm in Florida (USA). Three affected American alligators (Alligator mississippiensis) were euthanatized and necropsied, and results confirmed infection with West Nile virus (WNV). The most significant microscopic lesions were a moderate heterophilic to lymphoplasmacytic meningoencephalomyelitis, necrotizing hepatitis and splenitis, pancreatic necrosis, myocardial degeneration with necrosis, mild interstitial pneumonia, heterophilic necrotizing stomatitis, and glossitis. Immunohistochemistry identified WNV antigen, with the most intense staining in liver, pancreas, spleen, and brain. Virus isolation and RNA detection by reverse transcription–polymerase chain reaction confirmed WNV infection in plasma and tissue samples. Of the tissues, liver had the highest viral loads (maximum 10^8.9 plaque-forming units [PFU]/0.5cm³), whereas brain and spinal cord had the lowest viral loads (maximum 10^6.6 PFU/0.5cm³ each). Virus titers in plasma ranged from 10^3.6 to 10^6.5 PFU/ml, exceeding the threshold needed to infect Culex quinquefasciatus mosquitoes (10⁵ PFU/ml). Thus, alligators may serve as a vertebrate amplifying host for WNV.

In October 2002, West Nile virus (WNV) was identified in farmed American alligators (Alligator mississippiensis) in Florida showing clinical signs and having microscopic lesions indicative of central nervous system disease. To perform seroepidemiologic studies, an indirect enzyme-linked immunosorbent assay (ELISA) was developed to determine exposure of captive and wild alligators to WNV. To validate the test, a group of WNV-seropositive and -seronegative alligators were identified at the affected farm using hemagglutination inhibition (HAI) and the plaque reduction neutralization test (PRNT). The indirect ELISA utilized a rabbit anti-alligator immunoglobulins polyclonal antibody as the secondary antibody, and inactivated WNV-infected Vero cells were used as the coating antigen. For all samples (n=58), the results of the ELISA were consistent with the HAI and PRNT findings. Plasma was collected from 669 free-ranging alligators from 21 sites across Florida in April and October 2003. Four samples collected in April and six in October were positive for WNV antibodies using HAI, PRNT, and the indirect ELISA. This indicated that wild alligators in Florida have been exposed to WNV. These findings can be used as a baseline for future surveys.

The prevalence of infection of Columbian black-tailed deer (Odocoileus hemionus columbianus) with Borrelia spp. was evaluated in an area of northwestern California (USA) where Lyme disease is endemic and the relapsing-fever group spirochete Borrelia coriaceae is enzootic, and in a far-removed comparison area having a disparate climate and lower density of vector ticks. Blood samples collected from both deer herds in 1987, 1988, and from 2000–02 were assayed for borrelial infection with microscopic and molecular methods. Serum specimens from two (5%) of 39 deer from the Dye Creek Preserve in Tehama County versus 13 (20%) of 64 animals from the Hopland Research and Extension Center (HREC) in Mendocino County, California were polymerase chain reaction (PCR) test positive for B. burgdorferi sensu lato. DNA sequencing analyses revealed that eight animals were infected with B. bissettii, six with three unclassified genotypes, and one with B. burgdorferi sensu stricto. One serum sample (2%) from HREC was positive for a relapsing-fever group spirochete that had a 16S rRNA sequence homology of 99% with the C053 type strain of B. coriaceae. Spirochetes undetermined to genospecies were detected in thick-blood drops prepared from three (8%) of 36 deer from the HREC by direct immunofluorescence. Adults of the hippoboscid flies Lipoptena depressa (n=73) and Neolipoptena ferrisi (n=24), the Pacific Coast tick (Dermacentor occidentalis) (n=22), and the western black-legged tick (Ixodes pacificus) (n=1) that had been removed from deer from both study areas in 2002 were PCR test negative for borreliae. The occurrence of diverse borreliae in deer from northern California confounds and, consequently, reduces the utility of borrelial serosurveys for detecting specific genospecies, unless they are complemented by more specific assays (e.g., immunoblotting, PCR/sequencing analysis).

A survey for Brucella spp. antibodies was undertaken on 164 serum samples from 144 Hawaiian monk seals (Monachus schauinslandi) from the northwestern Hawaiian Islands collected between 1995 and 2002. The buffered antigen plate agglutination test (BPAT), the indirect enzyme immunoassay (I-ELISA), the competitive enzyme immunoassay (C-ELISA), and the fluorescence polarization assay (FPA) were compared with regard to their ability in detecting antibodies to Brucella spp. in the serum samples. Overall, antibodies were detected in 28 (17.1%) animals, using the BPAT test, 25 (15.2%) by the C-ELISA, and 19 (11.6%) in the I-ELISA and the FPA test, using thresholds established for cattle. No evidence of gross pathology consistent with clinical brucellosis was noted in any of the seropositive animals tested. Although further work would be necessary to validate these tests for use with monk seals it appears that both the C-ELISA and the FPA tests would be appropriate as diagnostic screening tests for detection of antibodies to Brucella spp. in this species.

Mortality from cerebrospinal parelaphostrongylosis caused by the meningeal worm (Parelaphostrongylus tenuis) has been hypothesized to limit elk (Cervus elaphus nelsoni) populations in areas where elk are conspecific with white-tailed deer (Odocoileus virginianus). Elk were reintroduced into Michigan (USA) in the early 1900s and subsequently greatly increased population size and distribution despite sympatric high-density (≥12/km²) white-tailed deer populations. We monitored 100 radio-collared elk of all age and sex classes from 1981–94, during which time we documented 76 mortalities. Meningeal worm was a minor mortality factor for elk in Michigan and accounted for only 3% of mortalities, fewer than legal harvest (58%), illegal kills (22%), other diseases (7%), and malnutrition (4%). Across years, annual cause-specific mortality rates due to cerebrospinal parelaphostrongylosis were 0.033 (SE=0.006), 0.029 (SE=0.005), 0.000 (SE=0.000), and 0.000 (SE=0.000) for calves, 1-yr-old, 2-yr-old, and ≥3-yr-old, respectively. The overall population-level mortality rate due to cerebrospinal parelaphostrongylosis was 0.009 (SE=0.001). Thus, meningeal worm had little impact on elk in Michigan during our study despite greater than normal precipitation (favoring gastropods) and record (≥14 km²) deer densities. Further, elk in Michigan have shown sustained population rates-of-increase of ≥18%/yr and among the highest levels of juvenile production and survival recorded for elk in North America, indicating that elk can persist in areas with meningeal worm at high levels of population productivity. It is likely that local ecologic characteristics among elk, white-tailed deer, and gastropods, and degree of exposure, age of elk, individual and population experience with meningeal worm, overall population vigor, and moisture determine the effects of meningeal worm on elk populations.

Two experiments were conducted to examine the interactive effects of two disease agents of wild turkeys (Meleagris gallopavo), turkeypox virus and the malarial organism, Plasmodium hermani, on the health of turkey poults. Groups of domestic broad-breasted white turkey poults of 1 and 10 wk of age were infected with either turkeypox virus, P. hermani, both turkeypox virus and P. hermani, or were maintained as uninfected controls. The strains of turkeypox virus and P. hermani had been isolated from wild turkeys in southern Florida (USA). The goals of these experiments were two-fold and included both an examination of age differences in response to infections, and an examination of the effects of dual versus singular infections with the two agents. Both singular and concomitant infections of turkeypox virus and P. hermani were more detrimental to poults infected at 1 wk of age than to those infected at 10 wk, based on mortality, weight gain, and parasitemia. Dual infections of turkeypox virus and P. hermani were found to be slightly more harmful to 1-wk-old poults than were singular infections. No such interactive effects were noted in the poults infected at 10 wk of age.

Saiga antelope (Saiga tatarica) graze extensively on livestock pasture, potentially enabling transmission of a wide range of parasitic helminths between saigas and domestic ruminants. Thirty-six of the 38 species of helminth that have been found in saigas in Kazakhstan in the past have been found also in domestic livestock. We examined 133 saigas culled for meat in autumn 1997, and found three species of cestode and 12 nematodes (nine in the abomasum), but no trematodes or lungworms. The most abundant species were Marshallagia marshalli, Marshallagia mongolica, and Nematodirus gazellae in the abomasum, Nematodirus gazellae in the small intestine, and Skrjabinema ovis in the large intestine. There was no clear relationship between intensities of abomasal nematodes and body condition. Age-intensity patterns differed between species: N. gazellae intensities were highest in saigas around 2–3 yr old, and declined in older animals, whereas the intensity of Marshallagia spp. rose asymptotically with age. Fecal egg density was directly proportional to adult worm intensity across ages for Marshallagia spp., but only in young animals for N. gazellae. There was no evidence that helminths, at the intensities observed, adversely affect saiga populations. The host range of many of the parasites found is broad, and transmission between saigas and livestock in both directions might become important to agriculture and conservation as livestock numbers recover. Simplified sampling techniques used in this study, and statistical analysis based on bootstrapping, could prove useful in other parasitologic surveys of wildlife in remote areas.

Attempts were made to reproduce avian vacuolar myelinopathy (AVM) in a number of test animals in order to determine the source of the causative agent for birds and to find a suitable animal model for future studies. Submerged vegetation, plankton, invertebrates, forage fish, and sediments were collected from three lakes with ongoing outbreaks of AVM and fed to American coots (Fulica americana), mallard ducks and ducklings (Anas platyrhynchos), quail (Coturnix japonica), and laboratory mice either via gavage or ad libitum. Tissues from AVM-affected coots with brain lesions were fed to ducklings, kestrels (Falco sparverius), and American crows (Corvus brachyrhynchos). Two mallards that ingested one sample of Hydrilla verticillata along with any biotic or abiotic material associated with its external surface developed brain lesions consistent with AVM, although neither of the ducks had clinical signs of disease. Ingestion of numerous other samples of Hydrilla from the AVM affected lakes and a lake with no prior history of AVM, other materials (sediments, algae, fish, invertebrates, and water from affected lakes), or tissues from AVM-affected birds did not produce either clinical signs or brain lesions in any of the other test animals in our studies. These results suggest that waterbirds are most likely exposed to the causative agent of AVM while feeding on aquatic vegetation, but we do not believe the vegetation itself is the agent. We hypothesize that the causative agent of AVM might either be accumulated by aquatic vegetation, such as Hydrilla, or associated with biotic or abiotic material on its external surfaces. In support of that hypothesis, two coots that ingested Hydrilla sampled from a lake with an ongoing AVM outbreak in wild birds developed neurologic signs within 9 days (ataxia, limb weakness, and incoordination), and one of two coots that ingested Hydrilla collected from the same site 13 days later became sick and died within 38 days. None of these three sick coots had definitive brain lesions consistent with AVM by light microscopy, but they had no gross or histologic lesions in other tissues. It is unclear if these birds died of AVM. Perhaps they did not ingest a dose sufficient to produce brain lesions or the lesions were ultrastructural. Alternatively, it is possible that a separate neurotoxic agent is responsible for the morbidity and mortality observed in these coots.

Winter severity is a primary factor influencing deer survival and reproduction in northern climates. Prolonged, harsh winters can adversely affect body condition of does, resulting in depressed morphologic development of neonates. In this study, we captured 59 white-tailed deer (Odocoileus virginianus) neonates (28 in 2001 and 31 in 2002), following two distinctly different winters, one severe and the other historically mild. Vaginal implant transmitters allowed exact age to be determined for 73% of the neonates; new hoof growth was used to estimate age (days) of the other 27%. Birthdate and morphologic measurements of neonates (i.e., birth mass, new hoof growth, hoof length) were compared by sex and capture year. For known-age neonates (n=43), there was a year-by-sex interaction effect (P=0.01) on birthdate, being later for females during spring 2001 compared with 2002, which was consistent with a significant (P=0.03) year-by-sex interaction for total hoof length (22.3 mm [SE=0.9] and 20.3 [SE=0.8] for females and males in 2001; 19.9 [SE=1.0] and 22.1 [SE=1.0] for females and males in 2002). Interestingly, there was no effect of year on birth mass or birthdate of known-age neonates. A year-by-sex interaction (P=0.04) was determined for birthdates of estimated age (≤ days) neonates (n=16), with females born earlier than males in 2001 and later than males in 2002. Dam age had an apparent effect on birthdates of known-age neonates, as fawns born to dams ≤5 yr old were born later (P=0.01) than fawns born to dams >5 yr old (2 June and 26 May, respectively). Capture year had little effect on 20 hematologic and serum characteristics examined; however, there were significant (P<0.05) sex effects on red blood cell (RBC) counts, serum cholesterol, and cortisol concentrations, and a year-by-sex effect (P=0.04) on triglycerides. Mean corpuscular volume (MCV) was the only blood characteristic that differed (P<0.01) between years, with higher values occurring in spring 2001. We report a range of reference values for blood constituents that have not been previously documented for free-ranging neonates. Overall, winter severity appeared to have little effect on birth, morphologic, or blood characteristics of neonates. Documenting reference values for free-ranging, known-age neonates is of particular importance to enhancing our understanding of their rapid physiologic development, the concomitant changes in mean values of their blood constituents, and the natural variability that appears to be associated with those values. Our findings suggest caution should be exercised when applying physiologic models derived in captivity to free-ranging deer populations.

B-esterases are serine hydrolases composed of cholinesterases, including acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), and carboxylesterase (CbE). These esterases, found in blood plasma, are inhibited by organophosphorus (OP) and carbamate (CB) insecticides and can be used as nondestructive biomarkers of exposure to anticholinesterase insecticides. Furthermore, B-esterases are involved in detoxification of these insecticides. In order to establish the level of these enzymes and to have reference values for their normal activities, total plasma cholinesterase (ChE), AChE and BChE activities, and plasma CbE activity were determined in 729 European raptors representing 20 species, four families, and two orders. The diurnal families of the Falconiforme order were represented by Accipitridae and Falconidae and the nocturnal families of the Strigiforme order by Tytonidae and Strigidae. Intraspecies differences in cholinesterase activities according to sex and/or age were investigated in buzzards (Buteo buteo), sparrowhawks (Accipiter nisus), kestrels (Falco tinnunculus), barn owls (Tyto alba), and tawny owls (Strix aluco).Sex-related differences affecting ChE and AChE activities were observed in young kestrels (2–3-mo-old) and age-related differences in kestrels (ChE and AChE), sparrowhawks (AChE), and tawny owls (ChE, AChE, and BChE). The interspecies analysis yielded a negative correlation between ChE activity and body mass taking into account the relative contribution of AChE and BChE to ChE activity, with the exception of the honey buzzard (Pernis apivorus). The lowest ChE activities were found in the two largest species, Bonelli's eagle (Hieraaëtus fasciatus) and Egyptian vulture (Neophron percnopterus) belonging to the Accipitridae family. The highest ChE activities were found in the relatively small species belonging to the Tytonidae and Strigidae families and in honey buzzard of the Accipitridae family. Species of the Accipitridae, Tytonidae, and Strigidae families were characterized by a BChE contribution that dominated the total ChE activity, while in the species of the Falconidae family, AChE activity dominated. With the exception of the barn owl, CbE activity (eserine-insensitive α-naphthyl acetate esterase [α-NAE] activity) in all species was almost absent or very low. The values obtained in this study for ChE, AChE, and BChE activities and the AChE:BChE ratios for buzzard, kestrel, barn owl, and tawny owl provide a good estimate of the normal values in free-living individuals of these European species. They can be used as a baseline to evaluate the effect of anticholinesterase insecticides in the field.

Study of amphibian immunotoxicology is a growing area of research, but very little information is available on how environmental contaminants affect disease resistance in urodele amphibians. Urodele amphibians lack the more highly evolved aspects of the specific immune system that are present in anurans, birds, and mammals. Instead, these animals rely more heavily on innate defense mechanisms than do anurans to provide rapid, nonspecific protection from pathogens. Thus, it is prudent that immunotoxicologic research with urodele amphibians includes an evaluation of effects of contaminant exposure on nonspecific immunity. The objectives of this study were to measure the phagocytic and oxidative-burst activity of peritoneal neutrophils collected from a urodele, the tiger salamander (Ambystoma tigrinum),and to evaluate the use of these assays in immunotoxicologic research using urodele amphibians. Using tiger salamanders collected in August 2000, phagocytosis and oxidative-burst assays modified from mammalian protocols were conducted through October 2001. Results indicated that large numbers of peritoneal neutrophils for use in immunotoxicologic tests can be collected from salamanders injected with thioglycollate. Moreover, these neutrophils readily engulfed foreign material (phagocytic activity) and produced measurable amounts of hydrogen peroxide (oxidative-burst activity). Phagocytosis was effectively inhibited by incubating cells with sodium azide (P<0.001), and quantification of phagocytosis using flow cytometry was well correlated with manual counts (r=0.84, P<0.001). Dexamethasone treatment reduced phagocytic activity as measured by manual counts (P<0.02), suggesting that this test is useful for detecting alteration by immunosuppressive agents. In contrast, oxidative function was unaffected by dexamethasone treatment, and results from the oxidative-burst assay were generally less consistent than those from the phagocytosis assay. Based on these results, phagocytic activity of peritoneal neutrophils may be a useful endpoint in immunotoxicologic studies to evaluate the impact of environmental contaminants on innate defense mechanisms in urodele amphibians.

Zinc phosphide (Zn₃P₂) is a rodenticide used to control a variety of small mammal species. It is available over-the-counter or as a restricted-use pesticide depending on how it is to be applied. The toxicity of Zn₃P₂ is dependent on the species exposed, whether the animal is able to vomit or not, and whether it is ingested on a full or empty stomach. Nontarget species can be exposed through inadvertent or intentional product misapplication. In this article we describe four mortality events in which wild turkeys (Meleagris gallopavo) were believed to have been intoxicated following the ingestion of baits containing Zn₃P₂.

A free-ranging juvenile fisher (Martes pennanti) with ataxia, lethargy, stupor, and intermittent, whole-body tremors was examined postmortem. Microscopically, the fisher had protozoal meningoencephalitis caused by Sarcocystis neurona, which was confirmed by immunohistochemistry, polymerase chain reaction (PCR) and restriction fragment length polymorphism testing, and genetic sequencing. Sarcocysts found in the skeletal muscle of the fisher were negative for S. neurona by PCR, but were morphologically similar to previous light and electron microscopy descriptions of S. neurona. This is the first report of clinical neural S. neurona infection in a fisher.

To assess if wild carnivores in Germany play a role in the epizootiology of canine parvovirus (CPV) infection, seroprevalences against CPV in free-ranging carnivores (n=1,496) from selected urban and rural areas were compared. Antibodies against CPV were found in sera from red foxes (Vulpes vulpes; 136 of 1,442; 9%), raccoon dogs (Nyctereutes procyonides; two of 33; 6%), stone martens (Martes foina; four of 13; 31%), and pine martens (Martes martes; one of two) using the hemagglutination-inhibition test and pig erythrocytes. Evidence of CPV infection was detected in all study areas. Antibody titers varied between 10 and 320. In red foxes, the number of reactors did not differ between most urban and rural areas. However, we found significantly more reactors in the most densely populated urban area (Berlin). None of 430 tissue samples (small intestine, spleen, mesenterial lymph nodes) from any species tested for the presence of CPV nucleic acid using polymerase chain reaction yielded an amplification product. Based on our results, we believe that contact between domestic dogs and free-ranging red foxes probably plays a subordinate role in the epizootiology of CPV in Germany.

Avian polyomavirus (APV) infection of recently imported Crimson's seedcrackers (Pyrenestes sanguineus) resulted in mortality in 56 of 70 (80%) birds in January 2000. Viral infection in these birds was characterized by diarrhea, anorexia, and lethargy, and death usually ensued within 48 to 72 hr of initial clinical signs. Bacteriologic testing resulted in consistently negative results. Histologic examination of tissues from dead birds revealed large intranuclear inclusion bodies, which at electron microscopy examination, contained 42- to 49-nm viral particles. The diagnosis of APV infection was based on immunohistochemistry and immunoelectronmicroscopy, using a monoclonal antibody specific for VP-1 major capsidic APV protein. This is the first report of an acute APV outbreak in wild, recently imported, Crimson's seedcrackers.

Upper respiratory tract disease (URTD) has been associated with major losses of free-ranging desert tortoises (Gopherus agassizii) in the southwestern United States. This prompted a clinical examination of 68 free-ranging desert tortoises for signs of URTD and sampling for Mycoplasma agassizii, the causative agent of URTD. Tortoises were sampled from three sites in the eastern Mojave Desert (1992–93) and from three sites in the Sonoran Desert (1992–94). Plasma was analyzed for antibodies to M. agassizii using an enzyme-linked immunosorbent assay (ELISA). Nasal aspirate from 12 Sonoran tortoises was tested using polymerase chain reaction (PCR) test to detect the 16S rRNA gene of M. agassizii. Nasal aspirate from all tortoises was cultured for Mycoplasma sp. In the Mojave Desert, nine tortoises had clinical signs of URTD (n=28). Eight of the nine tortoises with clinical signs were seropositive for M. agassizii. In the Sonoran Desert, there were no clinical signs of URTD, but two tortoises were seropositive (n=40), and two tortoises had PCR results indicating presence of M. agassizii (n=12). Monitoring of URTD is recommended for Mojave tortoises, and further monitoring is needed for Sonoran tortoises because we do not know the extent of this disease in this population.

Eastern equine encephalitis (EEE) was diagnosed in a free-ranging, adult, male white-tailed deer (Odocoileus virginianus) from Houston County, Georgia, USA, in July 2001. The yearling buck had neurologic disease and died during transport to our diagnostic facility. Eastern equine encephalitis virus (EEEV) was isolated in Vero cell culture and identified by reverse-transcriptase polymerase chain reaction; as well, EEEV antigen was detected in brain by immunohistochemistry. This is the first report of fatal EEEV infection in a white-tailed deer. Antibodies to EEEV were demonstrated by microtiter neutralization in 14 of 99 (14%) of the white-tailed deer from Georgia sampled in fall 2001. Most antibody-positive deer originated from the Coastal Plain physiographic region. Eastern equine encephalitis virus should be considered a possible cause of neurologic disease in white-tailed deer where it may occur.

A 3-yr-old male white-tailed deer (Odocoileus virginianus) with a history of ataxia and tremors was submitted to the Tifton Veterinary Diagnostic and Investigational Laboratory (The University of Georgia, Tifton, Georgia, USA) for necropsy. Gross findings were unremarkable. Histologically, the brain had multifocal lymphoplasmacytic perivascular inflammation, scattered gliosis, and rare satellitosis. Mild hemorrhage and congestion in the retropharyngeal lymph nodes and mild lymphoid depletion in the tonsil were present. A reverse transcription–polymerase chain reaction test performed on brain yielded a positive result for West Nile virus. This represents the first report of fatal West Nile virus infection in a white-tailed deer.

Numbers of the endangered Key Largo woodrat (KLWR; Neotoma floridana smalli) have been declining for at least 25 yr. The raccoon (Procyon lotor) roundworm, Baylisascaris procyonis, has been found to have an adverse effect on the survival of Alleghany woodrats (N. magister). High densities of raccoons can exacerbate this problem by increasing the amount of feces containing viable eggs of B. procyonis available to woodrats. In 2002, 64 fecal samples were collected and examined for eggs of B. procyonis from >32 raccoons within the KLWR's known range on Key Largo, Florida, USA. All samples were negative for eggs of B. procyonis. Raccoon density in this area was approximately 0.62 raccoons/ha. Despite this high density of raccoons, B. procyonis does not appear to be a threat to the KLWR population.

Six weak whooper swans (Cygnus cygnus) and two weak tundra swans (Cygnus columbianus) were found at Swamp Miyajima (Hokkaido, Japan) in May 1998. Anorexia, depression, green watery feces, pale conjunctiva, and anemia were observed. Radiographs showed from six to 38 suspected lead pellets in the gizzard. Blood lead concentrations were 2.5–6.7 μg/g (mean±SD=4.6±1.14 μg/g) on day 1. After blood collection, the birds were treated with calcium disodium ethylenediaminetetraacetate (CaEDTA) given intravenously and force fed. Despite treatment, seven birds died the next day. Green, bile-stained livers and pale or green kidneys were observed on necropsy. Microscopically, bile pigment was widespread in the liver and acid-fast intranuclear inclusion bodies were observed in renal tubular epithelium. Lead concentrations in livers and kidneys were 14.0–30.4 μg/g and 30.2–122 μg/g wet weight, respectively. Only one bird survived and this whooper swan continued to be treated with CaEDTA and activated charcoal. No lead shot was observed in the proventriculus and gizzard by radiography on day 64 and the blood lead concentration decreased from 2.9 μg/g to 0.09 μg/g during that same period. After 4 mo of rehabilitation, the whooper swan was returned to the wild. Lead intoxication continues to be a problem at Swamp Miyajima.

We identified Echinococcus multilocularis for the first time in brown lemmings (Lemmus trimucronatus) from Barrow, Alaska, USA. Of 467 brown lemmings trapped between 1995 and 2000, two males and two females (0.9%; 95% confidence interval = 0.9±0.9%) were found to be infected with metacestodes of E. multilocularis. No metacestodes were found in 17 collared lemmings (Dicrostonyx rubricatus) also trapped at Barrow. In humans, E. multilocularis causes alveolar echinococcosis, which is potentially fatal. Knowledge of the distribution of this parasite is important to protect the public health.