This paper reviews 22 published field studies that have found an association between exposure to environmental contaminants and alterations in thyroid gland structure, circulating thyroid hormones and vitamin A (retinoid) status in free-ranging populations of wildlife and fish. Vitamin A and thyroid hormones play critical roles during development, growth and function throughout life. Studies of captive wildlife and laboratory studies support a relationship between alterations in thyroid hormones and vitamin A status and exposure to dioxins, furans, and planar polychlorinated biphenyls, which bind to the aryl hydrocarbon receptor. Some studies have found adverse health effects in wildlife associated with exposure to polyhalogenated aromatic hydrocarbons and altered thyroid and retinoid status including: decreased reproductive success, immune system changes, dermatologic abnormalities and developmental deformities. A direct causal relationship between these effects and thyroid and retinoid changes has not been demonstrated. Field researchers studying the responses to these synthetic chemicals in wildlife and fish should include measurement of thyroid hormones and retinoids and histological examination of the thyroid gland in their study design as biomarkers of exposure to these chemicals in the environment.

Land-treatment of petroleum wastes is a widely used industrial practice, yet there has been no comprehensive evaluation of the long-term risks to human or terrestrial ecosystems from such practices. We evaluated cotton rat (Sigmodon hispidus) populations on three sites in Oklahoma (USA) that historically used land-treatment for disposal of various petroleum wastes (July 1995–March 1997). Average concentrations of fluoride in soil from these sites ranged from 878 to 4317 mg/kg. A census of resident cotton rats on land-treatment sites revealed a high incidence (40% overall) of dental lesions compared to reference populations (<1% dental lesions). During winter there was a 34% to 65% increase compared to summer in frequency of dental lesions in cotton rats on two of the three land-treatment sites. Incidence of dental lesions on two land-treatment sites was greater (9–16%) in female cotton rats compared to males. Cotton rats from land-treatment sites had higher concentrations of fluoride in bone and greater severity of dental lesions compared to reference animals. Dental lesions were considered to be most consistent with dental fluorosis because of elevated fluoride in bone. Neither concentration of fluoride in soil nor level of fluoride in bone was a good predictor of severity of dental lesions in cotton rats on land-treatment sites.

Body composition was measured in male American kestrels (Falco sparverius) beginning after a 77-day exposure to 0, 6, or 12 ppm (dry wt.) selenium as seleno-L-methionine in their diet. Total body mass, lean body mass, and body fat were compared among groups to identify potential wasting effects of selenium, as had been reported for wild waterfowl from a selenium-contaminated site. On the last day of selenium treatment, selenium concentrations in the blood of kestrels was significantly negatively correlated with lean mass. Kestrels that had been exposed to 12 ppm selenium in the diet exhibited relatively higher lean mass (relative to total body mass) and lower normalized body fat than kestrels fed 0 or 6 ppm dietary selenium. These differences persisted throughout the 6 mo study period. The effect observed on body condition of kestrels at environmentally relevant exposure levels has implications for wild birds with respect to both overwinter survival and reproductive success.

A pharmacokinetic and tissue residue study was conducted to assess the risks associated with human consumption of polar bears in arctic Canada that have been exposed to the immobilizing drug Telazol®, a mixture of tiletamine hydrochloride and zolazepam hydrochloride. Twenty-two bears were remotely injected with about 10 mg/kg of Telazol®. Following immobilization, serum samples were collected serially at regular intervals until the bears awakened. Sixteen of the bears were relocated and killed under permit by local hunters at various times from 0.5 to 11 days after dosing. Serum, kidney, muscle and adipose tissue samples were collected immediately after death. All samples were stored at -70 C until analysis by HPLC. The concentration-time data of tiletamine and zolazepam in serum during the immobilization period were fitted to curves by computer and the pharmacokinetic parameters assessed. In addition, the serum and tissue samples collected at the time of death were analyzed for both parent drugs, for one metabolite of tiletamine (CI-398), and for three metabolites of zolazepam (metabolites 1, 2 and 4). A one-compartment model with first-order absorption and elimination best fit the time-series data for the drugs in serum during the immobilization period. This model gave half-lives (mean ± SE) for tiletamine and zolazepam of 1.8 ± 0.2 h and 1.2 ± 0.08 h, respectively, clearance values of 2.1 ± 0.3 1 h^-1·kg^-1 and 1.1 ± 0.1 1·h^-1·kg^-1, and volumes of distribution of 5.2 ± 0.6 1/kg and 1.8 ± 0.2 1/kg. The concentrations of both drugs and their metabolites declined rapidly to trace levels by 24 h post-dosing, although extremely low concentrations of some metabolites were encountered sporadically over the entire sampling period. In particular, zolazepam metabolite 2, remained detectable in fat and muscle tissue at the end of the study, 11 days after dosing. It was concluded that during immobilization, both tiletamine and zolazepam levels decline rapidly in a monoexponential fashion, and their pharmacokinetic parameters in polar bears are similar to those observed in other species. Tissue levels of the drugs and their metabolites declined sufficiently rapidly that individuals eating meat from exposed bears would be unlikely to experience pharmacological effects from the drugs. Nevertheless, slight exposure to the drugs and/or their metabolites might be possible for an indeterminate time after dosing.

Sixty chemical immobilizations of red deer (Cervus elaphus hippelaphus) have been carried out during an etho-ecological study from August 1994 to December 1996 in a 35 ha pen in the district of Nitra (Slovac Republic). Our objective was to determine the efficacy and standard dosages of Zoletil® and Rompun® for the immobilization of adult red deer in feral conditions as an alternative to the use of the highly toxic opioids. We therefore compared an Immobilon®-Rompun® combination (ImRo) with a 1:1 mixture of Zoletil® and Rompun® (ZoRo) as an injectable solution. Use of both combinations led to the immobilization of >92% of deer with an injection volume <3 ml. Mean (SD) dose to achieve immobilization was 35 (14) μg/kg ethorphine 0.14 (0.056) mg/kg acepromazine 0.36 (0.14) mg/kg xylazine compared to 1.2 (0.8) mg/kg tiletamine 1.2 (0.8) mg/kg zolazepam 2.3 (1.6) mg/kg xylazine. This corresponds to a volume of 1.8 (0.7) ml/100 kg body mass (BM) for ImRo (range = 1.0 to 4.6) and to 2.3 (1.6) ml/100 kg BM for ZoRo (range = 0.7 to 4.0), respectively. Heart rate, respiratory rate and oxyhaemoglobin saturation values did not differ significantly between the two groups during immobilization. Three deer (5%) died during immobilization, but fatalities could not be directly associated with the drug effect. Mean (SD) time from darting to complete immobilization was 5.5 (4.2) min for ImRo and 7.5 (6.1) min for ZoRo, respectively. Differences were not statistically significant. Anesthesia with both combinations of immobilizing agents could be reversed within 2 min using sarmazenile-yohimbine for ZoRo and diprenorphine-yohimbine for ImXy immobilizations, respectively. We conclude that the 1:1 combination of Zoletil® and xylazine is a valuable alternative to the use of opioids for the immobilization of adult red deer including feral adult animals.

Thirty two free-ranging female white-tailed deer (Odocoileus virginianus) were anesthesized with varying Telazol® and xylazine HCl combinations in Front Royal (Virginia, USA) between August 1992 and September 1992. All animals were caught in baited box traps, manually restrained, and hand injected with a combination of Telazol and xylazine administered intramuscularly. Deer received mean ± SE dosages of 2.53 ± 0.16 mg/kg Telazol and 0.69 ± 0.05 mg/kg of xylazine. These dosages achieved a rapid and effective anesthetic plane for short-term procedures such as weighing, blood collection, and translocation. Eight of 32 deer (25%) required an intravenous (i.v.) supplement of ketamine HCl (100 mg) to maintain a safe plane of anesthesia. Ketamine supplementation provided an average of 11.8 ± 2.0 min additional safe handling. Satisfactory reversals were achieved in all deer by administering yohimbine HCl 16 mg i.v. (dose range, 0.22 to 0.48 mg/kg) to all animals.

Surveillance and epidemic modeling were used to study chronic wasting disease (CWD), a transmissible spongiform encephalopathy that occurs naturally among sympatric, free-ranging deer (Odocoileus spp.) and Rocky Mountain elk (Cervus elaphus nelsoni) populations in contiguous portions of northeastern Colorado and southeastern Wyoming (USA). We used clinical case submissions to identify endemic areas, then used immunohistochemistry to detect CWD-infected individuals among 5,513 deer and elk sampled via geographically-focused random surveys. Estimated overall prevalence (prevalence, 95% confidence interval) in mule deer (4.9%, 4.1 to 5.7%) was higher than in white-tailed deer (2.1%, 0.5 to 3.4%) or elk (0.5%, 0.001 to 1%) in endemic areas; CWD was not detected in outlying portions of either state. Within species, CWD prevalence varied widely among biologically- or geographically-segregated subpopulations within the 38,137 km² endemic area but appeared stable over a 3-yr period. The number of clinical CWD cases submitted from an area was a poor predictor of local CWD prevalence, and prevalence was typically ≥1% before clinical cases were first detected in most areas. Under plausible transmission assumptions that mimicked field data, prevalence in epidemic models reached about 1% in 15 to 20 yr and about 15% in 37 to 50 yr. Models forecast population declines once prevalence exceeded about 5%. Both field and model data supported the importance of lateral transmission in CWD dynamics. Based on prevalence, spatial distribution, and modeling, we suggest CWD has been occurring in northeastern Colorado and southeastern Wyoming for >30 yr, and may be best represented as an epizootic with a protracted time-scale.

Diseased animals may exhibit behavioral shifts that increase or decrease their probability of being randomly sampled. In harvest-based sampling approaches, animal movements, changes in habitat utilization, changes in breeding behaviors during harvest periods, or differential susceptibility to harvest via behaviors like hiding or decreased sensitivity to stimuli may result in a non-random sample that biases prevalence estimates. We present a method that can be used to determine whether bias exists in prevalence estimates from harvest samples. Using data from harvested mule deer (Odocoileus hemionus) sampled in northcentral Colorado (USA) during fall hunting seasons 1996–98 and Akaike's information criterion (AIC) model selection, we detected within-yr trends indicating potential bias in harvest-based prevalence estimates for chronic wasting disease (CWD). The proportion of CWD-positive deer harvested slightly increased through time within a yr. We speculate that differential susceptibility to harvest or breeding season movements may explain the positive trend in proportion of CWD-positive deer harvested during fall hunting seasons. Detection of bias may provide information about temporal patterns of a disease, suggest biological hypotheses that could further understanding of a disease, or provide wildlife managers with information about when diseased animals are more or less likely to be harvested. Although AIC model selection can be useful for detecting bias in data, it has limited utility in determining underlying causes of bias. In cases where bias is detected in data using such model selection methods, then design-based methods (i.e., experimental manipulation) may be necessary to assign causality.

Handling mortality and recapture rates of wild rodents that were bled from the retro-orbital capillary plexus without anesthesia were assessed. In 9,670 captures of seven species of rodents from 1994 through 1998, we found no difference in handling mortality in bled mice compared to those from trapping grids where mice were not bled. Recapture rates of rodents on control (non-bleeding grids) and rodents on bleeding grids was not significantly different for any species. We conclude that bleeding in the absence of anesthesia does not affect immediate mortality or subsequent recapture.

Antibodies reactive with Ehrlichia chaffeensis were detected in raccoon (Procyon lotor) serum samples by using an indirect immunofluorescence assay. Samples from 411 raccoons trapped in the southeastern United States from 1977 to 1999 were tested. Serologically reactive samples with reciprocal titers of ≥16 were detected from 83 raccoons (20%) from 13 of 16 counties in eight states, indicating that raccoons are commonly exposed to E. chaffeensis. Samples collected as early as 1977 were positive. A polymerase chain reaction assay specific for E. chaffeensis failed to detect the presence of ehrlichial DNA in serum samples from 20 representative seroreactive raccoons. Because of serologic cross-reactivity among antigens derived from different Ehrlichia spp., additional immunologic, molecular, or culture-based studies will be required to confirm E. chaffeensis infections of raccoons in the southeastern United States.

Molecular genetics was used to devise the first reliable diagnostic tool for differentiating morphologically indistinguishable dorsal-spined, first-stage larvae (L1's) and other stages of the nematode protostrongylid subfamily Elaphostrongylinae. A polymerase chain reaction (PCR) assay employing specifically designed primers was developed to selectively amplify DNA of the ITS-2 region of the ribosomal gene. Amplification of the entire ITS-2 region differentiated between larvae of the genera Elaphostrongylus and Parelaphostrongylus, based on the lengths of fragments produced. Three sets of primers were designed and used successfully to distinguish larvae at the species level. Although it was demonstrated that one primer set in a single PCR assay was capable of distinguishing each of the three Parelaphostrongylus spp., a second primer set would be required for confirmation in routine diagnostic use. Two of the three primer sets were capable of amplifying DNA from all six elaphostrongyline species and of identifying Elaphostrongylus alces and Parelaphostrongylus odocoilei. Although two separate fragments were produced from each Elaphostrongylus cervi and Elaphostrongylus rangiferi, it was not possible to distinguish these two parasites from each other based on the fragment size. The use of various nematodes, hosts, and fecal controls demonstrated the reliability of the primers for all developmental stages including L1's, third-stage larvae, and adult worms. These primers also have potential for identifying other lungworms as was shown by the amplification of Umingmakstrongylus pallikuukensis, the muskox protostrongylid, and Dictyocaulus sp. from white-tailed deer. Although this assay may benefit from further refinement, its present design provides researchers, wildlife managers, clinicians, and animal health regulators with a practical tool for the control, management, and study of meningeal and tissue worms and their close relatives.

Island foxes (Urocyon littoralis) are endemic to six of the eight California Channel Islands (USA). The island fox is classified as a threatened species by the State of California, and recently three of the six subspecies have experienced abrupt population declines. As part of a continuing effort to determine the cause of the declines, we tested island fox serum samples collected in 1988 (n = 176) and 1997–98 (n = 156) over the entire geographic range of the species for seroprevalence of canine heartworm (Dirofilaria immitis) antigen. Using a commercially available enzyme-linked immunosorbent assay (PetChek®, Idexx Laboratories, Westbrook, Maine, USA) we detected heartworm antigen in four of the six populations of island foxes. On San Miguel and Santa Rosa Islands, seroprevalence in adult foxes was >85% (n = 62) in 1988 and increased to 100% (n = 24) in 1997–98. On Santa Cruz Island, seroprevalence in adult foxes decreased from 83% (n = 30) to 58% (n = 26), whereas on San Nicolas Island, seroprevalence increased from 25% (n = 32) to 77% (n = 30) during the same period. All of the pups assayed (n = 33) were seronegative. The seroprevalences of heartworm reported herein for the four populations of island foxes are the highest yet reported for a fox species. However, additional demographic data reported elsewhere suggests that heartworm has not been a major factor in the recent declines of island fox populations.

Two studies were conducted to determine the infectivity of the lungworm, (Dictyocaulus viviparus) of cattle origin, in Rocky Mountain elk (Cervus elaphus nelsoni) or wapiti. In the first study, each of three 9-mo-old elk was administered 3,000 D. viviparus larvae from cattle using a nasogastric tube. In the second study, four 16-mo-old elk were each inoculated with 2,000 D. viviparus from cattle using a nasogastric tube. Elk were observed daily for signs of respiratory disease, and fecal samples were collected during the studies and evaluated for lungworm larvae using a modified Baermann technique. One elk was euthanatized during the patent period for recovery of adult lungworms, and three elk were euthanatized after larvae were no longer detected in feces. Lungworm larvae were not detected before inoculation in any of the 16-mo-old elk, but were detected 22 days after inoculation in one elk, 23 days after inoculation in two elk and 24 days after inoculation in all four elk. The prepatent period of this cattle isolate of D. viviparus in elk is therefore 22 to 24 days. The precise prepatent period was not determined in the three 9-mo-old elk, but larvae were detected in all three elk 25 days after inoculation. Numbers of larvae ranged from 1/to 101/g feces with peak larval detection occurring 32 to 50 days after inoculation. Elk shed larvae from 22 to 83 days after inoculation, and patent periods of the parasite ranged from 24 to 62 days. Clinical signs of respiratory disease, with the exception of mild coughing after exercise, were not observed during the infections. Results from this experiment indicated that D. viviparus larvae of cattle origin can mature in elk and larvae can be passed in large numbers in feces, but this cattle isolate of D. viviparus was not highly pathogenic in elk.

Oral rabies vaccine-laden baits, with a tetracycline biomarker, were distributed in Pinellas County (Florida, USA) by helicopter drop and from cars from January to April 1997. A total of 130,320 baits was distributed throughout the county, yielding an average bait density of 185 baits per km². Bait ingestion was estimated by microscopic detection of tetracycline in tooth and bone samples from 244 raccoons (Procyon lotor), 33 opossums (Didelphis virginianus), 31 feral cats, and two gray foxes (Urocyon cinereoargenteus) that were trapped during February–April 1997. Active surveillance consisted of 17 trapping sites that were further categorized by six community descriptors. Passive surveillance consisted of animals that were collected as nuisance animals by Pinellas County Animal Services. The proportion of tetracycline positive raccoons was compared between collection techniques, among trapping sites, vegetation communities, and age and sex categories. Since there was no statistically significant difference in the frequency of tetracycline positive raccoons trapped during active surveillance (59%, 110/187) and passive surveillance (53%, 30/57), the data were pooled, resulting in a tetracycline positive frequency of 57% (140/244). The range in the positive tetracycline frequency established for raccoons from the 17 active surveillance sites was 9% (1/11) to 100% (3/3). The tetracycline positive frequency for raccoons ranged from 25% (3/12) at the dumpster sites to 78% (14/18) at the landfills. Juvenile male raccoons (71%, 34/48) were the most commonly marked age and sex class and adult females (42%, 21/50) were the least commonly marked age and sex class. Eighty-five percent (28/33) of the opossums, 3% (1/31) of the feral cats, and 50% (1/2) of the gray foxes were tetracycline positive.

Rabies is a widespread zoonotic disease that has reached epizootic proportions in gray foxes (Urocyon cinereoargenteus) in central Texas. Because each species of carnivore has different food preferences and foraging strategies, it is essential that the efficacy of a bait delivery program be examined for gray foxes prior to an oral vaccination program being attempted. Field trials were conducted to determine bait preferences of free-ranging gray foxes to selected baits and odor attractants. Baits consisted of polymer cubes made of either dog food meal or fish meal, and a wax-lard cake that was enhanced with marshmallow flavoring. Attractants added to baits exuded sulfurous, fatty, cheesy, or sweet odors and flavors. During 3,589 operable bait station nights, gray fox visitation and bait uptake rates were 9.2% and 8.3%, respectively. Gray foxes exhibited no preference in bait uptake rates between bait and odor attractant combinations. Gray foxes exhibited no difference in cumulative bait uptake rates between onroad and offroad sites; however, the uptake rate by raccoons was significantly greater for baits placed on roads than for baits randomly placed. Raccoons were the major non-target species competing for baits, being attributed with 73% of the total uptake. Visitation and bait uptake rates by raccoons significantly increased after a 7-day lethal removal of raccoons (n = 37) from the study area. Random distribution of baits is recommended; it reduced bait uptake by non-target species without adversely affecting uptake by gray foxes.

A 4-mo-old free-ranging Rocky Mountain bighorn sheep (Ovis canadensis canadensis) from the Hells Canyon area (Washington, USA) was diagnosed with encephalitis associated with Toxoplasma gondii infection. The sheep had concurrent pneumonic pastuerellosis and resided in a geographic area with endemic Pastuerella-associated pneumonia and mortality in bighorn sheep. The brain had multifocal necrotizing and nonsuppurative encephalitis with intralesional protozoa. The protozoa were identified as T. gondii by immunohistochemistry. To our knowledge, this is the first report of T. gondii infection in a Rocky Mountain bighorn sheep.

Acute sarcocystosis was diagnosed in an adult female wild turkey (Meleagris gallopavo) that was collected from Early County (Georgia, USA) in February of 1998. Marked inflammatory lesions were seen in the heart, lung, and liver and were associated with protozoal schizonts and merozoites. The organisms were identified as Sarcocystis sp. (Acomplexa: Sarcocystidae) based on structure and antigenicity. Protozoa divided by endopolygeny, merozoites lacked rhoptries, and the organisms did not react to anti-S. falcatula antibodies but reacted to anti-S. cruzi antibodies.

In a recent survey in Oklahoma (USA), 52 free-ranging coyotes were examined for the presence of sarcocysts. Two of these coyotes were found infected with sarcocysts in skeletal muscle. By light microscopy, the cyst wall was thin and smooth. Ultrastructurally, the cyst wall had minute villar protrusions. The sarcocysts were 14.4 to 50.4 μm wide and 46.8 to 99 μm long. This is the first report of Sarcocystis sp. sarcocysts in the skeletal muscle of coyotes.

Giardia sp. was found in the white stork (Ciconia ciconia) in The Netherlands for the first time. The Giardia sp. trophozoites that were found in the feces of a 6-wk-old white stork, were examined by light microscopy. The parasites closely resembled Giardia ardeae that had been isolated by others from several species of wading birds belonging to the order Ci-coniiformes, sharing a deeply notched adhesive disk, a single caudal flagellum, and a single round median body. Serologically, the parasites did not react with anti-Giardia intestinalis monoclonal antibodies. Although no signs of intestinal disease were observed in the stork chick, the presence of parasites in all stages of development and the huge number of parasites show that the stork chick was experiencing an active infection with G. ardeae type parasites.

Two hundred eighteen and 127 wild waterfowl (Anatidae) of five species were sampled from the Kellogg Biological Station area (Michigan, USA) during the summer (1 June to 24 August 1995) and fall (9 September to 8 October 1995), respectively. Twelve (6%) of those sampled in summer and 13 (11%) sampled in the fall were infected with hemosporids. Haemoproteus nettionis, Haemoproteus greineri, and Leucocytozoon simondi infected both summer and fall birds, with H. nettionis the most common (4% summer; 7% fall). Mean intensities were low; the highest mean intensity was 4.6 ± 1.1 gametocytes per 5,000 uninfected erythrocytes for H. nettionis in summer. Of 123 local waterfowl, none were infected with any blood parasite. Thirty-five captive year-round resident waterfowl also were sampled and no blood parasites were found.

Development of an in vitro culture system for infectious Dictyocaulus viviparus larvae made it possible to study the potential cross-transmission of D. viviparus between white-tailed deer (Odocoileus virginianus) and cattle (Bos taurus). Between 26 September 1995–29 February 1996, six parasite-free bull calves were individually inoculated with 15 to 50 infective third stage larvae (L₃)/kg of body weight cultured from adult D. viviparus collected from white-tailed deer. Three bull calves were simultaneously inoculated with 45 L₃/kg of body weight recovered from cattle either by the Baermann technique or by in vitro culture as above. All three calves inoculated with the homologous cattle strain became patently infected while all six calves inoculated with the heterologous deer strain remained negative for the presence of D. viviparus in the feces and in the lungs upon necropsy.

Elaeophorosis, caused by Elaeophora elaphi, was observed in red deer (Cervus elaphus) from Toledo Province (Spain) for the first time. Adult specimens of Elaeophora elaphi were found in the hepatic vessels of nine of 151 red deer between October 1994 and September 1995; intensity of infection was two to 18 nematodes per host. Adult nematodes were only found during the period from fall through early spring. No differences were present between sex or age groups. Parasites were not found in a limited sample from fallow deer (Dama dama). Blood samples were negative for the presence of microfilariae.

Swabs of conjunctiva were collected from 44 live and 226 hunter-harvested mule deer (Odocoileus hemionus) from Wyoming and Utah (USA). We identified 29 Gram negative and 22 Gram positive bacterial taxonomic categories, but many isolates from hunter-harvested animals were environmental contaminants. Staphylococcus spp. and Micrococcus spp. were the most common Gram positive bacteria isolated, and Enterobacter spp., Escherichia coli, and Pseudomonas spp. were common Gram negative bacteria isolated. Thelazia californiensis were found in 15% of hunter-harvested deer in Utah in 1994 and in 8% in 1995. Nematodes were found in 40% of live deer in 1995 and 66% in 1996. Three live animals showed clinical signs of infectious keratoconjunctivitis (IKC) in 1996, but pathogenic bacteria were not isolated from these individuals. Hemolytic, non-piliated Moraxella ovis was isolated from two clinically normal live deer in 1996 and isolates were similar to those cultured from IKC cases from Wyoming and Utah.

In fall 1991, a radio-collared black bear (Ursus americanus) in northern Labrador (Canada) died from valvular endocarditis caused by coagulase-positive Staphylococcus aureus, with widespread dissemination of the infection to other organs shortly before death. Apparently, this is the first reported case of bacterial valvular endocarditis in a wild black bear.

Herpesviruses are associated with several diseases of marine turtles including lung-eye-trachea disease (LETD) and gray patch disease (GPD) of green turtles (Chelonia mydas) and fibropapillomatosis (FP) of green, loggerhead (Caretta caretta), and olive ridley turtles (Lepidochelys olivacea). The stability of chelonian herpesviruses in the marine environment, which may influence transmission, has not been previously studied. In these experiments, LETD-associated herpesvirus (LETV) was used as a model chelonian herpesvirus to test viral infectivity after exposure to seawater. The LETV virus preparations grown in terrapene heart (TH-1) cells were dialyzed for 24 to 120 hr against aerated artificial or natural sea-water or Hank's balanced salt solution (HBBS). Fresh TH-1 cells were inoculated with dialyzed LETV, and on day 10 post-infection cells were scored for cytopathic effect. Virus samples dialyzed up to 120 hr were positive for the herpesvirus DNA polymerase gene by polymerase chain reaction. Electron microscopy revealed intact LETV nucleocapsids after exposure of LETV to artificial seawater or HBSS for 24 hr at 23 C. LETV preparations remained infectious as long as 120 hr in natural and artificial seawater at 23 C. Similar results were obtained with a second culturable chelonian herpesvirus, HV2245. LETV infectivity could not be detected after 48 hr exposure to artificial seawater at 30 C. Since LETV and HV2245 remain infectious for extended periods of time in the marine environment, it is possible that FP-associated and GPD-associated herpesviruses also may be stable. These findings are significant both for researchers studying the epidemiological association of herpesviruses with diseases of marine turtles and for individuals who handle turtles in marine turtle conservation efforts.

A serologic survey of swift fox (Vulpes velox) and kit fox (V. macrotis) from the western USA was conducted for 12 infectious diseases. Samples from swift fox were collected between 1987 and 1992 from Colorado (n = 44), Kansas (n = 10), and Wyoming (n = 9). Samples from kit fox were collected in California (n = 86), New Mexico (n = 18), Utah (n = 9), and Arizona (n = 6). Overall antibody prevalence rates were 33 of 110 (30%) for canine parvovirus (CPV), 9 of 72 (13%) for canine distemper virus (CDV), 23 of 117 (20%) for vesicular stomatitis New Jersey, 16 of 117 (14%) for vesicular stomatitis Indiana, six of 117 (5%) for Cache Valley virus, five of 117 (4%) for Jamestown Canyon virus, one of 97 (1%) for rabies virus, one of 117 (1%) for Colorado tick fever virus, and one of 117 (1%) for western equine encephalitis virus. In addition, antibodies were not found to Yersinia pestis, Francisella tularensis, and Borrelia burgdorferi in serum from 25 Colorado swift fox. Adult swift fox from Colorado had serologic evidence of exposure to CPV more often than juveniles. No juvenile swift fox from Colorado had serum antibodies to CDV. There were season-specific differences in serum antibody prevalence for CPV for swift fox from Colorado. No viruses were isolated from ectoparasites or fox from Colorado.