To test the hypothesis that fledging wading birds would be more at risk from mercury toxicosis than younger nestlings, captive great egret nestlings were maintained as controls or were dosed from 1- to 14-wk-old with 0.5 or 5 mg methylmercury chloride/kg wet weight in fish. Birds dosed with 5 mg/kg suffered from subacute toxicosis at wk 10–12. Growing feather concentrations were the most closely correlated with cumulative mercury consumed per weight. Blood concentrations of mercury increased more rapidly after 9 wk in all groups when feathers stopped growing. Total mercury accumulated in tissues in concentrations in the following order: growing scapular feathers > powderdown > mature scapular feathers > liver > kidney > blood > muscle > pancreas > brain > bile > fat > eye. The proportion of total mercury that was methylated depended upon tissue type and dose group. Selenium accumulated in liver in direct proportion to liver mercury concentrations. After wk 9, appetite and weight index (weight/bill length) declined significantly in both dosed groups. At current exposure levels in the Everglades (Florida, USA) mercury deposited in rapidly growing feathers may protect nestlings from adverse effects on growth until feathers cease growing.

Captive great egret (Ardea albus) nestlings were maintained as controls or were dosed with methylmercury chloride at low (0.5), and high doses (5 mg/kg, wet weight) in fish. Low dosed birds were given methylmercury at concentrations comparable to current exposure of wild birds in the Everglades (Florida, USA). When compared with controls, low dosed birds had lower packed cell volumes, dingy feathers, increased lymphocytic cuffing in a skin test, increased bone marrow cellularity, decreased bursal wall thickness, decreased thymic lobule size, fewer lymphoid aggregates in lung, increased perivascular edema in lung, and decreased phagocytized carbon in lung. High dosed birds became severely ataxic and had severe hematologic, neurologic, and histologic changes. The most severe lesions were in immune and nervous system tissues. By comparing responses in captive and wild birds, we found that sublethal effects of mercury were detected at lower levels in captive than in wild birds, probably due to the reduced sources of variation characteristic of the highly controlled laboratory study. Conversely, thresholds for more severe changes (death, disease) occurred at lower concentrations in wild birds than in captive birds, probably because wild birds were exposed to multiple stressors. Thus caution should be used in applying lowest observed effect levels between captive and wild studies.

Aflatoxins, toxic metabolites of Aspergillus flavus or Aspergillus parasiticus, cause poor feed utilization, decreased weight gains, depressed immune function, liver dysfunction, coagulation abnormalities, and death in a wide variety of species including humans. Conservationists have become concerned that increasingly popular wildlife feeding or baiting practices could expose wildlife to toxic amounts of aflatoxin-contaminated grains. In particular, the effects of aflatoxins on the wild turkey (Meleagris gallopova silvestris) are of concern because the conspecific domestic turkey is highly susceptible to aflatoxins. To evaluate the effect of dietary aflatoxin on wild turkeys, four groups of 4-mo-old wild turkeys were fed diets containing either 0, 100, 200, or 400 μg aflatoxin/kg feed for 2 wk in September and October 1996. Aflatoxin-fed poults had decreased feed consumption and weight gains as compared with control poults. Decreased liver-to-body weight ratios, liver enzyme alterations, slightly altered blood coagulation patterns, and mild histologic changes indicated low-level liver damage. Compromise of cell-mediated immunity was indicated by decreased lymphoblast transformation. The effects were apparent in all treatment groups to variable levels, but significant differences most often were found at 400 μg aflatoxin/kg feed. This study shows that short-term aflatoxin ingestion by wild turkeys can induce undesirable physiologic changes; therefore, exposure of wild turkeys to feeds containing aflatoxin levels of 100 μg aflatoxin/kg feed or more should be avoided.

Hematologic and serum chemistry values were determined for 20 adult captive European wildcats (Felis silvestris) in Lleida (Catalonia, Spain). Seven wildcats (4 females and 3 males) were captured in the wild and 13 (4 females and 9 males) were born and raised in captivity. Samples were collected between September and December from 1993 to 1998. Blood was obtained by jugular venipuncture after administration of either ketamine and xylazine or ketamine and medetomidine. Females had significantly higher mean eosinophil counts, albumin concentration, (and A/G ratio) and lower mature neutrophil counts, although these differences were not clinically relevant. Results for many of the blood parameters fall within the reference range for domestic cats. Mean values for alanine aminotransferase, aspartate aminotransferase, creatine phosphokinase, and lactate dehydrogenase activities as well as blood urea nitrogen, glucose, and sodium concentrations were higher than the upper limit of the reference range for domestic cats.

Handling stress and capture myopathy are important consequences of intensively managing wildlife species. Over the last 15 yr, the use of long-acting neuroleptic (LAN) drugs in wildlife has increased, and these drugs have become a valuable tool for decreasing capture and handling stress in many species. At this time, reports on the use of these drugs in North American species are limited. The major objective of this study was to evaluate the use of the LAN, zuclopenthixol acetate (Clopixol-Acuphase®), to decrease both quantifiable and subjective measurements of stress and activity in wild wapiti (Cervus elaphus, North American elk). This blinded, randomized study took place in February 1999 in Manitoba (Canada) and involved 11 animals receiving the drug and 12 animals acting as controls. At 24 hr after drug administration, there were measurable and significant decreases in the stress and activity of treated animals versus controls during handling. Treated animals had significantly lower mean body temperatures (39.0 versus 40.6 C), less hemoconcentration (mean packed cell volume 0.42 versus 0.49, mean hemoglobin 159.09 versus 181.75 g/L, mean total protein 65.0 versus 70.25 g/L), lower mean serum cortisol (97.91 versus 139.50 mmol/L), lower mean blood lactate (3.39 versus 5.98 mmol/L), and were less metabolically acidotic (mean pH_v 7.45 versus 7.34, mean bicarbonate 29.36 versus 24.25 mmol/L, mean base excess 5.64 versus −0.83 mmol/L). Only control animals had evidence of muscle damage based on serum biochemistry (creatine phosphate values of two animals of 42,080 and 25,887 U/L). No animals developed clinical capture myopathy, and no animals died. Measurable effects of this drug were still apparent at 72 hr post-administration. The results of this study support the use of Clopixol-Acuphase® in wapiti as a means to decrease handling stress and activity.

A frequently hypothesized but poorly studied cost of multiple mating in birds is that exposure to pathogenic sexually transmitted microbes (STM's) can lower reproductive success. Conversely, female birds may benefit from high frequencies of copulation and multiple copulation partners if they receive cloacal inoculations of beneficial STM's that can either protect them against future encounters with pathogens and/or serve as therapy against present infection. We examined the semen of 30 male tree swallows (Tachycineta bicolor) in 1998 to determine the presence and prevalence of potential pathogenic and beneficial STM's. Semen was collected directly from males after applying gentle pressure to the cloaca and we used standard microbiological techniques to identify microbes. We found that 19 of 30 samples contained one or more types of microbes. In these 19 positive samples, we isolated both pathogenic and beneficial microbes from 11, only pathogenic microbes from seven, and only beneficial microbes from one. This variation among males suggests that females would benefit from considering a particular male's potential as a donor of either pathogenic or beneficial STM's as a criterion for mate choice. There were few significant differences between males with pathogen-infected semen and those without pathogens in their semen in measures of size, morphology, and ectoparasite score and feather damage. Likewise, there were few significant differences between males with beneficial Lactobacilli spp. in their semen and those without Lactobacilli spp. in their semen in measures of size, morphology, and ectoparasite score and feather damage. We were unable to determine if there was a relationship between microbe presence and prevalence on reproductive performance.

A number of serological tests were compared for the detection of antibodies to Brucella abortus in bison (Bison bison). The performance of the fluorescence polarization assay (FPA) in both the preliminary evaluation and a subsequent blind validation indicated that this test was the most suitable for serological diagnosis of brucellosis in bison. The sensitivity and specificity in the preliminary evaluation were 92.1% and 99.4%, respectively. The sensitivity and specificity in a subsequent blind study were 96.3% and 97.6%, respectively. In a double blind study conducted on bison vaccinated with B. abortus strain 19, the data suggests that the FPA can differentiate bison infected with B. abortus from bison vaccinated with B. abortus strain 19. Both the indirect immunoassay (IELISA) and the competitive immunoassay (CELISA) performed nearly as well as the FPA. The buffered antigen plate agglutination test (BPAT) and the complement fixation test (CFT) did not perform as well as the FPA, CELISA or the IELISA in both studies. The FPA is a homogeneous assay eliminating the washing steps and reducing incubation to minutes rather than hours saving on time, equipment, materials, reagents and cost. These attributes, together, with its excellent sensitivity and specificity make the FPA an attractive test for the detection of serum antibodies to Brucella abortus in bison.

Brucella abortus strain RB51 is a laboratory-derived rough mutant of virulent B. abortus strain 2308 used as a vaccine because it induces antibodies that do not react on standard brucellosis serologic tests. Strain RB51 vaccine was evaluated in pregnant captive elk (Cervus elaphus) to determine (1) if it induced abortion and (2) if it protected against abortion following subsequent challenge. The time period of this study (February–June, 1998) was similar to field conditions where elk are vaccinated and possibly exposed to B. abortus. Fourteen elk were randomly and equally divided into vaccinated and control groups. The vaccinated group was vaccinated intramuscularly with 1.03 × 10¹⁰ colony-forming units (CFU) of strain RB51 and seroconverted postvaccination. Antibodies to strain RB51 were detected by a modification of an existing dot-blot assay. Both groups were challenged 40 days postvaccination with 9.8 × 10⁶ CFU of B. abortus strain 2308 administered intraconjunctivally. The first abortion occurred 38 days postchallenge. Abortion occurred in all control elk and in five of seven vaccinated elk 5 to 12 wk postchallenge (P = 0.23). Mixed strain RB51 and 2308 infections were present in fetuses and vaginas from the vaccinated group whereas only strain 2308 was cultured from control group fetuses and vaginal swabs. Further evaluation of strain RB51 will be necessary to determine if it will be safe and efficacious in free-ranging pregnant elk.

Some of the elk (Cervus elaphus nelsoni) of the Greater Yellowstone Area (Wyoming, Idaho, Montana; USA) are infected with Brucella abortus, the bacterium that causes bovine brucellosis. Brucella abortus strain RB51 vaccine is being considered as a means to control B. abortus induced abortions in cow elk. However, the most probable vaccination strategies for use in free-ranging elk might also result in some bull elk being inoculated, thus, it is important to insure that the vaccine is safe in these animals. In the winter of 1995, 10 free-ranging bull elk calves were captured, tested for B. abortus antibodies, and intramuscularly inoculated with 1.0 × 10⁹ colony forming units (CFU) of B. abortus strain RB51. Blood was collected for hemoculture and serology every 2 wk after inoculation for 14 wk. Beginning 4 mo postinoculation and continuing until 10 mo postinoculation elk were serially euthanized, necropsied, and tissues collected for culture and histopathology. These elk cleared the organism from the blood within 6 wk and from all tissues within 10 mo. No lesions attributable to B. abortus were found grossly and only minimal to mild lymphoplasmacytic epididymitis was found in a few elk on histologic examination. In a separate study, six adult bull elk from Wind Cave National Park (South Dakota, USA) were taken to a ranch near Carrington (North Dakota, USA). Three were orally inoculated with approximately 1.0 × 10¹⁰ CFU of RB51 and three were inoculated with corn syrup and saline. Ninety days post-inoculation semen was examined and cultured from these bulls. Strain RB51 was not cultured from their semen at that time. There were no palpable abnormalities in the genital tract and all elk produced viable sperm. Although they contain small sample sizes, these studies suggest that B. abortus strain RB51 is safe in bull elk.

We tested the efficacy of a single dose of Botumink® toxoid for protecting wild green-winged teal (Anas crecca) during botulism epizootics caused by Clostridium botulinum type C. We challenged control and immunized ducks with four different doses of type C botulinum toxin to determine the LD₅₀ for this species and to evaluate vaccine protection. Fewer immunized ducks were affected with botulism than control ducks, indicating that a single dose of Botumink® toxoid could increase the survival of ducks during epizootics. However, the frequency of immunized ducks with signs of botulism increased with the challenge dose of botulinum toxin. Even at doses of botulinum toxin approximately 2 to 4 green-winged teal LD₅₀, about 50% of the immunized ducks were affected. We believe an improved vaccine or a better delivery system is required to justify immunization of wild birds for experimental survival studies.

In order to determine the role of coyotes in the epidemiology of granulocytic and monocytic ehrlichial agents in California (USA), we tested 149 serum samples for antibodies against Ehrlichia equi, E. risticii, and E. canis, using an indirect immunofluorescent antibody test. Polymerase chain reaction (PCR) assay was used to survey for the presence of members of the E. phagocytophila genogroup, E. risticii and E. canis in blood samples of 95 coyotes. Sixty-eight (46%) samples were seropositive for E. equi, two (1%) for E. risticii and none of the samples had antibodies reactive to E. canis. Two and one coyote were positive for E. risticii and members of the E. phagocytophila genogroup by PCR assay, respectively. In contrast, the 95 samples were negative for E. canis by PCR. Ninety-five percent of the 68 E. equi seropositive coyotes and the one coyote PCR positive for members of the E. phagocytophila genogroup originated from a coastal area. However, the two E. risticii seropositive coyotes and the two coyotes PCR positive for E. risticii were from northern California. Sequence analysis of the three amplified PCR products revealed the agent to be similar in two coyotes to the sequences of E. risticii from horses originating from northern California and identical in one coyote to the agent of human granulocytic ehrlichiosis and E. equi from California. Thus, coyotes are exposed to granulocytic ehrlichiae and E. risticii and may play a role in the epidemiology of these ehrlichial agents in California.

An epizootic of vesicular disease occurred in a group of semi-domesticated California sea lions (Zalophus californianus) during the months of April and May 1997. Ten castrated mature male sea lions, ages 12 to 19 yr, were housed in three adjacent open-ocean net enclosures in San Diego Bay (California, USA). Four animals (40%) developed oral and extremity vesicles, anorexia, and were reluctant to perform learned behaviors. One animal developed vesicles but maintained a normal appetite and behavior. The remaining animals showed no clinical signs of infection. Virus (designated FADDL 7005) was isolated from four of the five animals that developed vesicles. Serum antibody titers to FADDL 7005, a previously untyped calicivirus, were demonstrated in animals that showed any combination of clinical signs and in two animals that did not show any clinical signs. No virus was isolated from five fecal samples collected from four of the group animals. Clinical signs lasted 4 to 20 days in affected animals. All affected animals recovered from infection. An experimental swine was inoculated with FADDL 7005 and developed vesicular disease, which was transmitted to another experimental swine upon contact. It is proposed that FADDL 7005 is a new San Miguel sea lion virus.

A longitudinal serologic survey was conducted for morbillivirus antibodies in Atlantic walruses (Odobenus rosmarus rosmarus), narwhal (Monodon monoceros), and beluga (Delphinapterus leucas) from the Northwest Territories, Nunavut and the St. Lawrence estuary (Canada). Sixty-five of 131 (50%) walruses sampled between 1984 and 1993 had detectable morbillivirus neutralizing antibodies. Positive walrus were identified from four of five Arctic sampling sites, to as far back as 1984. Prevalence of morbillivirus neutralizing antibodies in walruses from Foxe Basin ranged from a high of 76% (n = 21) in 1993 to a low of 22% (n = 28) in 1984. Limitations in sample acquisition may have produced underestimates for the 1984 data. There are no reports of clinical morbillivirus infection in walruses. Our results are consistent with the hypothesis that a morbillivirus similar or identical to phocine distemper virus (PDV) has circulated among walrus populations of the eastern Canadian Arctic, at least since the early 1980s. No narwhal (n = 79) or beluga (n = 445) from Arctic waters were identified as having antibodies to dolphin morbillivirus (DMV) above the threshold serum dilution of log₂ 4. Also, none of the beach-cast cetacean carcasses (n = 28) from the Gulf of St. Lawrence and the St. Lawrence estuary were positive for antibodies to DMV. This indicates that Gulf of St. Lawrence, St. Lawrence estuary, and Arctic cetaceans either have not been exposed to DMV or an antigenically related morbillivirus, or are not susceptible to infection.

Babesia isolates from an elk (Cervus elaphus canadensis) and a caribou (Rangifer tarandus caribou) with fatal infections were compared to Babesia odocoilei (Engeling isolate) from white-tailed deer (Odocoileus virginianus) by experimental infection, serologic, and small subunit ribosomal RNA (SSU rRNA) gene sequence analysis studies. Both the indirect fluorescent antibody test and immunoprecipitation assays demonstrated antigenic variation among the isolates. Experimental infection studies showed no clinical differences among the isolates. Nucleotide sequence analysis showed that the elk and caribou Babesia sp. isolates possessed SSU rRNA genes with identical sequences to that of B. odocoilei. A phylogenetic tree constructed from SSU rRNA gene sequences shows that B. odocoilei is most closely related to Babesia divergens, both of which branch together in the true babesia clade.

The epidemiology of Trichinella spp. in their main sylvatic hosts, wild boar (Sus scrofa ferus and red fox (Vulpes vulpes), in Extremadura (southwestern Spain) was studied. We examined 88 Trichinella spp.-positive wild boar muscle-tissue samples from a total of 29,333 killed animals, referred to the Veterinary Parasitology Department (University of Extremadura, Spain) by the Extremadura Veterinary Service. Additionally, 227 red foxes killed during the hunting season and thus not subject to veterinary controls were examined for trichinellosis. Trichinella spp. larvae were found in six (3%) of the red foxes. All samples were examined using direct diagnostic techniques, including trichinoscopy and artificial digestion. The mean intensity of infection was 74.8 larvae/g (LPG) of muscle tissue in wild boars, compared to 30.6 LPG in foxes. Trichinella spiralis (sensu stricto) predominated over T. britovi in wild boars. Random amplified polymorphic DNA (RAPD) and alloenzyme typing showed that 74% of infected wild boars had only T. spiralis, 21% had only T. britovi, and 5% showed mixed infections. In contrast, 33% of infected foxes were infected only with T. spiralis, while 67% had T. britovi, suggesting a clear predominance of the latter in foxes. We suspect the existence of a paranthropic or sylvatic cycle in large areas of this region; given the ease of transfer between sylvatic and domestic or semi-domestic animals, this implies a high epidemiological risk.

In order to determine a suitable procedure for isolating peripheral blood mononuclear cells (PBMCs) from loggerhead sea turtles (Caretta caretta), blood was collected using three different anticoagulants (sodium heparin, sodium citrate or potassium EDTA) and separated using a single step commercially-prepared arabinogalactan gradient of 1.077 g/ml density or multiple step Percoll gradients between 1.053 and 1.076 g/ml density (40–60% stock isotonic Percoll suspension). Heparinized blood centrifuged over a two-step 45/55% (1.059/1.070 g/ml) Percoll gradient yielded 99 to 100% mononuclear cells at the 45/55% interface. Mononuclear cell viability ranged from 85 to 97% with cell yields up to 9.2 × 10⁶ cells/mL. An unexpected finding was a population of low density granulocytes migrating to 40% (1.053 g/ml) and 45% Percoll layers in the multiple step gradients. These granulocytes could be eliminated from the PBMC preparation by use of the two-step 45/55% Percoll gradient. Isolated PBMCs can be used for cellular immunology and toxicology studies on these threatened marine organisms for which other tissues can usually be obtained only sporadically from post-mortem specimens.

Despite the extensive amount of research conducted on mourning doves (Zenaida macroura), no biochemical reference values exist for this species. Our objective, therefore, was to establish base line clinical chemistry reference values for mourning doves to assist with establishing clinical diagnoses. Wild mourning doves were captured 19 March 1996 to 8 August 1996, and 6 February 1998 to 12 May 1998; blood samples were collected from 382 mourning doves. Plasma biochemical values were established for glucose, sodium, potassium, chloride, enzymatic CO₂, albumin, total protein, globulin, calcium, phosphorus, cholesterol, magnesium, aspartate aminotransferase (AST), gamma glutamyl transferase (GGT), lactate dehydrogenase (LDH), and uric acid. These reference values are invaluable for determining diagnosis of diseases of the gastrointestinal, hepatic, renal, cardiovascular, musculoskeletal, and endocrine systems.

Telazol® was used to immobilize nine wild ocelots (Leopardus pardalis) captured in box-traps in southern Texas (USA) between May 1997 and April 1998. Mean (±SD) intramuscular dosage rate of 5.05 (±0.76) mg/ kg produced an induction time of 3.7 ± 1.8 min. Duration of cataleptic anesthesia was 67.4 ± 19.8 min and ocelots stood 50.0 ± 30.7 min after emergence from cataleptic anesthesia. Ocelots recovered to their preinjection condition 129.7 ± 28.8 min after first standing and 250.8 ± 55.1 min after initial injection. We observed no adverse reactions to Telazol® aside from minor loss of thermoregulatory control. Telazol® administered at 5 mg/kg was an effective and safe immobilizing agent for wild ocelots.

Survival of Trichomonas gallinae was examined in white-winged dove (Zenaida asiatica) carcasses to assess whether birds that have been dead up to 8 hr can be sampled reliably for this protozoan. Carcasses of 100 T. gallinae-positive white-winged doves were separated into four groups of 25 birds, representing 2, 4, 6, and 8 hr post mortem sampling intervals and placed into an environmental chamber maintained at 27 C and 75% relative humidity. Live T. gallinae were isolated in 96, 100, 100, and 92% of the carcasses at each of the respective post mortem intervals. The experiment was repeated with another 100 carcasses of T. gallinae-positive white-winged doves placed in the environmental chamber, this time maintained at 27 C and 40% relative humidity. Live T. gallinae occurred in 96, 100, 96, and 100% of the carcasses at each of the respective post mortem intervals. Across both trials, the overall ability to detect positive birds from sampling carcasses up to 8 hrs post mortem was 97%. An a posteriori experiment was conducted in which 23 and 18 carcasses from the second trial were maintained in the environmental chamber at 27 C and 40% relative humidity and resampled at 24 and 48 hr post mortem, respectively. Live trichomonads were isolated from 91 and 44% of the carcasses at 24 and 48 hr, respectively. Results suggest live T. gallinae can be obtained from dove carcasses reliably up to 8 hr and possibly up to 24 hr after host death. The ability for T. gallinae to survive within this time interval can aid wildlife personnel in monitoring this protozoan at hunter check stations or obtaining samples from recently killed birds.

Fifty-four black-tailed jackrabbits (Lepus californicus) (five juvenile males, 22 adult males, five juvenile females, and 22 adult females) from Humboldt County, California (USA) were evaluated for sex and age-specific differences in parasite prevalences and intensities, 26 February through 30 October 1996. Nematodes found included Biogastranema leporis in 42 hares (78% prevalence), Rauschia triangularis in 26 hares (48%), Trichostrongylus calcaratus in 14 hares (26%), and Trichuris sylvilagi in two hares (4%). Cestodes found included Taenia sp. cysticerci in five hares (9%) and Taenia sp. coenurus found in one hare (2%). Ectoparasites found included the ticks Dermacentor variabilis on 10 hares (19%) and Ixodes spinipalpis (=Ixodes neotomae) on nine hares (17%), as well as the anoplurid louse Haemodipsus setoni on 12 hares (22%). No significant differences in the parasite prevalences or intensities were found between male and female jackrabbits; this was for all males and females collectively, juvenile males and females only, as well as adult males and females only. Combining male and female hosts, adult jack-rabbits had a significantly higher prevalence of B. leporis and R. triangularis compared to juveniles. This is the first known report of Trichostrongylus calcaratus, Rauschia triangularis, Trichuris sylvilagi, and Dermacentor variabilis among black-tailed jackrabbits and the first known report of T. calcaratus and T. sylvilagi in the western USA. This is the first published report of I. spinipalpis, the vector for Lyme disease in California, on black-tailed jackrabbits.

Eighty-three free-living Eurasian buzzards (Buteo buteo) from three different areas in Germany were examined for adult stages and the metacercaria of the trematode Strigea falconispalumbi. Prevalences of adult parasites in the small intestine was 36% (Berlin/Brandenburg), 28% (Lower Saxony) and 3% (Baden-Württemberg). Metacercaria in the connective tissue of the neck were found in 58%, 55%, and 10% of birds from the respective areas. Significant differences in the prevalence of S. falconispalumbi adults and metacercaria between the areas were attributed to the different abundance of freshwater which is the key habitat for two intermediate hosts.

The heads of 137 white-tailed deer (Odocoileus virginianus) were collected on the opening day of the 1996 Missouri (USA) firearms deer season and surveyed for the presence of meningeal worm (Parelaphostrongylus tenuis). Eighteen percent of the deer examined were infected. Mean intensity of infection was 2.0 (range 1–7). There were no significant differences of infection or mean intensity when deer were classified and compared according to sex or age class.

A 16-yr-old adult male northern fur seal (Callorhinus ursinus) was found dead in its outdoor pool in November 1995. The animal was maintained at Mystic Aquarium (Mystic, Connecticut, USA) from March 1980 to November 1995. Gross necropsy findings included hemoperitoneum and locally extensive gastric intramural hemorrhage that involved the posterior fundic, antral, and pyloric regions and extended into the duodenum. The gastric mural thickening grossly resembled hemangioma, and the gastric serosa was ruptured at the site of maximal mural expansion. In histologic sections of the stomach, a cribiform network of fibrin, which encompassed numerous variably-sized aggregates of closely packed erythrocytes, markedly expanded the submucosa. No vascular endothelium was identified in serial histologic sections of the expanded gastric submucosa stained with hematoxylin and eosin or immunohistochemically with antibodies to vimentin and Factor VIII-related antigen, establishing an absence of hemangioma. Carstairs' and Weigert's histochemical stains confirmed that the framework expanding the submucosa was fibrin. Although the appearance of the gastric wall resembled hemangioma, a population of neoplastic endothelial cells was not identified within the submucosal expansion of hemorrhage and fibrin, and microscopic evidence was most consistent with the diagnosis of gastric intramural hematoma. This lesion is a rare pathologic event that has not been reported in marine mammals, but one that should be included in diagnostic considerations of hemoperitoneum and gastric mural expansion.

A captive adult female muskrat (Ondatra zibethicus) was found dead without previous signs of disease. At necropsy, abdominal organs were infiltrated with a poorly demarcated, soft, tan tissue. Microscopically this tissue was composed of neoplastic cells assuming two distinct growth characteristics consistent with Antoni A and B patterns. Ultrastructurally, the neoplastic cells were pleomorphic, lacked junctional devices, had abundant mitochondria and ergastoplasm, and frequently were closely associated with extracellular collagen. Immunocytochemical examination of tumor cells demonstrated sporadic expression of neuron specific enolase. Microscopic tumor metastases to the myocardium, ascending aorta, lungs and visceral pleura were present. This is the first report of a sarcoma compatible with a malignant peripheral nerve sheath tumor in a muskrat.

Canine distemper virus (CDV) is a serious disease of wild carnivores throughout the world. In Europe, infection has been detected in several carnivores including the Eurasian badger (Meles meles). In the present study 182 badger blood samples were collected from an intensively studied population of wild badgers in southwestern England (January–July, 1997), and a further 286 from throughout southern Britain (June 1996–November 1998). A neutralizing peroxidase-linked antibody test was used for the detection of antibodies against CDV. All the samples were negative for CDV antibodies, suggesting that in contrast to mainland Europe, the disease may be either absent or maintained at low levels in British badgers.

An outbreak of myxomatosis occurred between September and October 1993 on a rabbit farm in Punta Colnett (Ensenada, Baja California in northwestern Mexico, Transpeninsular Highway, km 128) and was confirmed by the Mexico-USA Commission for Prevention of Foreign Diseases of Animals (CPA). This represents the first officially confirmed case of the disease in Mexico. Like the cases in California (USA), the brush rabbit (Sylvilagus bachmani) seems to be the carrier of the virus, since serum samples from wild rabbits from different areas of the peninsula of Baja California were found to contain antibodies against the myxoma virus.

Free-living deer are suggested as a possible source of infection of cattle with bovine virus diarrhea (BVD) virus. To examine this hypothesis blood samples from 476 free-living deer were collected during two different periods and tested for BVD virus and antibody in Denmark. In 1995–96, 207 animals were tested. These included 149 roe deer (Capreolus capreolus), 29 fallow deer (Dama dama), 20 red deer (Cervus elaphus) and one sika deer (Cervus sika). For the remaining eight animals no species information was available. In 1998–99, 269 animals were tested including 212 roe deer and 57 red deer. The animals were selected from areas with a relatively high prevalence of cattle herds with a BVD persistent infection status in 1997 and 1998. All 207 samples from 1995–96 were found antibody-negative except two samples from red deer. Only 158 of the 207 samples were tested for virus and were all found negative. Of the 269 samples from 1998–99 all but one were antibody negative. The positive sample was from a red deer. All samples were virus-negative. It appears that BVD infection does not occur in roe deer in Denmark. The presence of antibody in a few red deer from various districts in Jutland probably results from cattle to deer transmission, rather than spread among deer. Hence, the possibility of free-living deer as a source of infection for cattle in Denmark seems to be remote.

As part of a white-tailed deer (Odocoileus virginianus) survival study in Missouri (USA) we were actively monitoring 97 radio-collared deer when 8 (8%) died. This mortality, which occurred from 20 August to 23 September 1996, consisted of five adult females, two yearling females and one yearling male. Based on the seasonality of this mortality and the isolation of epizootic hemorrhagic disease virus (EHDV) serotype 2 from one of these animals, we believe that these losses resulted from an epizootic of hemorrhagic disease. The remains of five unmarked deer that may have died from HD also were found on the study area during this same period. During the fall following this mortality, we tested serum from 96 deer taken by hunters in the immediate area. Fifteen (16%) were positive for EHDV or bluetongue virus (BTV) antibodies as determined by agar gel immunodiffusion tests. Serum neutralization test results indicated that previous infections were caused by EHDV virus serotype 2. Based on these data, and assuming that there was no prior exposure to EHDV serotype 2 in this population, the exposure rate for this epizootic was 24% of which 8% died. We noted hoof interruptions in only two of the 96 deer sampled. During this mortality event, the Missouri Department of Conservation received no reports of dead deer, and without the radio-monitored animals the event would have been undetected.

A deer was needle-exposed intravenously to Ehrlichia chaffeensis (Rickettsiales: Ehrlichieae) in canine macrophage (DH82) cells and 7 days later was infested with laboratory-reared Amblyomma maculatum (Koch) (Acari:Ixodidae) nymphs for acquisition feeding. After molting, the adult ticks were allowed to feed on a naive deer. The organism was reisolated from the needle-exposed deer by cell culture and E. chaffeensis DNA was detected in the deer's blood by PCR. Similar isolation/recovery techniques were used for the tick-exposed deer and no evidence of infection was found. Although these findings must be considered as preliminary owing to inadequate controls, the data suggest that A. maculatum is probably not a suitable vector for E. chaffeensis.

A novel Brucella sp. was isolated from lymph nodes of four ringed seals (Phoca hispida) collected near Pangnirtung (Baffin Island, Canada) in January and February 1995 and in one harp seal (Phoca groenlandica) collected near the Magdalen Islands (Gulf of St. Lawrence, Canada) in March 1996. Bacteriological characteristics were the same for all five isolates. The colonies were typical of Brucella spp., but took 2 to 5 days longer than the traditional species to appear on primary isolation media. Biotyping results did not match any of the known biovars of Brucella, but were similar to isolates of the genus Brucella previously reported from marine mammals inhabiting other areas of the northern hemisphere. This is the first confirmed report of brucellosis in marine mammals from Canada, and the first report of this organism in ringed and harp seals.