We assessed the potential for embedded steel and tungsten-bismuth-tin (TBT) shot to adversely affect health of mallards (Anas platyrhynchos). Ducks were implanted with three number four steel (n = 19) or TBT (n = 20) shot pellets in their pectoral muscles. None of seven hematology parameters measured differed in response to treatment (P ≥ 0.17). At necropsy 1, 2, 4, and 8 wk posttreatment, we observed only localized tissue reactions to embedded steel or TBT shot. Reactions differed grossly: after wk 1, embedded steel shot were enveloped in 0.5 to 2 mm grayish capsules, whereas TBT shot were surrounded by thinner (<0.5 mm), translucent capsules. Corrosion of steel shot was apparent. Microscopic lesions associated with steel shot were characterized by moderate to severe histiocytic and lymphocytic inflammation and considerable particle deposition, whereas histiocytic inflammation was mild and particle deposition minimal in TBT lesions. Overall scores of inflammation at steel shot implant sites were greater (P ≤ 0.043) than at TBT sites during wk 1 and 8. Inflammation at steel implant sites was relatively consistent over the 8-wk period, but decreased (P = 0.0017) at TBT sites by wk 8. Weights of steel shot recovered from muscle tissue declined logarithmically (R² = 0.978, P = 0.0014) over 8 wk, but TBT shot weights remained unchanged (P = 0.255). Embedded TBT shot, as compared to steel, resisted corrosion and induced comparatively mild inflammatory responses in mallard muscle tissue. However, inflammatory reactions to both embedded steel and TBT shot were localized and had no detectable systemic effects on mallard health under experimental conditions.

Five captive-raised pronghorn antelope (Antilocapra americana) were fed an alfalfa-grass hay diet containing 15 ppm total dietary selenium (Se) for 164 days. Four additional captive-raised pronghorns fed a similar diet containing approximately 0.3 ppm total dietary Se served as controls. None of the pronghorns had clinical signs attributable to the high Se hay. Plasma Se increased more rapidly than blood Se concentrations, from baseline concentrations (<0.15 g/ml) to >0.40 g/ml within the first 50 days on the high selenium diet, but thereafter declined to approximately 0.30 μg/ml. Mean primary antibody response to hen egg albumin was less in pronghorn on Se hay. No significant gross or histological lesions attributable to selenosis were found, nor was there any evidence of dystrophic hoof growth. The greatest Se tissue concentrations were found in liver and kidney (5.67 to 10.4 μg/g and 2.36 to 3.14 μg/g, respectively) from experimental animals; liver and kidney from the controls contained considerably less (≤0.52 μg/g and ≤0.61 μg/g, respectively). Exposure of pronghorns for more than 5 mo to a diet containing 15 ppm Se caused significant increases in plasma, liver and kidney Se concentrations, in the absence of clinical disease or pathologic lesions due to selenosis. Based on these results, we propose that pronghorns are less susceptible to selenosis than previously reported and that diagnostic criteria for the disease should be modified.

Captive mallards (Anas platyrhynchos) were fed wheat containing 5.8 ppm deoxynivalenol (DON, vomitoxin) from an outbreak of Fusarium graminearium head-blight that occurred on grain crops in Manitoba, Canada, during 1993. There was no evidence of taste aversion to this grain during a 10-day palatability trial. No significant differences were detected in serum protein, calcium, glucose, creatine kinase, aspartate aminotransferase or uric acid levels, blood packed cell volume, or body or organ weight, between ducks fed contaminated wheat and those fed uncontaminated wheat during a 14-day feeding trial. No gross or microscopic lesions were detected in birds fed contaminated wheat for 14 days. Based on these results, ducks will consume grain containing moderate levels of DON and short-term exposure to this grain will not result in obvious adverse effects.

From July 1990 to February 1991, nematode numbers in free-ranging snowshoe hares (Lepus americanus) at Kluane Lake, southwestern Yukon, Canada, were manipulated by subcutaneous injection (0.4 mg/kg) of ivermectin. Three field experiments were conducted to determine the degree of helminth loss associated with a single administration of ivermectin; the length of time that ivermectin was effective in reducing worm numbers; and the effect of repeated ivermectin administration in reducing worm numbers. Numbers of the nematodes, Protostrongylus boughtoni and Nematodirus triangularis were reduced by approximately 80% 2 wk after treatment with a single dose of ivermectin, and were still significantly lower than controls at 4 wk. However, beyond 2 wk, ivermectin did not affect the rate of acquisition of new worms of either species. All treated groups contained one or more hares in which numbers of P. boughtoni and N. triangularis were not reduced. In addition, ivermectin had no effect on numbers of Trichuris leporis or Passalurus sp. Overall, ivermectin was not as effective against the nematodes of free-ranging hares as has been reported for nematodes of domestic and laboratory animals.

Terrestrial gastropods were collected, 15 June to 25 November 1994, from beneath cardboard sheets on deer range in northeastern Minnesota (USA) and examined individually for larvae of Parelaphostrongylus tenuis, the meningeal worm of white-tailed deer (Odocoileus virginianus). Overall, 10 (0.08%) of 12,096 snails and slugs were infected with a mean (±SD) of 3.2 ± 2.5 P. tenuis larvae. The prevalence of infection in gastropods was greater in a traditional deer wintering yard (seven of 4,401, 0.16%), where deer aggregated for almost 5 months at a density of 50/km², than on summer range (three of 7,695, 0.04%) where they occurred at 4/km². Despite relatively low densities of infected gastropods, their ingestion purely by chance remains a tenable explanation for the high prevalence of P. tenuis infection observed in white-tailed deer.

Gastrointestinal and bronchopulmonary nematode infections and the efficacy of netobimin (Hapasil^®) were analyzed by way of fecal examination in 10 female mouflons (Ovis musimon), in central Spain, February 1993. Before treatment all 10 mouflons had Trichostrongylus axei, Teladorsagia circumcincta and Marshallagia spp.; six had Nematodirus spp., two had Trichuris sp., one had Capillaria sp., seven had bronchopulmonary Dictyocaulus filaria and 10 mouflons had protostrongylid lungworms (Muellerius capillaris, Protostrongylus rufescens, Cystocaulus ocreatus or Neostrongylus linearis). Netobimin (7.5 mg/kg) was 100% effective against T. axei, T. circumcincta, Marshallagia spp., and D. filaria infections whereas one animal continued eliminating Nematodirus spp. eggs. The drug also was effective against Capillaria spp. but not against Trichuris spp. or protostrongylid infections.

Nine species of nematodes, unidentified larval nematodes, three species of trematodes, two species of acanthocephalans and a single species of chewing louse were collected from 1993 to 1995 from 25 introduced whooping cranes (Grus americana) in Florida (USA). In spite of a quarantine procedure involving anthelmintic therapy, three helminth parasites may have been introduced from captive populations. Other parasites acquired were similar to those found in a local congener, the Florida sandhill crane (Grus canadensis pratensis), or only occurred infrequently.

Western blots and a kinetic enzyme-linked immunosorbent assay (ELISA) were used to characterize and quantify the prevalence of antibodies to Psoroptes sp. mites in elk (Cervus elaphus) from nine herds in North America. Sera from infested (n =18) and non-infested (n = 22) elk were used to optimize test methodology and to define cut-off values for negative, suspect, and positive samples. Among 357 samples, 35 (9.8%) of the animals were seropositive, 259 (73%) were negative, and 63 (18%) were suspect. Six of nine herds (67%) contained positive animals and two additional herds (22%) had suspect animals. Sex was not associated with prevalence of antibodies, but adults greater than 2 yr old were approximately five times more likely (95% confidence interval = 2.6–15.4) to be seropositive than calves. Based on these results, we propose that exposure to Psoroptes sp. mites may be widespread in free-ranging elk of North America.

Sarcoptic mange (Sarcoptes scabiei) occurred among wild ruminant species in five zoological gardens in Israel, from 1984 to 1994. Infestation of five ruminants by S. scabiei is reported for the first time: mountain gazelles (Gazella gazella), Nubian ibexes (Copra ibex nubiana), a barbary sheep (Ammotragus lervia), elands (Taurotragus oryx), and an Arabian oryx (Oryx leucoryx). All animals in the herds were administered ivermectin orally at a dose of 200 μg/kg body weight daily for 3 consecutive days. This was repeated three times at 2-wk intervals. The disease was eradicated in four small zoos, whereas in the biggest zoo, only control was achieved. Mortality among animals <4 mo and >8-yr-old animals composed 65% of mortality among all age classes.

Anaplasma ovis was experimentally transmitted from domestic sheep to elk (Cervus elaphus) and hack to splenectomized sheep. No rickettsemias were detected but serum from three of seven experimentally inoculated elk developed Anaplasma spp.-reactive antibody as measured by indirect immunofluorescence (IIF) or by the rapid card agglutination and complement fixation assays. Three elk were experimentally infected with A. marginale. The rickettsiae were detected in blood of these elk and caused disease in a splenectomized domestic bovine calf after subinoculation of blood from the elk. All three elk had positive titers with IIF. No clinical signs of illness were noted in any elk inoculated with either Anaplasma species.

We developed and validated an enzyme immunoassay for immunoreactive pregnanediol-3-glucuronide (iPdG) in feces to monitor reproductive status in desert and Rocky Mountain bighorn sheep (Ovis canadensis). Fecal iPdG concentrations were strongly correlated (r = 0.71) with serum progesterone concentrations in paired fecal and blood samples collected from 34 free-ranging desert bighorn sheep. In bimonthly fecal samples collected from 12 captive ewes, fecal iPdG profiles were similar between desert and Rocky Mountain bighorn sheep and we selected a pregnancy detection cutoff value of iPdG ≥1.8 ng/mg feces. Fecal iPdG concentrations always exceeded this cutoff value when samples were collected from about day 60 of pregnancy to a few days before parturition, but values <1.8 ng/mg (false negatives) were common for samples collected during the first 60 days of gestation. Although we tested a small number of known pregnant and non-pregnant ewes, the accuracy of the assay was 100% when two samples, collected 2 wk apart, were evaluated for any given ewe. Based on these data, this direct enzyme immunoassay for fecal progesterone metabolites has promise as a diagnostic tool to monitor hormone excretion and pregnancy in a free-ranging ungulate species.

Sera of 19 male and female bowhead whales (Balaena mysticetus) collected near Barrow, Alaska (USA) between 30 August and 13 October 1992 were evaluated for 18 serum chemistry values. Male bowhead whales had significantly greater creatinine and sodium concentrations, and significantly lower glucose concentrations than females. Pregnant females had greater triglyceride levels than non-pregnant females. The mean concentrations of creatinine, blood urea nitrogen, alkaline phosphatase, total bilirubin, total protein, sodium, potassium, chloride, phosphorus, and calcium were similar to those previously reported from bowhead whales. High aspartate aminotransferase and creatine kinase levels were attributed to muscle damage associated with harpooning.

Between October 1991 and February 1992, 41 of 53 known adult and subadult Ethiopian wolves (Canis simensis) in five adjacent packs in the Bale Mountains National Park, Ethiopia, died or disappeared. Brain smears from two carcasses were positive for rabies by the immunofluorescence test, and rabies virus was isolated from the brains by mouse inoculation. Based on monoclonal antibody tests on the mouse brains, we identified the virus as a minor variant of the serotype 1 rabies viruses found in domestic dogs and wild canids of Africa. Sera from two of 15 Ethiopian wolves had rabies virus neutralizing antibody.

The ability of native Swedish birds to produce and maintain production of Ockelbo virus neutralizing (Nt) antibodies were evaluated experimentally between 6 June 1990 and 27 July 1991. After experimental infection of 57 birds of the orders Anseriformes and Passeriformes with Ockelbo virus, these birds were examined for Ockelbo virus Nt antibodies at 5 days, and at 1, 3, 6, 9, and 12 mo after inoculation. One month after inoculation, Nt antibodies were more prevalent in birds with a detectable viremia (100%, n = 22) than in non-viremic birds (65%, n = 26). The Nt antibody prevalence varied over time among taxa; detectable antibodies occurred earlier after inoculation and for a longer time in Anseriformes than in Passerifonnes. By 5 days after inoculation, antibodies could be detected in 22 (71%) of 31 Anseriformes but in none of 16 Passeriformes. However, at 1 mo the antibody prevalences at 1 mo were similar: 84% among the Anseriformes and 73% among the Passeriformes; at 3 mo the prevalences were 50% in Anseriformes and 15% in Passeriformes. Forty-two percent of the Anseriformes had detectable antibodies even 12 mo after inoculation.

Four moose (Alces alces) were inoculated conjunctivally with B. abortus biovar 1 to determine their susceptibility to brucellosis, and to describe the serology, bacteriology, hematology, clinical chemistry, and pathology associated with infection. All moose became infected. Two moose were killed at day 70 post-exposure, one (83F) died acutely at day 85, and one was killed at day 166. None of the moose had clinical signs, except for 83F immediately before death. Infected moose were readily detected serologically by the buffered antigen plate test, Brewer card test, standard tube agglutination test, and complement fixation test as used for brucellosis in cattle. With the exception of samples from 83F taken 24 hours before death, clinical chemistry, and hematology results were stable for all moose, and similar to normal values seen in cattle. Lesions seen in all moose were indicative of endotoxemia, and moose 83F died of acute endotoxic shock. Brucella abortus biovar 1 was isolated from several tissues in all moose, most notably from lymph nodes where counts often exceeded 4 × 10⁴ colony forming units per g of tissue. Thus infection with B. abortus will kill moose, and progression of the disease is likely rapid under field conditions. Moose appear to be a dead-end host for brucellosis.

Osteoporotic lesions were evaluated in the skulls of moose (Alces alces) collected in Isle Royale National Park, Michigan (USA), from 1958 to 1994. Circular lesions which penetrated the outer table of the skull were distributed over the frontal and nasal bones asymmetrically in both sexes. About 32% of skulls recovered had some porotic lesions with slightly greater prevalence among males.

Between 1980 and 1994, 586 individuals of 20 native reptile and amphibian species were evaluated at a wildlife rehabilitation facility in DuPage County, Illinois (USA). On examination, 48% of reptiles and 52% of amphibians were injured, and 2% of each class were diseased; remaining animals were uninjured. The most frequent causes of injury to reptiles were automobile collisions (55%), ingestion of fishing tackle (19%), and domestic animal attacks (8%). Automobile collisions (38%), lawn and garden accidents (33%), and pet collection (19%) were the most frequent causes of injury to amphibians. We released 354 reptiles and 54 amphibians into appropriate habitat available in local forest preserves, representing case release prevalences of 84% and 68% for each class, respectively.

Red-winged blackbirds (Agelaius phoeniceus) were collected during an epizootic in southeastern North Carolina (USA). Activity of brain cholinesterase (ChE) was inhibited by 14 to 48% in three of five specimens, and returned to normal levels after incubation. Gastrointestinal tracts were analyzed for 30 anti-ChE agents. Carbofuran, the only compound detected, was present in all specimens at levels from 5.44 to 72.7 μg/g wet weight. Application of granular carbofuran in an adjacent corn field, results of necropsy examinations, and chemical analyses are consistent with a diagnosis of carbofuran poisoning in these specimens.

We tested the in vitro sensitivity of Macropodid Herpesvirus 2 to eight commonly used anti-herpetic compounds using plaque reduction tests, March and April, 1995. The virus was most susceptible to inhibition by (E)-5-(2′-bromovinyl)-2′-deoxyuridine and adenine 9-(β-D-arabino-furanoside. Both compounds have been used for anti-herpetic therapy in humans and may prove useful in the treatment of macropodoids in captivity.

Exposure to one or more serovars of Leptospira interrogans was observed in five of six sampled elk (Cervus elaphus roosevelti) killed in November 1993, from an isolated herd in southwest Washington, USA (46°45′N, 123°6′W). In April 1994, exposure to L. interrogans serovars was documented in nine of 11 captured cow elk from the same herd. Leptospiras were not isolated from any of the exposed elk, and 10 of the 11 cows were pregnant. The high seroprevalence is evidence that exposure is widespread in the herd. Local productivity of elk was high, however, and the surrounding topography was not conducive for transmission to other elk populations.

From February to September 1993, ten adult female mouflons (Ovis musimon) and their five offspring from central Spain were examined weekly for coccidial infection. All adult mouflons had Eimeria spp. infections with mean (±SD) intensity of 1,869 (±1,264) oocysts per gram of feces the day of capture, increasing progressively during the first two months in captivity and later returning to the initial values (1,869 ± 1,547). The mean (±SD) oocyst shedding in young animals was 16,800 (±966) oocysts per gram at 1 mo and 18,796 (±1,220) at 1.5 mo of age and more than 40,000 (40,250 to 52,000) at 3 mo of age; this high intensity was associated with a transient diarrhea. The species involved, in order of frequency, were E. bakuensis (syn. Eimeria ovina), E. ovinoidalis, E. crandallis, E. caprovina, E. parva, E. faurei, E. granulosa and E. intricata, and one more not previously described and recorded as Eimeria sp.. The predominant species for both age groups was E. bakuensis.

In June 1993 an unusual coccidian parasite was identified in lung tissue from a northern cardinal (Cardinalis cardinalis) collected near Tucson, Arizona (USA), which died in respiratory distress. Histologically, there was evidence of severe, generalized interstitial pneumonia, associated with the parasite. Both asexual and sexual stages were seen. Schizonts, gamonts, and sporulated oocysts were seen in lung tissue. The parasite most closely resembled coccidia of the genus Lankesterella. This is the first report of such a coccidian parasite in the alveolar tissue of a cardinal.

Between 1988 and 1994, 16 definitive and 26 presumptive cases of tick paralysis were diagnosed in 10 species of birds from five southeastern states in the USA. All birds had engorged adult female Ixodes brunneus ticks on the head region and were partially paralyzed or dead. Cases occurred in the winter and early spring months, and most birds were passerines found in private yards or near feeders. All stages of I. brunneus feed exclusively on birds, and this species previously has been associated with avian tick paralysis. Little is known concerning the life cycle of this ixodid tick and its impact on wild bird populations.

The livers of impala (Aepyceros melampus) collected in the Mlawula-Mbuluzi-Simunye Nature Reserve and Protected Area complex in northeastern Swaziland from October 1985 to September 1986 were infected with three species of helminths: a nematode (Cooperioides hepaticae), a cestode (Stilesia hepatica), and a trematode (Fasciola gigantica). Cooperioides hepaticae caused a severe cholangitis. Lambs were infected at 1.5 to 2 mo of age, and the prevalence increased to 100% by 5 mo of age. The prevalence was 82% in yearlings and 44% in adults, with the highest prevalence and intensity of infection at the end of the dry season. Stilesia hepatica was found primarily in adults. Heavy infections caused a thickening and distension of the main bile ducts, but no changes were evident in the liver parenchyma. Fasciola gigantica, found only in one adult male, caused a thickening and distension of main bile duct. There was no apparent association between the helminth infections and body condition.

Hematological and serum biochemical values were determined in a wild population of the mountain brushtail possum (Trichosurus caninus) at Cambarville, central Victoria, southeastern Australia. Animals were sampled during two-week trapping periods in June, September, and December 1992, and April 1993. Values for hemoglobin, red cell count and hematocrit were significantly higher in males than females. Total protein and mean corpuscular volume (MCV) were significantly higher in female T. caninus. Significant seasonal variations were detected for total bilirubin, alkaline phosphatase, total protein, albumin, urea, absolute eosinophils, MCV, sodium, potassium, and phosphate.

Telazol^® (tiletamine hydrochloride and zolazepam hydrochloride combination) and a combination of ketamine hydrochloride and acepromazine were used to immobilize wild Ethiopian wolves (Canis simensis) in Ethiopia from 1988 to 1992. Telazol^® doses of 2.1 to 6.5 mg/kg resulted in a mean (±SD) induction time of 2.3 ± 0.9 min and a mean (±SD) immobilization time of 82.2 ± 28.6 min. Induction time did not differ by dose, wolf weight, or age, but was significantly longer for females. Immobilization time differed with dose, but not by wolf weight, age, or sex. Total recovery times ranged from 50 to 158 min. There were no apparent side effects on immobilized animals. Wolves immobilized using a combination of ketamine hydrochloride and acetylpromazine had longer induction time (3.0 ± 0.8 min) and recovery time (114.7 ± 29.2 min). Telazol^® is an effective and safe agent for immobilizing Ethiopian wolves and is preferred to ketamine/acetylpromazine.

The effectiveness of ketamine and xylazine as an immobilizing combination for muskrats (Ondatra zibethicus) was evaluated. Eleven muskrats were intramuscularly injected using a high (n = 7) or low (n =4) dosage of a 20:1 mixture of ketamine (12 or 20 mg) and xylazine (0.6 or 1.0 mg) in Carlton County, Minnesota (USA) from 1 to 4 May 1995. Mean (±SD) induction times for muskrats receiving a high dosage (6.5 ± 2.6 min) or low dosage (7.0 ± 1.6 min) was similar (P = 0.71). In contrast, muskrats receiving a low dosage recovered sooner (37.0 ± 15.1 min) than muskrats receiving a high dosage (62.2 ± 15.6 min) (P = 0.04). There was a positive linear relationship (r² = 0.75, P = 0.02) between the amount (mg/kg) of ketamine-xylazine injected and recovery time but not between the amount injected and induction time (r² = 0.49, P = 0.18). Heart rate, respiratory rate, and body temperature were similar (P = 0.20 to 0.62) between high and low dose groups. No mortality occurred nor were short-term adverse effects observed in recaptured individuals. I conclude that a 20:1 mixture of ketamine-xylazine is a safe and effective immobilization agent for muskrats when conducting non-surgical field procedures. Immobilizing muskrats with 15 mg/kg ketamine and 0.75 mg/kg xylazine should provide about 10 min of handling time before arousal and allow full recovery in <60 min.