Prevalence and intensity of the tick, Haemaphysalis leporispalustris, were monitored during 1963 to 1976 in a cyclic snowshoe hare (Lepus americanus) population near Rochester, Alberta, Canada. Prevalence was near zero from December through March, and near 100% among adult hares from May through September. Prevalence among juvenile hares approached 100% by age 2 mo. Intensity peaked for both adults and juveniles during May–June and again in August. Mean intensities were significantly higher among adult males than adult females in 5 of 13 yr, and almost significant in two others. Tick intensities were lowest during 3 yr, 1969 to 1971, when hare densities were highest. Tick intensities in spring were correlated with intensities the previous fall. Survival of marked adult and juvenile hares was unrelated to intensities of infestation. Mean numbers of corpora lutea and embryos tended to be lower among adult females with heavy tick infestations, and intra-uterine losses rose steadily from about 3 to 13% as tick intensities increased from none to heavy. Comparison of average tick intensities on adults 1-, 2-, and ≥3-yr-old yielded no evidence of increased immunity with age.

Two species of hematozoa, Haemoproteus columbae and H. sacharovi, were observed on thin blood smears from populations of mourning doves (Zenaida macroura) in the Rolling Plains (RP, a semiarid dryland farming and grazing area) and Southern High Plains (SHP, an intensively cultivated and irrigated agricultural region with playa lakes) of western Texas (USA). Prevalences of H. columbae and H. sacharovi were 91 and 18% in doves from the RP (n = 44 doves examined) and 81 and 36% in those from the SHP (n = 84), respectively. Although the prevalences of these species were not significantly different between the RP and SHP, the prevalence of H. sacharovi was significantly greater in juvenile versus adult doves from both localities. Mixed infections of both haemoproteid species occurred in 11 and 24% of the doves from the RP and SHP, respectively. The frequency distributions of the relative density values (numbers of parasites/2,000 erythrocytes counted) of H. columbae and H. sacharovi were overdispersed in hosts from both localities. Relative densities of H. columbae were significantly higher in mourning doves from the RP versus the SHP; likewise those of H. sacharovi were significantly greater in juvenile versus adult doves and between localities. Observed differences in prevalence and relative density of the two species in the haemoproteid community across spatial and host variables may reflect differences in vector transmission and in the physiological and immunological status of the host. This study emphasizes the importance of using adequately quantified density data versus only prevalence data when examining microparasite communities at the component community level.

The occurrence and seasonal patterns of transmission of the blood protozoa of wild turkeys (Meleagris gallopavo silvestris) were studied at Tallahala Wildlife Management Area (TWMA) (Jasper County, Mississippi, USA). Blood smears obtained from wild turkeys in winter, spring and summer, and from sentinel domestic turkeys throughout the year were examined for Haemoproteus meleagridis and Leucocytozoon smithi. Whole blood from wild turkeys captured in summer was subinoculated into malaria-free domestic turkey poults and recipient birds were examined for Plasmodium spp. The prevalence of H. meleagridis and L. smithi were not different (P > 0.05) between adults and juveniles or between male and female turkeys in any season. Leucocytozoon smithi was not detected in poults in summer or in juveniles examined in winter. Sentinel studies and information from wild birds revealed that transmission of H. meleagridis and L. smithi did not overlap. Haemoproteus meleagridis was transmitted from May through November, while L. smithi was transmitted only from January through April. The onset of transmission of H. meleagridis coincided with peak hatching (mid-May) and brood-rearing (May–November) of turkey poults. Plasmodium spp. were not found in turkeys from TWMA (n = 27) nor in birds from three widely separated counties (n = 28) in Mississippi.

Helminths are reported for the first time from ermines (Mustela erminea) and martens (Martes americana) in Washington (USA). Among 22 adult ermines, 41% were infected by one or more of five species (Taenia mustelae, Alaria mustelae, Molineus patens, M. mustelae and Trichinella spiralis). Among 78 adult martens from three geographic localities, the prevalence was 83%. Nine species were identified (Mesocestoides sp., T. mustelae and T. martis americana, Euryhelmis squamula, M. patens, Baylisascaris devosi, Physaloptera sp., Soboliphyme baturini and T. spiralis). Trichinella spiralis occurred with a maximum prevalence of 50% in martens, but only occurred in 9% of ermines. Compression and digestion techniques provided a similar estimate of prevalence of T. spiralis, yet neither was entirely accurate in identifying all infected hosts. The species richness of the helminth community of martens in Washington was greater than that reported from other regions of North America.

During the 1988 hunting season, livers and lungs from 263 mule deer (Odocoileus hemionus hemionus), 198 moose (Alces alces), 147 white-tailed deer (Odocoileus virginianus), and 94 wapiti (Cervus elaphus nelsoni) from Alberta (Canada) were collected for parasitological examination. Most of the samples (89%) were submitted by big game hunters throughout the province. Giant liver fluke (Fascioloides magna) was found in 9% of 22 yearling and 29% of 65 adult wapiti; 4% of 161 adult moose; and 2% of 97 adult white-tailed deer. The intensity of infection generally was low; however, one wapiti had over 600 flukes in the liver. Infections were restricted to alpine and montane regions in southwestern Alberta (97%) as well as boreal uplands of the Cypress Hills in southeastern Alberta (3%). Other parasites recorded included Taenia hydatigena cysts in liver of 61% of 191 moose and 14% of 247 mule deer. Dictyocaulus viviparus was found in lungs of 14% of 50 moose, 14% of 118 mule deer, 12% of 41 wapiti, and 6% of 54 white-tailed deer. Echinococcus granulosus cysts were found in lungs (and occasionally liver) of 37% of 51 moose. Incidental infections of Thysanosoma actinoides, Orthostrongylus macrotis, and Taenia omissa were recorded. Adult Dicrocoelium dendriticum were collected from liver of two wapiti, one mule deer, and one white-tailed deer from the Cypress Hills.

Case records of 683 white-tailed deer (Odocoileus virginianus) submitted to the Southeastern Cooperative Wildlife Disease Study (Georgia, USA) for diagnostic purposes from 1971 to 1989 were reviewed for the occurrence of pyogenic infections of the central nervous system, specifically intracranial abscessation or suppurative meningoencephalitis. These conditions, either alone or in combination, were diagnosed in 24 of 683 (4%) deer. Thirteen genera of bacteria were isolated; the most frequent species was Actinomyces pyogenes. The disease was strongly sex biased (P < 0.01); 88% of the cases occurred in males. Cases were more prevalent (P < 0.05) in older bucks; the median age of infected bucks was 3.2 yr, and 71% of these were ≥2.5-yr-old. Intracranial abscessation/suppurative meningoencephalitis cases accounted for 20% of the diagnoses among 56 bucks ≥3-yr-old. Cases were seasonal, occurring only from October to April. Characteristic necrosis, erosion, and pitting of skull bones were common, and this bone damage may be useful in determining cause of death when only skeletal remains are found. Males, especially older bucks, apparently are predisposed to intracranial abscessation/suppurative meningoencephalitis because of the cycle of antler development and behavioral traits associated with reproduction. The strong bias toward prime age bucks suggests that these infections could specifically hinder management strategies designed to produce populations with older buck age structures.

Wild turkeys (Meleagridis gallopavo silvestris) trapped as part of a relocation program by the Arkansas Game and Fish Commission were tested for selected infectious diseases and parasites. The 45 birds were trapped at four locations in Pope, Scott, and Montgomery counties (Arkansas, USA). Forty-four blood samples for serology, 27 blood smears and 12 fecal samples were collected. Of the serum samples tested, 20 of 44 (45%) were positive for Pasteurella multocida by enzyme-linked immunosorbent assay (ELISA), 42 of 44 (95%) were positive for Bordetella avium by ELISA, and 15 of 44 (34%) were positive for Newcastle disease virus antibody by the hemagglutination inhibition test. All serum samples were negative for Mycoplasma gallisepticum, Mycoplasma synoviae, avian paramyxovirus 3, avian influenza, hemorrhagic enteritis, Marek's disease, avian encephalomyelitis, laryngotracheitis, Salmonella pullorum and Salmonella gallinarum. Haemoproteus meleagridis was found in eight of 27 (30%) and Leucocytozoon smithi in nine of 27 (33%) blood smears; all smears were negative for Plasmodium hermani. Enteric parasites included Ascaridia dissimilis, Heterakis gallinarum, Eimeria dispersa and Raillietina spp. This study was an attempt to document the health status and disease exposure of wild turkeys in Arkansas to aid in managing and preventing the spread of disease agents to wild turkeys and other species of birds.

Brain tissues from 128 rabid animals from Florida in 1987 and 1988 were analyzed with monoclonal antibodies and cases were mapped by species and antigenic variant. The single variant found in terrestrial animals was distinguished easily from the variety of antigenic variants identified for infected bats, and there was no evidence of transmission of rabies between bats and terrestrial animals. The raccoon (Procyon lotor) appeared to be the sole maintenance source for terrestrial animal rabies in Florida.

A series of experiments are described on the acceptance, by red foxes (Vulpes vulpes) and other species, of two types of vaccine-baits intended to deliver liquid rabies vaccine. The baits consisted of a cube of sponge coated in a mixture of tallow and wax, or a plastic blister-pack embedded in tallow. All baits contained tetracycline as a biological marking agent: examination of thin sections of carnivore canines under an ultraviolet microscope revealed a fluorescent line of tetracycline if an individual had eaten baits. Baits were dropped from fixed-wing aircraft flying about 100 m above ground at approximately 130 km/h. Flight lines followed the edges of woodlots midway between parallel roads. Baits were dropped at one/sec, resulting in one bait/36 m on the ground, or 17 to 25 baits per km². Crows (Corvus brachyrhynchos) removed many baits, but did not appear to lower the percent of the fox population which took bait. Dropping baits only into corn and woodland to conceal baits, to reduce depredation by crows, reduced acceptance by foxes. Acceptance by foxes ranged between 37 and 68%. Meat added as an attractant did not raise acceptance. Presence, absence, color and perforations of plastic bags did not alter bait acceptance. Dispersal by juvenile foxes probably lowered the estimates of bait acceptance. It took 7 to 17 days for 80% (n = 330) of foxes to eat their first bait. The rapidity with which foxes picked up their first bait appeared more affected by unknown characteristics of years or study areas than by experimental variables. Skunks (Mephitis mephitis) and raccoons (Procyon lotor) also ate these baits, but acceptance was lower. Small mammals contacted baits, but rarely contacted the vaccine, which had the potential for vaccine-induced rabies in some species. Aerial distribution of baits was more cost-effective than ground distribution as practiced in Europe. This system has potential for field control of rabies, although higher acceptance will be desirable.

A field study was conducted on Ossabaw Island, Georgia (USA) to determine the feasibility of delivering oral vaccines to wild swine (Sus scrofa). Baits were made of polymer-bound fish meal and contained a gelatin capsule as a potential vaccine chamber. Two biomarkers, iophenoxic acid and tetracycline, were incorporated into each bait, and soured chicken mash was used as an attractant. Baits (n = 1,980) were distributed in a grid pattern on a 405-ha test site and monitored for animal disturbance. Within 72 hr, 88% of 393 monitored baits were gone, and observations of track-beds surrounding 100 baits indicated that at least 52% were taken by wild swine. Subsequent testing of 80 wild swine for the biomarkers revealed that 95% of the animals had consumed bait. Track-bed observations indicated that raccoons (Procyon lotor) were the only non-target animal that frequently took baits. Biomarker analyses indicated 44% of 16 raccoons tested had eaten bait. It was concluded that oral vaccine delivery to wild swine should be considered as a feasible method of control or eradication of pseudorabies and/or swine brucellosis in wild swine if effective vaccines become available.

The C120 Magnum trap, equipped with a 66 × 69 mm pan trigger, which favored double strikes in the neck and thorax regions, successfully killed nine of nine wild mink (Mustela vison) in simulated natural conditions. Average times to loss of consciousness and heartbeat were estimated at <72 (±24) sec and 158 (±48) sec, respectively, after firing of the trap. This study confirmed that the C120 Magnum trap can be expected to render >79% of all captured mink unconscious in ≤3 min (P < 0.05). This is the first mink kill trap to meet the requisites of the Canadian General Standards Board regarding killing traps.

A plate agglutination method was developed to test sera from free-ranging snowshoe hares (Lepus americanus) captured in Alaska (USA) or Alberta (Canada) for antibody against Actinobacillus capsulatus. Antiserum against A. capsulatus was prepared in a domestic rabbit. A concentrated suspension of formalin-killed A. capsulatus was prepared for use as an antigen. Serum antibody prevalence for hares was 98 of 239 (41%) in Alaska and 51 of 111 (46%) in Alberta. Prevalence in Alaska peaked in 1981 corresponding to a peak in hare population density. Seasonal prevalence peaked in May in Alaska. Prevalence at one capture site in Alaska was significantly higher than at four other sites. There was no difference in sex-specific prevalence for either Alaska or Alberta.

Xylazine hydrochloride was used to immobilize 124 Rocky Mountain bighorn sheep (Ovis canadensis canadensis) between 1983 and 1988. Doses of xylazine for free-ranging lambs ranged from 70 to 130 mg with amounts increasing with lamb age. Average doses for 11 free-ranging adult males and 21 adult females darted from the ground were (x̄ ± SE) 363 ± 16 and 251 ± 7 mg, respectively. Adult females captured in “Stevenson's” box traps (n = 7) could be immobilized with significantly (P < 0.001) less xylazine (93 ± 9 mg) than free-ranging females but had similar induction times. Long recovery times associated with xylazine immobilization were eliminated with the intravenous administration of idazoxan (RX 781094) at an approximate dosage of 0.1 mg/kg. Eighteen sheep given idazoxan appeared fully recovered within 3 min of injection (x̄ ± SE = 1.2 ± 0.2 min). Four mortalities (three lambs, one yearling male) (3% of total) occurred before idazoxan was available for trial.

In the fall of 1988 all five animals in a herd of muskoxen (Ovibos moschatus) developed clinical signs of posterior ataxia. Postmortem investigation revealed inflammatory lesions of the caudal part of the spinal cord, mainly as leptomeningitis. Nematodes were seen in close association with the lesions. Although not identified, the parasites were probably an Elaphostrongylus sp.

Adults of the large nematode, Toxocara pteropodis, have not previously been reported from extra-intestinal sites in their hosts, juvenile flying-foxes (fruit-bats of the genus Pteropus). In one captive bat which died unexpectedly, a nematode was found coiled within the gall bladder and common bile duct; in another, a nematode was in the esophagus and protruded into the laryngopharynx. Like other ascaridoids, this species is capable of aberrant migration.

Dorsal-spined larvae in fecal samples from free-ranging white-tailed deer (Odocoileus virginianus) in Michigan and Pennsylvania were used as a source of larvae to infect a hand-raised white-tailed deer fawn. The fawn received 200 third-stage larvae and passed dorsal-spined larvae in feces 66 days later. Muscleworm (Parelaphostrongylus andersoni), and meningeal worm (Parelaphostrongylus tenuis) were recovered at necropsy. Two white-tailed deer and seven wapiti (Cervus elaphus) exposed to larvae of the source from Pennsylvania harbored only P. tenuis. This is the first report of P. andersoni in the midwestern United States and extends the known range of this muscle-worm in free-ranging white-tailed deer. Concurrent infections of P. andersoni and P. tenuis have not been established previously in experimentally infected fawns.

Two cases of dioctophymosis in wild little grisons (Galictis cuja) were found in Parana State (southern Brazil). One female host was infected with eight nematodes and a male harbored a single parasite. This represents the first report of the giant kidney nematode (Dioctophyme renale) in the little grison.

A new host and geographic locality record is reported for tetrathyridia of Mesocestoides sp. in two species of ranid frogs (Rana berlandieri and R. pipiens) from Texas and New York, respectively. Tetrathyridia were found encapsulated in liver and mesenteries of the hosts. Morphological examination and experimental inoculation of these tetrathyridia into mice demonstrated the absence of capacity for asexual proliferation. Overall prevalence of infection was low in anurans from Arkansas, Texas and New York, but intensities can be generally high. In addition, a summary of frogs and toads from North America reported as hosts of tetrathyridia of Mesocestoides sp. is presented.

Twenty-four of 87 (28%) parthe-nogenetic Chihuahuan spotted whiptails (Cnemidophorus exsanguis) from nine counties of New Mexico and seven counties of Texas were infected with one or more endoparasites. These included a linstowiid cestode (Oochoristica bivitellobata) in seven (8%), a larval spirurid nematode (Physaloptera sp.) in nine (10%) and an oxyurid nematode (Pharyngodon warneri) in 10 (11%). This note, the third in a series of reports on helminths of Cnemidophorus spp., documents parasites in C. exsanguis for the first time.

Fecal samples from 155 mantled howling monkeys (Alouatta palliata palliata) examined at Centro Ecologico La Pacifica, Guanacaste Province, Costa Rica, revealed 75 (48%) had parasitic infections. A sampling of nine howling monkeys from Santa Rosa National Park, Costa Rica indicated only one infected animal (11%). Only three of 19 (16%) spider monkeys (Ateles geoffroyi) also from Santa Rosa were infected. Controrchis biliophilus, Trypanoxyuris minutus, unidentified strongylid eggs and Isospora sp. oocysts were found. Three monkeys from La Pacifica died and were examined for adult helminths. They were infected with Ascaris lumbricoides, C. biliophilus and T. minutus.

A state-wide survey to determine the occurrence and comparative numbers of ticks infecting white-tailed deer (Odocoileus virginianus) was conducted in North Carolina (USA). One thousand six hundred twenty nine deer were examined in 60 of 100 counties; with the exception of one county in the piedmont region, all tick-infested deer occurred in the coastal plain. Ixodes scapularis (46%) and Amblyomma americanum (53%) were the most prevalent species encountered and accounted for more than 98% of the 4,286 ticks collected. Some specimens of Dermacentor albipictus and Amblyomma maculatum also were collected.

Thirteen Rocky Mountain bighorn sheep (Ovis canadensis canadensis) with clinical signs of psoroptic scabies were captured in Wyoming. Signs included droopy ears, depilation on the head and neck, and exudate in the ears. Mites were identified as either Psoroptes cervinus or P. equi. Two ewes with scabies at the time of original capture had no clinical signs of mite infection 1 and 2 yr later.

Infections caused by a Sphaerospora sp. resembling S. chinensis are reported for the first time in goldfish (Carassius auratus) from North America. The myxosporean was found in the respiratory epithelium of the gill of pond-reared fish. Spores from stained tissue sections were spherical with an equal mean length and width of 6.3 μm. Spore valves were thickened at the suture which lies in a plane perpendicular to two prominent pyriform polar capsules. The polar capsules were 4.0 × 2.8 μm in length and width. Both monosporous and disporous development within a surrounding “pseudoplasmodium” was detected. Infections caused moderate hyperplasia and occasional necrosis of the respiratory epithelial cells of the gill.

Gray wolves (Canis lupus) were immobilized with 0.5 mg/kg xylazine plus 7.5 μg/kg of either sufentanil (n =8), etorphine (n = 8), or carfentanil (n = 2). Drug doses used in this study were selected to provide consistency for comparison and are not recommended doses for effective immobilization of wolves. Induction times were similar among groups (11.9 ± 1.0 min). Thirty min after induction, wolves were given either 0.5 mg/kg naloxone hydrochloride plus 0.15 mg/kg yohimbine hydrochloride or saline only intravenously. Arousal times for wolves given naloxone and yohimbine (1.2 ± 0.1 min) were shorter than wolves given saline (35.5 ± 6.4 min). Respiratory rates were similar among the three drug groups (6.9 ± 1.0 breaths/min). One animal given sufentanil then saline was found dead 108 min after induction. Presumptive diagnosis was renarcotization and hypothermia. Results indicated that sufentanil is an effective opioid immobilizing agent for gray wolves.

Retained yolk sacs are common in the domestic chicken and account for considerable morbidity and mortality during late embryonic development and within the first 10 days of life. What is believed to be the first recorded instance of a retained caseous yolk sac and its successful surgical removal from a Burmese python (Python molurus bivittatus) is reported. The snake experienced no post-operative complications and continues to be well 16 mo following surgery.

Inferior brachygnathia in neonatal fawns occurred sporadically over a 10 yr period in a captive herd of white-tailed deer (Odocoileus virginianus) in southern Ontario. Two fawns submitted for necropsy had marked inferior brachygnathia, protruding tongues, and fractured long bones. Radiographs of the limbs revealed longitudinal striations of relatively translucent immature woven bone that caused loss of distinction between medullary cavities and cortices. Microscopically, there was failure of remodelling of the primary spongiosa and filling of the medulla by cone-shaped chondro-osseous cores. The findings supported a diagnosis of osteopetrosis, usually a hereditary disease characterized by absence of marrow cavities as a result of defective bone remodelling. Osteopetrosis has not been reported previously in deer.

Of blood films examined from 170 specimens of 15 Chamaeleo spp. in Tanzania, three C. dilepis had an intracytoplasmic inclusion within monocytes. One of the lizards was maintained in captivity and was sequentially bled over a 55 day period. At 46 days, a second type of inclusion was occasionally seen within monocytes. The lizard became ill and was euthanatized on day 55. All circulating monocytes were found to have either one or both types of inclusions. Histologic examination of multiple tissues demonstrated similar inclusions within macrophages in the spleen and liver. Transmission electron microscopic examination of monocytes revealed the presence of a chlamydia-like organism and pox-like virus. These pathogens have not been reported previously in chameleons, nor has a combined infection of circulating monocytes with these two pathogens been reported for any animal.

Herpesviruses were found associated with epidermal hyperplasia of koi carp (Cyprinus carpio) in northern California (USA). Papillomas were found principally on the caudal regions of the fish including the fins. The grow ths occurred most commonly in the fall and winter among populations of captive carp. Infected epidermal cells were characterized by greatly enlarged nuclei depleted of chromatin but with thickened nuclear membranes. Numerous virions were detected in infected cells. Herpesvirus nucleocapsids in the cell nucleus had a diameter of 109 nm. Virions with envelopes with a diameter of 157 nm were abundant in cytoplasmic vacuoles. The characteristics of the papillomatous growths and the viruses were consistent with descriptions of Herpesvirus cyprini known in koi carp populations in Japan and extends the range of this pathogen to koi carp to North America.