Age-dependent changes in plasma and brain cholinesterase (ChE) activity were characterized in two altricial passerine species: eastern bluebirds (Sialia sialis) and European starlings (Sturnus vulgaris). Plasma acetylcholinesterase (AChE) activity declined rapidly immediately after hatching, while plasma butyrylcholinesterase (BChE) activity increased throughout the nestling period. These patterns continued after birds fledged, since the BChE : AChE ratio was higher in adult birds than fledglings. This is the first confirmation of age-dependent changes in plasma ChE activity in altricial species. Total plasma ChE activity increased with age in both species, which is the reverse of results previously reported for several precocial species. Brain ChE activity increased with age in both species, and did not reach asymptotic levels before young fledged. This corresponded with patterns previously documented in European starlings and three other altricial species. We propose that age and degree of precocity in young birds must be considered when examining sensitivity or evaluating field exposure of birds to ChE-inhibiting compounds.

Several features related to waterfowl carcasses were studied at Eyebrow Lake, Saskatchewan, Canada, during a botulism epizootic in the summer of 1989. Dummy carcasses, constructed by stretching duck skins over wooden forms, were used to assess the reaction of waterbirds to carcasses. There was no significant difference in the number of American coots, ducks, grebes, or total birds present when dummy carcasses were or were not present. Only one of 42 freshly-dead bird carcasses marked and observed twice each day was removed by a scavenger prior to the development of large maggots. Maggots developed in all carcasses and were visible externally a mean of 3.9 days after placement of the carcasses. The effectiveness of carcass collection and disposal operations was tested by marking carcasses on the day prior to two scheduled cleanups. Only 32% of marked carcasses were recovered. Large carcasses and carcasses on or near islands were recovered at a higher frequency than were small carcasses and carcasses not near islands, respectively.

A study on descriptive epizootiology of the viral necrotising hepatitis of hares, European brown hare syndrome (EBHS) was conducted in Sweden. Two thousand eight hundred eighteen hares were necropsied between 1980 and 1989. European brown hare syndrome was diagnosed histologically in 234 (14%) of 1644 European brown hares (Lepus europaeus) and 26 (3%) of 958 varying hares (Lepus timidus). Most cases occurred in October, November, and December. In 1980, the first cases were recorded on the island Gotland and in 1981 EBHS occurred on the mainland in the south of Sweden. In the following years it spread northward up to the Nordic limit (Limes norrlandicus), which marks the transition of climate, topography, fauna and flora, between central Sweden and Norrland. By 1989 EBHS was restricted to the southern terrain, overlapping the distribution of the population of European brown hares, and it occurred in 23.2% of the hares received for post-mortem examination at the National Veterinary Institute of Sweden.

Immune function in harbor seal mothers and their pups during lactation was studied on Sable Island, Nova Scotia, Canada, during the springs of 1989 and 1990. Methods included total white blood cell and differential counts, a Protein A enzyme linked immunosorbent assay (ELISA) for total immunoglobulin G (IgG) quantification, and functionality testing of lymphocytes in vitro using the T-cell mitogen concanavalin A (ConA). Lymphocyte functionality and total IgG levels were reduced in the mothers at the end of lactation, suggesting a reduction in immune function, possibly as a result of the stress of fasting, or hormonal changes associated with lactation and estrus. By contrast, lymphocyte functionality and total IgG levels in pups were low at birth and higher at the end of lactation. Pups at birth and females late in lactation may therefore be more susceptible to infection by viral and bacterial agents. This study represents the first broad examination of immune function in a free-ranging pinniped population.

Peripheral blood neutrophils from Rocky Mountain bighorn sheep (Ovis canadensis canadensis) and domestic sheep were exposed to culture supernatants from Pasteurella haemolytica isolates recovered from these two sheep species. Six culture supernatants from bighorn sheep isolates and two from domestic sheep isolates were tested for cytotoxicity as determined by the release of lactate dehydrogenase. Two of the bacterial culture supernatants from bighorn sheep were not cytotoxic, while the other four bighorn sheep culture supernatants were effective cytotoxins on both bighorn (>95% cell death at 150 μg of cytotoxin) and domestic sheep neutrophils (55 to 95% cell death at 150 μg of cytotoxin). Two culture supernatants of P. haemolytica from domestic sheep were effective cytotoxins on both bighorn (>95% cell death at 150 μg of cytotoxin) and domestic sheep (70 to 75% cell death at 150 μg of cytotoxin) neutrophils. Potency of cytotoxins derived from P. haemolytica isolates from bighorn sheep was three to seven-fold higher when tested with bighorn sheep neutrophils as compared to domestic sheep neutrophils. Cytotoxins derived from P. haemolytica isolates from domestic sheep were five to six-fold more potent when tested with bighorn sheep neutrophils than when domestic sheep cells were used.

Serum samples obtained from 38 free-ranging Florida panthers (Felis concolor coryi) in southern Florida, March 1978 through February 1991, were tested for antibodies against eight bacterial, parasitic, and viral disease agents. Sera were positive for antibodies against feline panleukopenia virus (FPV) (78%), feline calicivirus (56%), feline immunodeficiency virus/puma lentivirus (37%), feline enteric coronavirus/feline infectious peritonitis virus (19%), and Toxoplasma gondii (9%). All samples were seronegative for Brucella spp., feline rhinotracheitis virus, and pseudorabies virus. In addition, all the animals tested were negative for feline leukemia virus p27 antigen as determined by enzyme-linked immunosorbent assay. Feline panleukopenia virus was considered to be a potentially significant disease agent; FPV antibodies occurred in the highest prevalences in older age classes (P = 0.027) and in panthers living in the dense mixed hardwood swamps in the western portion of their range compared to the open cypress and sawgrass prairies to the east (P = 0.096). Because <50 animals remain in this relict population and the probable resultant depression of genetic diversity and lowered disease resistance, FPV or other disease agents could contribute to the extinction of this endangered subspecies.

In 1989, herpesviruses were isolated from nasal swabs taken from two peninsular bighorn sheep (Ovis canadensis cremnobates) in the Anza-Borrego Desert State Park, San Diego County, California (USA). Using restriction endonuclease analysis (REA) with Pst1 enzyme, each isolate was found to be similar to the Cooper strain of infectious bovine rhinotracheitis virus (IBRV). The REA patterns of the two herpesviruses from bighorn sheep were typical of either field strains or vaccine strains of IBRV commonly associated with cattle in the USA.

Giemsa-stained peripheral blood films from 9 of 50 flap-necked chameleons, Chamaeleo dilepis, and 1 of 18 Fischer’s chameleons, Bradypodion fischeri, collected in Tanzania had intraerythrocytic inclusions. In C. dilepis, acidophilic inclusions were associated with the albuminoid vacuoles reported in typical pirhemocytonosis of saurians. Under transmission electron microscopy, the acidophilic inclusions were aggregations of partially or completely formed viral particles consistent with those of the family Iridoviridae. Enveloped viral particles were 140 to 180 nm in diameter, with a mean of 159 nm (SD, 12). Albuminoid vacuoles were not seen in the B. fischeri infection, in which erythrocytes contained multiple acidophilic inclusions of variable shape. Viral particles in B. fischeri were 156.3 to 200.0 nm in diameter; the mean was 180 nm (SD, 18). This represents the first confirmation of the viral identity of pirhemocyton in a lizard. We recommend that the epithet pirhemocyton no longer be used as a generic name under the International Code of Zoological Nomenclature, and that future reports of the etiologic agent refer to it as Lizard Erythrocytic Virus.

During a special two-day hunt (11, 12 November 1989) in Saint Croix State Park, Minnesota (USA), one side of the neck for each of 146 white-tailed deer (Odocoileus virginianus) was examined for ticks. Of the 5,442 ticks collected, 90% (4,893) were the winter tick, Dermacentor albipictus, and 10% (549) were the deer tick, Ixodes dammini, the primary vector of the causative agent of Lyme disease, Borrelia burgdorferi. Adult males had the greatest frequency of infestation of either D. albipictus (100%) or I. dammini (88%) and had on average more ticks, compared to other deer. Based on an examination of midgut material from 435 I. dammini by polyclonal antibody analysis, spirochetes were observed in 22% of the ticks. Species-specific monoclonal antibody analysis of the spirochetes confirmed that the bacteria were B. burgdorferi.

Three morphologically distinct types of sarcocysts (I, II, and III) were identified by light microscopy in tongues from 403 white-tailed deer (Odocoileus virginianus) collected in Florida (USA) over a 7-yr-period. Based on electron microscopy of representative examples of these sarcocysts, there were four distinctive wall structures. We concluded that one of these (Type I) was representative of Sarcocystis odocoileocanis and another (Type III) was representative of an unnamed species previously described from white-tailed deer in Montana. Type II could be divided further into two forms (IIA and IIB) that may represent two undescribed species or developmental stages of the same species. Sarcocystis odoi, another previously recognized sarcosporidian from white-tailed deer, was not found. Sarcocysts of Types I and II were distributed nonrandomly in tongue muscle, being more common in the basal portion, whereas Type III was distributed randomly throughout the tongue. Single infections (one of the three types) accounted for 63% of the infected deer, while double infections occurred in 28% and triple infections in 4%. Types I and II were found in deer throughout the state, but Type III occurred only in deer from southern Florida. In 1988 and 89, the statewide prevalences for Types I, II, and III were 57, 20, and 6%, respectively. Prevalences of Type I ranged from 94% in the panhandle region (northern Florida) to 34% in the southern part of the state. Prevalences of all three types increased with age.

Four Rocky Mountain bighorn sheep (Ovis canadensis canadensis) were experimentally inoculated with Psoroptes sp. of bighorn sheep origin by placing approximately 50 mites into each ear. Two sheep developed reproducing mite colonies and lesions consisting of alopecia, and exudative dermatitis with scabs on ears, face and neck. Three months after inoculation, all four sheep were treated with an in-feed formulation of ivermectin at a dosage of 1 mg/kg of body weight in a pelleted ration daily for seven consecutive days. Mites could not be detected on any of the sheep 1, 2, or 3 mo after treatment, and lesions on the affected sheep resolved within 6 to 8 wk after treatment. Thus, under these conditions, ivermectin was completely effective in eliminating the mites; it also was palatable and nontoxic. Use of ivermectin in pelleted feed for field treatment of psoroptic mange is encouraged.

Sex- and age-specific fecal lungworm (Protostrongylus spp.) larvae concentrations in Rocky Mountain bighorn sheep (Ovis canadensis canadensis) from the Cinnabar Winter Range in southwestern Montana were determined. All 228 fecal samples collected from bighorn sheep of known sex and age class from November to April, 1984 to 1987 contained first-stage lungworm larvae. Fecal lungworm concentrations of ewes and rams declined significantly from late fall through early spring, whereas number of lungworms in lamb feces increased as winter progressed.

Mammary secretions from two bowhead whale (Balaena mysticetus L.) females carrying near-term fetuses were analyzed for dry matter, ash, protein, fat, carbohydrate and energy content. Protein values ranged from 75.9% to 97.3% of dry matter. Fat ranged from 0.6% to 9.1 % of dry matter. A protein corresponding to beta-lactoglobulin on gel filtration chromatography was the predominant whey protein. Neutralizing antibodies to nine caliciviruses were detected in one sample. Composition of these two samples differs from previous reports for cetacean milk, perhaps due to the stage of lactation.

Fat soluble vitamins E and A (quantified as α-tocopherol and all-trans retinol, respectively) were measured in plasma samples from 274 captive cranes from four institutions and five free-ranging birds. Ages ranged from 4 mo to 80 yr, and all 15 crane species were represented. Captive cranes had a mean ± standard error (SE) of 6.57 ± 0.82 μg/ml α-tocopherol; migrating greater sandhill cranes (Grus canadenis tabida) had a plasma concentration of 3.71 ± 0.22 μg/ml. Sex and age differences were not significant, but crane species that evolved in temperate habitats had higher circulating levels of α-tocopherol than tropical or subtropical species. Mean ± SE retinol values were 0.69 ± 0.05 μg/ml in captive cranes, and 0.66 ± 0.08 μg/ml in free-ranging cranes; values did not differ significantly by sex, age, or species. Dietary vitamin E concentrations were significantly correlated with plasma α-tocopherol levels in a logarithmic relationship. Dietary selenium at 0.5 mg/kg was associated with decreased circulating a-tocopherol concentrations.

In 1988 and 1989, thousands of harbor seals (Phoca vitulina) died in the North Sea from phocine distemper infection. The morphology of thyroid glands from 40 harbor seals found dead on the North Sea coastlines of Schleswig-Holstein, Federal Republic of Germany, during an epizootic of phocine distemper, was compared with the morphology of thyroid glands from five healthy harbor seals collected in Iceland. Thyroid glands from seven harbor porpoises (Phocoena phocoena) found dead in 1990 on the North Sea coastlines also were evaluated. Colloid depletion and fibrosis were found in the thyroid glands of harbor seals which died during the epizootic, but not in animals from Iceland. Thyroid glands of the porpoises showed similar lesions, but to a lesser degree, than those observed in the North Sea seals.

In 1990, 74 dusky dolphins (Lagenorhynchus obscurus) and 10 Burmeister's porpoises (Phocoena spinipinnis) were examined for the presence of hyperpigmented marks and pinhole lesions on the skin (tattoo lesions) at the fishing terminal of Pucusana, central Peru. Prevalences of tattoo lesions were 8.1% and 30% in the dolphins and porpoises, respectively. In-tracytoplasmic poxviruses were demonstrated by transmission electron microscopy in ultrathin sections of three of eight samples of infected epidermis from both species. The reason for the negative results in others is unclear but may be related to stages of infection with low virus density or even incorrect classification of some lesions as genuine viral tattoos. An irregular arrangement of tubules on the outer viral membrane, similar to those in orthopoxviruses, was visible in negative contrast preparations for P. spinipinnis. This is the first record of poxvirus in porpoises (Phocoenidae) and also the first report for dusky dolphins, and generally for cetaceans of the southern hemisphere.

The first case of phocine distemper in a seal from Canadian waters and the first case of clinical phocine distemper in a harp seal, Phoca groenlandica, is reported. A two-month-old female harp seal stranded on Prince Edward Island in May 1991. Significant clinical findings were lethargy and severe conjunctivitis. Pulmonary congestion was the main necropsy finding, and histological lesions included diffuse demyelinating nonsuppurative encephalitis and mild multifocal interstitial pneumonia. Acidophilic intracytoplasmic and intranuclear inclusions were present in cerebral neurons and astrocytes. Immunoperoxidase staining confirmed phocine distemper virus (PDV) antigen in the cytoplasm and nuclei of neurons, bronchiolar gland epithelium and transitional epithelium of the bladder. Infectivity titers of canine di;-temper virus (CDV) (Onderstpoort strain) and a morbillivirus isolated from a grey seal were significantly reduced by serum from the harp seal.

Brucellosis was studied opportunistically in bison (Bison bison) in the free-ranging Jackson herd of approximately 120 in Teton County, Wyoming (USA) in March 1989. Recent abortion was diagnosed in a 2-yr-old cow and Brucella abortus biovar 1 was isolated from vaginal discharge, uterine contents, uterus, and supramammary lymph nodes. Endometritis was characterized by lymphoplasmacytic infiltrates in the lamina propria and neutrophils in uterine glands and within necrotic debris and exudate in the uterine lumen. A 5-yr-old bull had diffuse lymphoplasmacytic infiltrates in epididymis and accessory sex glands; B. abortus was isolated from seminal vesicle and ampulla. Twenty-seven (77%) of 35 bison tested from 1989 to 1990 were serologically positive or suspect on tests for Brucella antibodies. We report the occurrence of abortion due to brucellosis in free-ranging bison in the Jackson herd, suggest that bison in this herd are capable of transmitting brucellosis to other susceptible hosts, and report the first confirmation of brucellosis in this herd.

Twenty-eight wild rats were live-trapped in central Iowa (USA) to estimate the prevalence of the cilia-associated respiratory (CAR) bacillus. Both light and electron microscopy were used to look for the Gram-negative, filamentous bacterium among cilia in tracheal and lung tissue sections. The organism was observed in the trachea of 20 rats with chronic respiratory disease and in the trachea of three of eight normal rats. Therefore, the organism appears to be common among wild rats in central Iowa.

Yersinia enterocolitica serotype 0:5,27 biotype 2 was isolated from the intestinal contents of a common garter snake (Thamnophis sirtalis). The isolate possessed virulence associated phenotypes in all tests conducted. It was susceptible to amikacin, ampicillin/sulbactam, aztreonam, cefoperazone, cefotaxime, ceftazidime, ceftriaxone, cefuroxime, ciprofloxacin, gentamicin, imipenem, mezlocillin, norfloxacin, piperacillin, ticarcillin/clavulanic acid, trimethoprim-sulfamethoxazole, tobramycin, chloramphenicol and tetracycline. The isolate harbored the virulence plasmid.

An enzyme-linked immunosorbent assay for anthrax antibody in white-tailed deer (Odocoileus virginianus) was developed and used to evaluate a vaccination study and compare sera from hunter-killed deer in anthrax endemic and non-endemic areas. Deer subcutaneously vaccinated with anthrax avirulent spore vaccine developed specific antibody to protective antigen (PA) which was significantly higher than the non-vaccinated controls at 30, 60, 90, and 240 days post-vaccination. There was no difference between the levels of antibody to PA between deer in anthrax endemic and non-endemic areas.

Demodicosis was diagnosed in five black bears (Ursus americanus) from north-central Florida. The first bear examined, a 5-yr-old male, had severe alopecia except for the dorsal neck, paws, and ears. The skin was characterized by moderate orthokeratotic hyperkeratosis, and mild to moderate follicular hyperkeratosis. Superficial dermatitis, follicular pustules, and epidermal pustules were present, but rare. Specimens of Demodex sp. were seen most commonly within hair follicles devoid of hair and at the infundibulum of sebaceous glands. Four additional bears from the same area also had some degree of alopecia and skin scrapings were positive for Demodex sp. This mite may be common, although its prevalence is not known.

Demodex spp. mites were seen in skin sections of 5 of 53 raccoons (Procyon lotor) necropsied on Parramore Island, Virginia (USA). In all infections, mites were present in the skin over the lower legs; in one raccoon they also were located in a follicle of a vibrissa. None of the raccoons had Demodex-related gross lesions. Histopathologically, minimal lesions were seen in the affected follicles. This is the first documentation of Demodex spp. in raccoons.

Duration of attachment was determined for the chigger, Eutrombicula lipovskyana in mite pockets of the phrynosomatid lizard, Sceloporus jarrovii from Arizona. Eutrombicula lipovskyana remained attached in mite pockets for as long as 52 days. Infestations in other body areas were of shorter duration. The mite Geckobiella texana was also found to infest S. jarrovii.

Three captive banded rock rattlesnakes (Crotalus lepidus klauberi) died at Taronga Zoo, Sydney, Australia, between 1984 and 1987 with similar lesions in each case. Grossly, the liver and kidneys had multiple grey, fleshy nodules replacing much of the parenchyma. Histologically, these lesions were massive accumulations of yeast-like organisms, located mainly within macrophages in capillaries and sinusoids. There was little other inflammatory reaction. Organisms also were seen in the muscle and adventitial coats of the intestine, in the spleen, pancreas, brain, lungs, ovary, and fat body. Apparent budding was observed in fresh smears, and the organisms stained Gram-positive and periodic acid-Schiff positive but failed to grow on routine fungal media. Based on transmission electron microscopy, the organisms were typical yeast cells with thick, apparently single-layered cell walls showing evidence of enteroblastic proliferation. Two of the snakes had concurrent bacterial infections.

A female prairie rattlesnake (Crotalus viridis viridis) was gastric intubated with 250 tetrathyridia of Mesocestoides sp. The snake was killed 12 wk postinfection; a portion of the liver was examined histologically for evidence of tetrathyridia. Five tetrathyridia were seen in two hepatic portal triad vessels. We propose that a blood-borne metastasis of tetrathyridia in reptiles and rodents may occur.

Three Tsushima leopard cats (Felis bengalensis euptilura) in Japan were collected as road kills. Three species of trematodes (Pharyngostomum cordatum, Paragonimus sp. and Dicrocoeliidae gn. sp.), one species of cestode (Spirometra erinacei) and nine species of nematodes (Arthrostoma hunanensis, Uncinaria felidis, Uncinaria sp., Ancylostoma tubaeforme, Molineus springsmithi, Toxocara cati, Capillaria aerophila, Capillaria feliscati, and Capillaria sp.) were found. Among these helminths, Arthrostoma hunanensis, Uncinaria spp., and Molineus springsmithi have not been reported previously in Japanese domestic cats.

Efficacy of cleaning Baermann apparati was evaluated to determine if larvae are retained on glassware after evaluating white-tailed deer (Odocoileus virginianus) fecal samples containing Parelaphostrongylus tenuis. Residual P. tenuis larvae were recovered from 7 (11.7%) of 60 Baermann apparati cleaned with soap and tap water. Of 295 moose (Alces alces) fecal samples collected in central and northern Maine, only one contained protostrongylid larvae. Our data do not support the hypothesis that recent increases in Maine’s moose population can be attributed to moose becoming a suitable host to P. tenuis.

The eyes from 103 hunter-killed white-tailed deer (Odocoileus virginianus), and 19 mule deer (O. hemionus) killed between 28 November to 14 December 1991 from Wain-wright, Alberta were examined for Thelazia spp. One immature male and two immature female Thelazia skrjabini were collected from beneath the third eyelid of one adult female O. virginianus. This is the first report of T. skrjabini in a member of the Cervidae.

Cryptosporidiosis, previously unreported in cotton rats (Sigmodon hispidus), was observed in one of nine cotton rats from Pryor, Oklahoma (USA). Infection was confined to the large intestine. Microscopically, numerous cryptosporidians measuring 2 to 3 μm in diameter were intimately associated with the luminal surface of colonic and rectal mucosae. The affected lamina propria of the large intestine was diffusely infiltrated by eosinophils, lymphocytes and macrophages. Ultrastructurally, numerous trophozoites and a single schizont were observed. Microvilli were displaced by the presence of cryptosporidians at the attachment site.

Three hundred and seventy-five acanthocephalans, Moniliformis clarki, were removed from the small and large intestines of a gray squirrel from Arkansas County, Arkansas (USA). This is the first report of M. clarki from Arkansas. Enteric lesions, including distension, perforating ulcers, enteritis, crypt hypertrophy, goblet cell hyperplasia, and occlusions of the intestinal tract were observed, indicating the pathogenic potential of this parasite.

A zoo-bred Himalayan red panda (Ailurus fulgens fulgens) was diagnosed as a presumptive intersex on clinical examination at 4-mo-of-age. The phenotype was predominately female but showed a large anogenital distance and bilateral ischial swellings. Based on cytogenetic evaluation, the karyotype was mos35,X/36,XY, with 50% of each cell type. A grossly normal uterus and oviducts were seen with laparoscopic examination, while the gonads were smooth-surfaced, with a ramifying vascular pattern. On histopathologic examination the bulk of the gonads consisted of clumps of poorly differentiated cells, with just a thin rim of ovarian tissue under the region covered by the fimbriae of the oviduct.

A total of 15 immobilizations were performed on 12 common genets (Genetta genetta) with a combination of ketamine hydrochloride (KE) and xylazine hydrochloride (XY). Ten immobilizations were successful using a single mean administration of 5.7 mg/kg (SD = 1.7) KE and 9.8 mg/kg (SD = 2.9) XY; five immobilizations required supplemental doses that averaged 3.4 mg/kg KE and 1.9 mg/kg XY. Initial doses of 7 mg/kg KE and 10 mg/kg XY are recomended to successfully immobilize genets. Mean induction time and arousal time were 8 min (SD = 4, n = 10) and 113 min (SD = 57, n = 9), respectively. A combination of KE and XY appears to be an effective and safe immobilizing agent for common genets.

Two red-tailed hawks (Buteo jamaicensis), found near Deltaville, Virginia (USA), were evaluated because of inability to use a wing. Results of needle electromyographic studies of the affected wing muscles in both hawks were compatible with denervation. On euthanasia, one hawk had extensive axon and myelin loss with multifocal perivascular lymphocytic inflammation of its brachial plexus and radial nerve. Demyelination and axon loss in the dorsal white matter of the spinal cord on the affected side also were found at the origin of the brachial plexus. The other hawk's wing had not returned to functional status >2 yr after injury.