Serum antibodies to strains of avian paramyxovirus and flavivirus were detected in little blue penguins sampled at Port Campbell and Phillip Island, Victoria, Australia. No antibody to Newcastle disease virus (NDV) was detected in 267 sera collected, although one penguin captured for experimental studies had a hemagglutination-inhibition antibody titer of 2⁴ to this virus. Experimental studies showed that the avian paramyxovirus designated APMV-IM and strain V4 of NDV were non-pathogenic for penguins, although the penguins could have been previously infected with these or similar virus strains. A flavivirus designated Saumarez reef virus, and an unnamed virus isolated from ticks on Macquarie Island, Southern Ocean were pathogenic causing disease and mortality in penguins inoculated with the viruses.

Carp pox, a putative viral disease exotic to North America, occurred in golden ide 1 yr after the fish were imported into the United States from the Federal Republic of Germany. The raised, white, plaque-like lesions, which occurred on about 5% of the fish, healed spontaneously and caused no mortality. Electron micrographs showed herpesvirus-like particles associated with lesion specimens; however, no infectious viruses were detected in tests with seven warmwater fish cell lines.

Experimental infections with Yersinia pestis were followed in groups of rock squirrels. Development of coagulopathy and pneumonia were observed in 2–4% and 11–12% of the test animals, respectively. Susceptibility to experimental infection was heterogeneous with some animals surviving inoculation with large numbers of organisms and others succumbing after inoculation with small numbers. Production and longevity of serum antibody titers, as measured by passive hemagglutination tests, were variable as well, and apparently unrelated to dose. The data presented attest to the need for care in interpreting serologic test results for individual animals.

The dot blot assay, modified and adapted for detection of antigens from Vibrio anguillarum in fish tissues, was specific for V. anguillarum and did not react with antigens of V. ordalii, Pseudomonas sp., or Yersinia ruckeri. The blot assay enabled detection of as little as 2.3 ng of a mixture of protein antigens obtained from cell-free extracts of V. anguillarum; it was about 100 times more sensitive than either the indirect fluorescent antibody technique or bacterial isolation for detecting V. anguillarum in fish tissues.

Infection with Sarcocystis (Protozoa: Sarcocystidae) was diagnosed in 130 of 153 (85%) samples of muscle from mule deer around Bozeman, Montana. Three structurally distinct mature and microscopic sarcocysts with characteristic cyst walls were found. Cyst walls of type I sarcocysts were about 2 μm thick and had characteristic inverted tee-shaped villar projections; these cysts were considered to be S. hemionilatrantis Hudkins and Kistner, 1976. Cyst walls in type II sarcocysts were thick-walled (about 7 μm) and their villar projections were 6.7 × 1.1 μm. The core of the villar projections consisted of granular material and some filamentous structures. Bradyzoites were 11.6 × 2.8 μm and were tightly packed in compartments. Cyst walls of type III sarcocysts were also thick-walled (about 9 μm) but the villar projections were 8.5 × 4.7 μm. Bradyzoites were 13 × 3.3 μm and were loosely arranged in compartments.

Isolates of Trichomonas gallinae (Rivolta, 1878) from white-winged doves, Zenaida asiatica (L.), were transferred experimentally to young mourning doves, Zenaida macroura (L.). Twenty-three of 25 mourning doves developed infections with isolates of T. gallinae from 25 white-winged doves. In addition, eight of eight rock doves (Columba livia Gmelin) were infected with duplicate isolates. All infected recipient birds harbored avirulent isolates except for one mourning dove which died from extensive oral lesions. However, repeated attempts using this isolate of T. gallinae to produce lesions in additional recipients were unsuccessful. Despite the findings of this study, it was suggested that future dove management strategies consider the possibility of disease outbreaks involving white-winged doves and susceptible populations of mourning doves.

Five species of helminths were monitored in a population of snowshoe hares (Lepus americanus) near Rochester, Alberta, during 1961-1977. Prevalence of both Obeliscoides cuniculi and Protostrongylus boughtoni among young hares averaged about 50% by age 2 mo, then tended to level off. Prevalence of Taenia pisiformis (cysticerci) and Dirofilaria scapiceps rose more slowly, but continued to increase steadily beyond their mean levels of 8% and 1% at age 2 mo. There were well denned seasonal (within-year) cycles in prevalence of O. cuniculi and P. boughtoni that were generated evidently to a major degree by arrested development of larvae in fall and renewed development in late winter. It was hypothesized that renewed larval development was triggered (in February) in O. cuniculi by the seasonal rise of circulating pituitary gonadotropins, and (in April) in P. boughtoni by the seasonal rise of gonadal androgens and estrogens. Indices to gonadal hormone levels in hares indicated that these increased most rapidly among males, and may have accounted for the higher prevalences of P. boughtoni in males during April-May. Neither T. pisiformis nor D. scapiceps exhibited conspicuous seasonal changes in prevalence. Maximum prevalence of T. pisiformis was attained at about 1 yr of age, whereas D. scapiceps increased among adult snowshoes through age 2 yr before stabilizing. Long-term (between-year) changes in prevalence of O. cuniculi, T. pisiformis, and D. scapiceps were correlated significantly with the cyclic hare population which declined from a peak in fall 1961 to a low in 1965–1966, rose to another peak by fall 1970, and declined again to a low in 1975. There was no detectable time lag between this “10-yr” cycle in hare density and the cycles of parasite prevalence among juveniles (<1 yr of age). Among adult hares, the cycle of O. cuniculi prevalence was likewise synchronous with that of the hare population, but the cycles of D. scapiceps and T. pisiformis lagged by approximately 1 and 2 yr, respectively. This lag in T. pisiformis prevalence was largely inexplicable to us. Our data on P. boughtoni were not suitable for analyses of between-year trends; nor were those for the fifth helminth, Taenia serialis (coenuri), because mean prevalence was less than 1% among both juveniles and adults. An apparent decline in T. serialis after the early 1950's, and its continued scarcity thereafter, paralleled a major change in numbers of one important definitive host—the red fox (Vulpes vulpes). Lighter weights of young hares at age 37–96 days, and of adults and fully grown juveniles, were associated with P. boughtoni infections. There was no demonstrable relationship between snowshoe hare reproductive parameters and helminth parasitism.

Four species of nematodes (Gongylonema pulchrum, Parabronema pecariae, Texi-cospirura turki, and Physocephalus sexalatus) and one species of cestode (Moniezia sp.) comprised the helminth fauna of adult collared peccaries (Tayassu tajacu) from the plains in southern Texas. The community structure of the helminth fauna of peccaries from this region was basically dissimilar to that from the more humid Gulf coastal prairies of southern Texas in (1) composition (by the conspicuous absence of certain species) and (2) relative abundance of shared species. The distributions of each of the three common species of helminths (G. pulchrum, T. turki, and P. sexalatus) were overdispersed. The effects of selected habitat variables operating across host subpopulations (delineated by condition and sex) and of the extrinsic variable of season on the dispersion patterns of the three common species of helminths were examined. The hypothesis that heterogeneity within the host population, rather than across the collective host population, is the main factor generating overdispersion in natural parasite populations was not confirmed for the three common species of helminths. Overdispersion in P. sexalatus resulted from seasonal changes across the collective host population, with the greatest abundances occurring during the cool season. Aggregated abundances of G. pulchrum resulted from variation generated across host sex subpopulations, while the dispersion patterns of T. turki appeared to be unaffected by the habitat variables examined in this study.

Eighty-six adult female white-tailed deer, Odocoileus virginianus (Zimmermann), collected over a 12-mo period in the Texas Edwards Plateau, harbored six species of nematodes (Haemonchus contortus, Gongylonema pulchrum, Oesophagostomum venulosum, Ostertagia ostertagi, Cooperia sp., and Apteragia odocoilei), and two cestodes (Moniezia sp. and Taenia hydatigena). The patterns of distribution of the three common species of gastrointestinal helminths (H. contortus, O. venulosum, and G. pulchrum) were overdispersed. When analyzed for the main and interactive effects of the extrinsic and intrinsic variables of season and physical condition, respectively, aggregated abundances in H. contortus and O. venulosum appeared to result from the main effect of seasonal changes operating over the collective populations of these two species rather than from the intrinsic factor of physical condition operating within selected subpopulations. Abomasal parasite counts do not appear to be a useful index for monitoring herd condition of white-tailed deer from this geographic region.

The larval stage of the winter tick, Dermacentor albipictus, was studied under field conditions in central Alberta, Canada. Larvae ascended vegetation in autumn, possibly in response to photoperiod. Numbers found by flagging increased from early September to early October and decreased gradually to zero by December. Larvae clumped on the tips of vegetation approximately 1–1.5 m off the ground, and did not exhibit a diurnal, vertical migration. Activity was temperature dependent and no obvious preference of vegetation species for ascension was detected. Transmission of larvae to moose was probably facilitated by synchrony of the larval activity period with the moose breeding season in autumn.

The effects of the addition of 25 or 50 ppm fluoride (F), as sodium fluoride (NaF), to the rations of 5-mo-old male white-tailed deer were similar to those observed in domestic cattle fed similar amounts of fluoride. The ingestion of 50 ppm F for 2 yr resulted in the accumulation of over 7,000 ppm F in bone ash. Accumulation of fluoride in antlers was extensive and occurred more rapidly than in skeletal tissue. Fluoride ingestion resulted in lesions on the developing incisors that were similar, but not identical to those seen in other species. Increased molar wear in the deer fed 50 ppm F was minimal, and no gross pathology of the mandible was observed. Only mild hyperostosis of the long bones was evident.

White-tailed deer (Odocoileus virginianus (Zimmermann)) shot within 20 km of the zinc smelters in the Palmerton, Pennsylvania area contained extremely high renal concentrations of cadmium (372 ppm dry weight (dw)) and zinc (600 ppm dw). The deer with the highest renal zinc concentration was shot 4 km from the smelters and had joint lesions similar to those seen in zinc-poisoned horses from the same area. The highest concentrations of lead in both hard and soft tissues were relatively low, 10.9 ppm dw in a sample of teeth, 17.4 ppm dw in a metacarpus, and 4.9 ppm dw in a kidney.