USGS Science⌕ Search

SEARCH · USGS Science

Results for “American Association of Wildlife Veterinarians”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

6 recordsLinked to original sources
USGS2005

Is disease an important mortality factor for Pacific herring?

Marine pelagic forage fishes, including sardines, anchovies, and herring, undergo large oscillations in population abundance. Although over-fishing can have a dramatic impact in reducing population size, this anthropogenic perturbation cannot fully account for all population declines because natural oscillations in marine pelagic fish biomasses occurred prior to the onset of commercial fishing. Among the herring metapopulation in Puget Sound / Straight of Georgia, the mean estimated annual mortality, exclusive of commercial fishing, increased from 20% in the late 1970’s and early 1980’s to 64-87% during 1996-1999. This natural mortality affects primarily the older age cohorts and resulted in recent decreased median ages of adult herring from age 4-6 cohorts to age 2-3 cohorts that die prior to iteroparous spawning. Surveys of wild herring from the region indicate that the protozoan parasite Ichthyophonus sp., is currently ubiquitous among Pacific herring populations in Washington and British Columbia, and prevalence of infection increase directly with herring age, from 12% among juveniles to 58% among the underrepresented age 6+ cohorts. Ichthyophonus can be highly pathogenic to immunologically naïve Pacific herring, causing 80% mortality 2 mo. after exposure in the laboratory. Current laboratory-based studies are underway to determine whether natural Ichthyophonus infections are terminal for the host, and whether these infections account for the decreasing median age of wild Pacific herring populations in recent years.

American Association of Wildlife Veterinarians↗
USGS2008

Comparison of blood aminotransferase methods for assessment of myopathy and hepatopathy in Florida manatees (Trichechus manatus latirostris)

Muscle injury is common in Florida manatees (Trichechus manatus latirostris). Plasma aspartate amino-transferase (AST) is frequently used to assess muscular damage in capture myopathy and traumatic injury. Therefore, accurate measurement of AST and alanine aminotransferase (ALT) is important in managed, free-ranging animals, as well as in those rehabilitating from injury. Activities of these enzymes, however, are usually not increased in manatees with either acute or chronic muscle damage, despite marked increases in plasma creatine kinase activity. It is hypothesized that this absence of response is due to apoenzymes in the blood not detected by commonly used veterinary assays. Addition of coenzyme pyridoxal-5-phosphate (P5P or vitamin B6) should, therefore, result in higher measured enzyme activities. The objective of this study was to determine the most accurate, precise, and diagnostically useful method for aminotransferase measurement in manatees that can be used in veterinary practices and diagnostic laboratories. Additionally, appropriate collection and storage techniques were assessed. The use of an optimized commercial wet chemical assay with 100 ??mol P5P resulted in a positive bias of measured enzyme activities in a healthy population of animals. However, AST and ALT were still much lower than that typically observed in domestic animals and should not be used alone in the assessment of capture myopathy and muscular trauma. Additionally, the dry chemistry analyzer, typically used in clinics, reported significantly higher and less precise AST and ALT activities with poor correlation to those measured with wet chemical methods found in diagnostic laboratories. Therefore, these results cannot be clinically compared. Overall, the optimized wet chemical method was the most precise and diagnostically useful measurement of aminotransferase in samples. Additionally, there was a statistically significant difference between paired serum and plasma measurement, indicating that separate reference intervals should be established for serum and plasma. Finally, storage of these enzymes at -70??C for 1 mo resulted in up to a 25% decrease in enzymatic activity in manatee plasma. Copyright 2008 by American Association of Zoo Veterinarians.

Journal of Zoo and Wildlife Medicine↗
USGS2006

Prevalence of Microsporidia, Cryptosporidium spp., and Giardia spp. in beavers (Castor canadensis) in Massachusetts

Feces from 62 beavers (Castor canadensis) in Massachusetts were examined by fluorescence microscopy (IFA) and polymerase chain reaction (PCR) for Microsporidia species, Cryptosporidium spp., and Giardia spp. between January 2002 and December 2004. PCR-positive specimens were further examined by gene sequencing. Protist parasites were detected in 6.4% of the beavers. All were subadults and kits. Microsporidia species were not detected. Giardia spp. was detected by IFA from four beavers; Cryptosporidium spp. was also detected by IFA from two of these beavers. However, gene sequence data for the ssrRNA gene from these two Cryptosporidium spp.-positive beavers were inconclusive in identifying the species. Nucleotide sequences of the TPI, ssrRNA, and ??-giardin genes for Giardia spp. (deposited in GenBank) indicated that the four beavers were excreting Giardia duodenalis Assemblage B, the zoonotic genotype representing a potential source of waterborne Giardia spp. cysts. Copyright 2006 by American Association of Zoo Veterinarians.

Journal of Zoo and Wildlife Medicine↗
USGS1979

Diet-related die-off of captive black-crowned night herons

Several species of herons, which are top-level consumers in aquatic food chains, have experienced population declines in certain areas o f their normal range (7,13) -- areas in which elevated levels of various environmental pollutants are known to occur. (6) To determine the effects of environmental contaminants on the Ardeidae, a colony of black-crowned night herons (Nycticorax nycticorax) was established in 1972 at the Patuxent Wildlife Research Center. The night heron was selected as the model species because of its widespread occurrence and its ability to survive and reproduce in captivity. Birds for the colony were obtained from either the New York Zoological Park and Dallas Zoo or were wild-caught along the Maryland and Virginia coasts in 1972, 1973, and 1975. This report describes a die-off in the colony following a change in the origina of their food source. The data suggest that the mortality was diet-related, most likely caused by vitamin E deficiency. Excessive dietary thiaminase may have resulted in concurrent thiamine deficiency, but evidence for this is equivocal.

American Association of Zoo Veterinarians, Annual ↗
USGS1986

Use of an inactivated eastern equine encephalitis virus vaccine in cranes

An unprecedented outbreak of fatal eastern equine encephalitis (EEE) virus occurred during the late summer and fall of 1984 in endangered whooping cranes (Grus americana) at the Patuxent Wildlife Research Center, Laurel, Maryland. As part of efforts to prevent future epizootics of EEE. studies were conducted to evaluate the antibody response of cranes following vaccination with a formalin-inactivated EEE virus vaccine. Viral specific neutralizing antibody was elicited in sandhill cranes (Grus canadensis) and whooping cranes following 1M inoculation with the vaccine. Among the 1M-inoculated cranes, peak antibody titers of 1:80 on days 30 to 60 had waned to undetectable levels by days 90 to 120. Although the initial titers were not increased by the first booster dose, the duration of the antibody was extended considerably. Whooping cranes, receiving vaccine 6 months after their first vaccination, developed titers of 1:80 to 1:320 by day 30. At 45 days after the final vaccination, these titers had dropped to 1:10 to 1:160. Cranes with preexisting EEE virus antibody, apparently reflecting natural infection, exhibited an anamnestic response indicated by a rapid increase and sustained high antibody titer. Even though EEE virus vaccine induced neutralizing antibody and produced no adverse side effects, further studies will be required to assess the significance of this response as a strategy for protecting whooping cranes against natural EEE virus infection. The loss of captive whooping cranes to the EEE virus presented a previously unrecognized risk and obstacle to recovery of this species. Not only was, there a setback in the captive breeding and reintroduction program for the whooping crane, but, because of the susceptibility of the species to the EEE virus. establishment of additional crane populations may be more complicated than initially envisioned. However, through continued surveillance, serological monitoring, and vaccination activities, we are confident that the impact of EEE virus on whooping crane recovery can be overcome to the ultimate benefit of this endangered species.

American Association of Zoo Veterinarians, Annual ↗