Outcome of equids with clinical signs of West Nile virus infection and factors associated with death

OBJECTIVE: To determine outcome of equids in the western United States with clinical signs of West Nile virus (WNV) infection and identify factors associated with risk of death in infected equids. DESIGN: Cross-sectional study. ANIMALS: 484 equids in Nebraska and Colorado. PROCEDURE: Owners of 484 equids with laboratory-confirmed West Nile virus infection in Nebraska and Colorado were contacted by telephone, and a questionnaire was used to obtain information on signalment, management, clinical signs, date of disease onset, duration of disease, WNV vaccination status, and health status at the time of the interview. RESULTS: 137 of 482 (28.4%) animals died or were euthanatized. Ataxia, lethargy, muscle fasciculations, and weakness were the most common clinical signs of disease. Animals > or = 3 years old were more likely to die than were animals < or = 2 years old. Unvaccinated equids were twice as likely to die as were animals that had been vaccinated at least once prior to the onset of disease. Animals that were recumbent and unable to rise were 78 times as likely to die as were animals that never lost the ability to rise. Females were 2.9 times as likely to die as males. Two hundred seventy-one of 339 (79.9%) animals that survived recovered fully; mean duration of disease for these animals was 22.3 days. CONCLUSIONS AND CLINICAL RELEVANCE: Among equids with WNV infection, age, vaccination status, an inability to rise, and sex were associated with the risk of death.     

Antigen challenge increases adherence of circulating neutrophils in horses with chronic obstructive pulmonary disease

Activation of circulating neutrophils has been observed following challenge of horses with chronic obstructive pulmonary disease (COPD) and may facilitate the accumulation of these cells in the airways. In this study, no significant difference was observed between adherence to protein coated plastic of blood neutrophils from asymptomatic COPD-susceptible and normal horses stimulated by the mediators PAF, human recombinant (hr)IL-8 and hrC5a. Twenty-four hours after the start of a 7 h antigen challenge, adherence of unstimulated neutrophils from COPD-susceptible horses increased from 2.5 (0.5-4.1)% and 3.4 (0.6-6.6)% to 19.6 (16.9-20.3)% and 21.8 (10.6-23.1)% adherence for cells in medium containing 0.1% or 0.2% BSA, respectively; (median [range]; n = 4). Adherence of cells from normal horses remained unchanged. Addition of an anti-CD18 monoclonal antibody, H20A, inhibited the increase in adherence at 24 h by 96 (45-100)%, n = 3. The percentage of neutrophils in bronchoalveolar lavage fluid at 24 h increased from 1 (0-2) to 80 (65-94), (median (range), n = 4). These results suggest that antigen challenge results in exposure of circulating equine neutrophils to one or more factors that prime, or activate, these cells, which may enhance their recruitment to the lungs. Inhibition of circulating neutrophil activation may therefore represent a therapeutic target.     

乔科型藏羊遗传资源保护及制种供种体系建设思路

作者通过调查乔科型藏羊遗传资源现状,发现乔科型藏羊纯种数量当前仍有不断下降的风险,为了避免乔科型藏羊种群数量不断减少,作者分析了乔科型藏羊种质资源的优良特性,总结了开展乔科型藏羊遗传资源保护的意义,提出了乔科型藏羊遗传资源保护及制种供种体系建设的思路,并提出了建议。     

Further Studies on the Use of Nicotine to Promote Leanness in Pigs

Four experiments using weight gain, feed efficiency and carcass analysis criteria were conducted with 148 pigs to determine the effects of feeding nicotine sulfate at various levels on protein and fat deposition. A level of 5 p.p.m. of nicotine sulfate in the ration fed to pigs from weaning until market weight significantly decreased (P<.05) the depth of loin fat in two of three experiments in which it was tested and slightly increased the carcass protein: fat ratio in all experiments. A level of 20 p.p.m. was as effective as 5 p.p.m. but higher levels of 40 and 80 p.p.m. had no effect on carcass quality. The fat content of the livers of pigs fed 5 p.p.m. of nicotine sulfate was found to be 8 to 10 per cent higher than that of controls in the two experiments in which it was measured. Higher levels of nicotine had little or no effect on liver lipids. Plasma cholesterol levels of pigs were not increased by the feeding of nicotine sulfate at levels of 5, 20 and 80 p.p.m.     

Biological characterisation of Australian isolates of chicken anaemia agent

Three Australian isolates of chicken anaemia agent (CAA) resisted treatment at 70 degrees C for 5 min and chloroform treatment. Although minor antigenic differences were detected using monoclonal antibodies to CAA, the Australian isolates were indistinguishable from the reference Cux-1 and Gifu-1 isolates in cross-immunofluorescence and cross-neutralisation tests employing polyclonal chicken antiserums. The Australian viruses were pathogenic for intramuscularly inoculated 1-day-old SPF chicks, but were less pathogenic for 7-day-old chicks. Thus the Australian isolates of CAA did not differ significantly in these properties from previously characterised CAA isolates from other continents.     

Characteristics of hollow-bearing trees occupied by arboreal marsupials in the montane ash forests of the Central Highlands of Victoria, south-east Australia

A total of 1125 hollow-bearing trees was observed for the presence of arboreal marsupials in the montane ash forests of the Central Highlands of Victoria, south-east Australia. Different species of arboreal marsupials exhibited preferences for hollow-bearing trees with different characteristics. Gymnobelideus leadbeateri (Leadbeater's possum) selected short, fat trees with numerous holes and a large quantity of dense surrounding vegetation. Very large hollow-bearing trees were favoured as nest sites by Petauroides volans. Petaurus breviceps preferred trees with a large number of fissures, whereas trees favoured by Antechinus stuartii were tall and thin. Trees selected as nest sites by Trichosurus caninus were typically short and fat with few holes. Our results provide evidence of resource partitioning of hollow-bearing trees amongst arboreal marsupials. Clear-felling of montane ash forest on an 80–120-year rotation will have a highly detrimental effect on arboreal marsupials by substantially reducing the number and range of types of hollow-bearing trees required to support the complete diversity of species. The 80–120-year interval between logging operations will result in trees being harvested well before they develop characteristics which make them suitable nest sites for arboreal marsupials.