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131.
A 4-year-old female spayed domestic ferret (Mustela putorius furo) presented with a history of vomiting over 24 hours. On physical examination, a significantly enlarged, firm spleen was palpated. Abdominal radiographs and abdominal ultrasound were suggestive of a splenic torsion or splenic infarction. An exploratory laparotomy confirmed the initial diagnosis and splenectomy was performed using a vessel sealing device. Histologic evaluation and culture of the spleen were consistent with primary torsion without evidence of infection or neoplasia. The patient recovered from surgery without complications. Based on a literature search, this is the first report of the clinical diagnosis and successful surgical treatment of a primary splenic torsion in a ferret. Although it appears to be a rare and potentially life-threatening disease in ferrets, splenic torsion should be considered as a differential diagnosis in ferrets that present with non-specific signs and a palpably enlarged spleen.  相似文献   
132.
More research is required to validate and refine natural abundance stable isotope ratio techniques as a tool for the investigation of the feeding ecology of soil animals and trophic relations in soil food webs. Isotope ratios of C (δ13C) and N (δ15N) were measured in herbivorous and detritivorous invertebrate groups, namely lumbricid earthworms (7 species), enchytraeid worms (3 species), slugs (3 taxa), and their potential food sources in an arable system. Intrapopulation δ15N variation in the slug Deroceras reticulatum (n=52) was large (range 4.2‰), possibly reflecting spatial variability in the food sources. Significant correlations between C:N ratios and isotope ratios in earthworms suggest that factors other than feeding may influence isotopic patterns. One enchytraeid species, Enchytraeus buchholzi, was enriched in 13C and strongly depleted in 15N compared to all other groups. Invertebrates formed a continuum when considered in relation to C and N separately, but fell into two distinct groups on the basis of combined C and N isotope ratios. The less enriched group represents herbivorous and litter-feeding species, while the more enriched group represents soil feeders. It is concluded that δ13C measurements could provide a means of assigning separate baseline δ15N values to primary and secondary decomposers, which in turn could improve the inference of higher trophic levels, omnivory and intraguild predation.  相似文献   
133.
Bastian  Olaf 《Landscape Ecology》2001,16(8):757-766
Contemporary landscape ecology is not unified at all.There are historical, geographical and biological reasons for the lack of unification, as well as differences between science and application. The search for a unified theory of landscape ecology should consider previous concepts such as ‘landscape diagnosis’ and ‘landscape functions’ which were elaborated in Central Europe. Because of the various aspects in a landscape (components, processes, relations), landscape ecology should be regarded as a multidisciplinary, better a transdisciplinary, science where different views and approaches are involved in a holistic manner. The principle of complementarity is helpful to understand and describe the landscape. As a crucial step, the transformation of natural science categories to categories of the human society is brought out. This is realized by land(scape) evaluation and by the elaboration of goals (visions) of landscape development.This revised version was published online in May 2005 with corrections to the Cover Date.  相似文献   
134.
Seventy-six dogs with clinical acquired atrioventricular valvular disease were evaluated to determine the efficacy of pimobendan (n=41) versus benazepril hydrochloride (n=35) in a randomized, positive-controlled, multicenter study. The study was divided into 56-day and long-term evaluation periods. In a subgroup of dogs with concurrent furosemide treatment (pimobendan [n=31], benazepril [n=25]), the Heart Insufficiency Score improved in favor of pimobendan (P=0.0011), equating to a superior overall efficacy rating (P<0.0001) at day 56. Long-term median survival (i.e., death or treatment failure) for dogs receiving pimobendan was 415 days versus 128 days for dogs not on pimobendan (P=0.0022).  相似文献   
135.
136.
We sampled 1091 Icelandic broiler flocks at slaughter from May 2001 to December 2003 to determine the prevalence of, and investigate risk factors for the presence of, Campylobacter spp. at the flock level. Approximately 15% of the flocks were positive for Campylobacter spp.; most (95%) of the infected flocks being raised during the months of April–September. Based on the data from the latter months, and using multivariable logistic regression with random effects for herd, we found that the odds of a flock being positive for Campylobacter spp. increased with age and flock size. Additionally, vertical ventilation systems were strongly associated with positive flocks (OR = 5.3). After controlling for these variables, we found no evidence of an effect of: year; company; Campylobacter being carried over from one flock to the next; time interval between flocks; using (at the hatcheries) eggs laid on the floor; density of bird housing, or the number of catch lots a flock was divided into for slaughtering purposes on the risk of a Campylobacter-positive flock.  相似文献   
137.
The objectives of the study were to quantify the levels of badger exposure for cattle and to test the hypothesis that increased badger exposure does not increase the risk of bovine tuberculosis (BTB) in a herd. Information that became available from the targeted removal of badgers over the study period, and from a badger-removal project in county Kilkenny, during 1996-1999 was used. The specific location of cattle within each farm, and the length of time that cattle spent in each farm field during the grazing season, and in the barnyard during winter, was used to build an exposure coefficient to quantify the amount of badger exposure that cattle encountered either on pasture or in the barn. The study design was a matched case-control study in which the control herds were selected using incidence density sampling. During the 4-year study period, 543 badgers were removed and of these 96 badgers were classified as tuberculosis positive; 96 BTB herd breakdowns occurred. There was a significant association between case herds and having a higher badger sett exposure coefficient during 1996-1998. No significant association between case herds and having a higher exposure coefficient based on the number of badgers, or the number of tuberculous badgers, during September 1997-December 1999 was found.  相似文献   
138.
In traditional cattle systems in the tropics, the milk produced is generally shared between the calf and the cattle keeper. This literature review evaluates the socio-economic aspects related to milk production and milk use in traditional cattle systems and identifies the best strategies of milk allocation in order to improve food security and maximise income. The available literature indicates that milk, in terms of economic, social and subsistence value, is more valuable than meat. Thus, under the conditions that characterise traditional cattle systems in the tropics, it is appropriate to have a higher milk offtake at the expense of calf growth. This review also found that certain management practices, such as restricted suckling, can be useful to minimise mortality of calves, while improving milk offtake for human consumption.  相似文献   
139.
Canine leptospirosis has been described as having re-emerged in North America around the mid-1990s, with a change in the epidemiology of the infecting serovars responsible for the disease emergence. A retrospective case-control study was conducted to examine the re-emergence of seroprevalent cases of canine leptospirosis in Ontario using serology submission records from 1406 dogs from January 1, 1998 to December 31, 2006. The data collected [results of the microscopic agglutination test (MAT), veterinary clinic postal code, age, sex, neutering status, and breed] were analyzed by multivariable logistic regression, generalized linear mixed modeling, and Cochran-Armitage test for trends in proportions. Dogs in urban areas appeared to be at significantly higher risk than dogs in rural areas for the entire study period [odds ratio (OR) = 1.6, confidence interval (CI) = 1.2–2.3], though this was not as marked as in other studies. Results indicated that canine leptospirosis in Ontario is a disease of all breeds and ages, regardless of gender. No geographic clustering was noted, but clustering of cases by clinic within geographic areas suggested differences in awareness or in diagnosis by veterinarians. A distinctive seasonal pattern of leptospirosis, with more cases occurring during the summer and fall, as found in previous studies, was also observed in this study. The temporal trend analysis was consistent with an increasing proportion or re-emergence of seroprevalent cases of canine leptospirosis since 1998, suggesting that the putative increase in canine leptospirosis has been genuine.  相似文献   
140.
We investigated the impact of targeted removal of badgers on the subsequent bovine tuberculosis (BTB) risk in cattle herds in county Laois, Ireland. The study period was 1989-2005. For each of 122 targeted badger-removal licenses (permit to remove badgers in the proximity of cattle herds undergoing a serious BTB episode), the herd number (index herd) for which the license was given was obtained. The herds in the proximity of the index herd were identified from another database. The main "exposure" in our study was the geographical location of herds relative to the area in which targeted badger removal was conducted. We categorized herds into five different exposure groups: herds were classified as non-exposed and denoted as group 0 (reference group) if they were located 500 m or more from the edge of any parcel of land of the index herd; group 1, was the index herds, group 2 the immediate (contiguous) neighbors of the index herd, group 3 herds were not immediate neighbors but within 150 m and group 4 herds were between 150 m and 500 m distance from the edge of any parcel of land of the index herd, respectively. We conducted a survival analysis (allowing multiple failures per herd) to compare the hazard of having a BTB episode in any of the four groups of exposed herds vs. the hazard in herds in the reference group. We controlled for other known risk factors as well taking into account a temporal component. Our analysis showed that the hazard ratio for the index herds (group 1) were non-significantly increased, indicating that there was no difference in the hazard of failing a BTB test (after the targeted badger removal was conducted) between index herds and reference herds. For the rest of the herds farther away from badger removal activities the hazards were lower than herds in areas not under badger removal. The hazard in the reference group decreased over the study period.  相似文献   
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