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排序方式: 共有425条查询结果,搜索用时 43 毫秒
41.
Medical records of 81 dogs with severe pulmonic stenosis from 2 referral centers were examined retrospectively. Forty dogs underwent balloon valvuloplasty (BV), which was performed by 1 operator, whereas 41 did not. The mean age at latest follow-up was 41.5 months. A statistical comparison of the clinical outcome and survival was performed. Dogs revealing clinical signs at presentation showed a 16-fold increase in risk of death compared with asymptomatic dogs (P < .001). Statistical analyses demonstrated that an increase of 1 mm Hg in transstenotic pressure gradient (PG) at presentation was associated with a 3% increase in hazard rate (P < .001). Thirty-seven dogs survived BV with a median reduction in PG of 46%. The median preoperative PG was 120 mm Hg, and median PG 24 hours postoperatively was 55 mm Hg with a median of 55 mm Hg 6 months post-BV. Twenty (49%) of the non-BV (NBV) dogs remained asymptomatic at last follow-up. Fourteen (34%) of the NBV dogs died or were euthanized because of heart disease related to pulmonic stenosis. Twelve of these dogs died suddenly, whereas only 1 of the BV dogs died suddenly. After adjusting for PG, clinical signs at presentation, and age, BV or dilation was associated with a 53% reduction in hazard rate (P = .005). This study indicates that BV, when performed by an experienced operator, appears to be successful both in alleviating clinical signs and in prolonging survival in dogs with severe pulmonic stenosis.  相似文献   
42.
REASONS FOR PERFORMING STUDY: Fatalities resulting from horse falls occurring during the cross-country phase of eventing competitions initiated epidemiological investigation of the risk factors associated with horse falls. OBJECTIVES: To identify variables that increased or decreased the risk of a horse fall during the cross-country phase of an eventing competition. METHODS: Data were collected from randomly selected British Eventing competitions held in Great Britain during 2001 and 2002. Data were obtained for 173 cases (jumping efforts resulting in a fall of the horse-and-rider partnership) and 503 matched controls (jumping efforts not resulting in a fall). The risk of falling was modelled using conditional logistic regression. RESULTS: An increased risk of a horse fall was associated with jumping into or out of water; taking off from good-to-soft, soft or heavy ground; fences with a drop landing; nonangled fences with a spread > or =2 m; and angled fences. Other risk factors included riders who knew that they were in the lead within the competition before the cross-country phase; an inappropriate speed of approach to the fence (too fast or too slow); horse-and-rider partnerships that had not incurred refusals at earlier fences; and riders who received cross-country tuition. CONCLUSIONS: This study has identified modifiable course- and fence-level risk factors for horse falls during the cross-country phase of eventing competitions. The risk of horse and rider injury at eventing competitions should be reduced by 3 simple measures; maintaining good to firm take-off surfaces at fences, reducing the base spread of fences to <2 m and reducing the use of fences at which horses are required to jump into or out of water. Risk reduction arising from course and fence modification needs to be confirmed by intervention studies. Potential relevance: Knowledge of factors that increase or decrease the risk of a horse fall can be used by UK governing bodies of the sport to reduce the risk of horse falls on the cross-country phase of eventing competitions, and reduce the risk of horse and rider injuries and fatalities. As one in 3 horses that fall injure themselves and one in 100 horse falls results in fatality to the horse, we suggest that immediate consideration is given to these recommendations.  相似文献   
43.
Background – Canine squamous cell carcinomas (SCCs) most frequently develop on the ventral abdomen and are thought to be caused by ultraviolet (UV) light. Papillomaviruses (PVs) have been associated with cutaneous SCCs in multiple species, including dogs. Hypothesis – That PVs act as cofactors in canine UV‐induced SCCs. Animals – The study was performed on skin from the ventrum of 60 dogs. These samples included 20 SCCs, 20 haemangiosarcomas and 20 samples of clinically normal skin. Two canine viral plaques were included as positive controls for PV. Methods – PCR was used to amplify PV DNA from all samples. Primers used included two sets of consensus primers and two sets of primers that were designed specifically to amplify PV DNA sequences detected in the viral plaques. Results – The MY09/11 consensus primers amplified PV DNA from both viral plaques. One plaque contained a DNA sequence (CfPV‐JM) that had been previously reported from a dog with multiple cutaneous SCCs. The other plaque contained a previously unreported PV DNA sequence. No PV DNA was amplified by either consensus primer from any of the ventrum skin samples. Primers designed specifically to amplify the CfPV‐JM sequence amplified DNA from one SCC, but no other sample. No PV DNA was amplified using the other specific PCR primer set. Conclusions and clinical importance – These results do not support a significant role for PVs in SCC development from the ventrum of dogs. However, they contribute another PV sequence to the list of PVs that have been associated with viral plaque development in dogs.  相似文献   
44.
The Cavalier King Charles Spaniel (CKCS) is prone to severe early onset mitral valve disease. In this study, 36 purebred CKCS dogs were evaluated for mitral valve murmur and divided into early and late onset groups. A genome-wide genetic approach was used to assess whether the condition is determined by a small number of genetic factors. There were no regions of highly discrepant homo/heterozygosity in the two groups. Similarly, there was no evidence for loci associated with mitral valve murmur in a genome-wide association study. This analysis suggests that familial occurrence of mitral valve murmur in the CKCS breed is not due to a single major gene effect, indicating that breeding strategies to eliminate the disease cannot be based on genotype information at this time.  相似文献   
45.
Abstract

CASE HISTORY: A 15-mm diameter mass developed in the S/C tissue overlying the right lateral gluteal muscle of a 6½-year-old female Flat-coated Retriever.

PATHOLOGICAL FINDINGS: Cytological preparations following aspiration of the mass were highly cellular and consisted of a population of large polygonal cells containing single to multiple nuclei, large prominent nucleoli, and intracytoplasmic vacuoles. Histologically, the neoplasm consisted of similar large cells surrounded by thick fibrous connective tissue trabeculae. The large polygonal cells reacted positively with antibodies against vimentin, low- and high-molecular-weight variants of cytokeratin (AE1/AE3), but not with antibodies to desmin or glial fibrillary acidic protein (GFAP).

DIAGNOSIS: The clinical, gross, histological and immunohistochemical findings are similar to those reported for parachordomas in humans. Neither recurrence nor metastases were noted 18 months after surgical excision of the mass.

CLINICAL RELEVANCE: This is the first reported case of a possible parachordoma in a dog, a benign tumour with cytological features of malignancy.  相似文献   
46.
Abstract

AIM: To describe the patterns of use of antimicrobial drugs by veterinary surgeons treating commonly presented bacterial infections in companion animals in New Zealand.

METHODS: A postal survey of 800 randomly selected companion animal veterinarians practicing in New Zealand was conducted between August and December 2008. Data were collected regarding the antimicrobials prescribed for recent cases of skin, ear and urinary tract infections; the use of culture and susceptibility testing; and veterinarian characteristics such as proportion of time spent treating companion animals and recent attendance at continuing professional development (CPD) events. Potential associations within the data were explored using extended mosaic plots and multivariable regression models.

RESULTS:Completed surveys from 393 respondents were available for analysis, providing data on systemic antimicrobial drug use for 1,799 cases of presumptive bacterial infections. The most frequently prescribed drugs were amoxicillin-clavulanic acid (864 cases, 48%), cephalexin (558, 31%), and fluoroquinolones (198, 11%). Of 359 cases of canine superficial pyoderma, 157 (44%) were treated with amoxicillin-clavulanic acid and 155 (43%) were treated with cephalexin with median reported treatment durations of 7 and 10 days, for these two drugs respectively. Culture and susceptibility tests had been used in 376 of 1,984 (19%) of all reported cases and 160 (43%) of these were suspected urinary tract infections. Practitioners that spent 100% of their time treating companion animals and who had attended a CPD course related to companion animals within the 12 months prior to completing the survey were more likely to submit a sample for culture and susceptibility testing and to prescribe longer courses of antimicrobials for the treatment of canine pyoderma than practitioners who spent less than 100% of their time treating companion animals and had not attended a CPD course in the last 12 months.

CONCLUSIONS: Broad-spectrum drugs considered by the World Health Organisation to be critically important for human health, such as fluoroquinolones and amoxicillin-clavulanic acid, are amongst the most frequently prescribed antimicrobials in companion animal medicine, and these drugs are often prescribed without submitting a sample for culture and susceptibility testing.

CLINICAL RELEVANCE: Many cases of superficial pyoderma were treated for less than the recommended duration of 21 days, which may contribute to a higher rate of recurrent pyoderma and the development of drug resistance within the causal bacteria. Veterinarians should be aware that the use of fluoroquinolones, in particular, should be based upon the results of a culture and susceptibility test.  相似文献   
47.
Purpose

Sediment dynamics in most large river basins are influenced by a variety of different natural and anthropogenic pressures, and disentangling these cumulative effects remains a challenge. This study determined the contemporary and historical sources of fine-grained (<?63-μm) sediment in a large, regulated river basin and linked changes in sources to activities in the basin. The river has seen declines in chinook salmon, sockeye salmon, and the endangered Nechako white sturgeon populations, and sediment (both fine-grained and sands) transport and deposition have been identified as potential causes of these declines.

Materials and methods

Samples of suspended sediment and potential source materials were collected from numerous sites distributed throughout the upper Nechako River Basin in British Columbia, Canada. A floodplain sediment core was also collected in order to reconstruct sediment sources over the last ~?70 years. Discriminating fingerprint properties were used within the MixSIAR model to apportion sources among sub-basins and land-use types. Results were compared to records of precipitation and Nechako River discharge trends, and to changes in landscape development.

Results and discussion

Contributions from the erosion of channel banks dominated the suspended sediment load at most sites. Changes in sediment sources during the 2015 field season reflected snowmelt and patterns of water release from the Nechako Reservoir that affected the sediment-carrying capacity of tributaries and the Nechako River main stem. Spatial variations in 2015 also reflected the distribution of land use (e.g., forested or agricultural land) as well as topography (e.g., slope steepness). Over the last ~?70 years, variations in sediment sources and the characteristics of the sediment (e.g., organic matter content and particle size composition) were linked to the construction of the Kenney Dam (operational in 1954) and the impacts of deforestation by the forestry and agricultural industries. Superimposed on these have been wildfires and a major mountain pine beetle infestation leading to higher erosion rates in the affected areas.

Conclusions

The sediment source fingerprinting technique, in combination with historical information on the hydrometeorology and the land use and river management in the basin, has provided valuable information with which to understand sediment dynamics in the Nechako River Basin. Such an approach can help to disentangle how large river systems respond to a combination of natural and anthropogenic pressures.

  相似文献   
48.
ABSTRACT

Aims: To collect baseline data on the contact risk pathways and biosecurity practices of commercial poultry farms in New Zealand, investigate the relationship between the farm-level disease contact risks and biosecurity practices, and identify important poultry health concerns of producers.

Methods: A cross-sectional survey of all registered New Zealand commercial poultry operations was conducted in 2016 collecting information on farm demographics, biosecurity practices, and contact risk pathways. Survey responses were used to generate an unweighted subjective disease risk score based on eight risk criteria and a subjective biosecurity score based on the frequency with which producers reported implementing seven biosecurity measures. Producer opinions towards poultry health issues were also determined.

Results: Responses to the survey response were obtained from 120/414 (29.0%) producers, including 57/157 (36.3%) broiler, 33/169 (19.5%) layer, 24/55 (44%) breeder, and 6/32 (19%) other poultry production types. Median disease risk scores differed between production types (p?<?0.001) and were lowest for breeder enterprises. The greatest risk for layer and broiler enterprises was from the potential movement of employees between sheds, and for breeder enterprises was the on- and off-farm movement of goods and services. Median biosecurity scores also differed between production types (p?<?0.001), and were highest for breeder and broiler enterprises. Across all sectors there was no statistical correlation between biosecurity scores and disease risk scores. Producers showed a high level of concern over effectively managing biosecurity measures.

Conclusions: The uptake of biosecurity measures in the commercial poultry farms surveyed was highly variable, with some having very low scores despite significant potential disease contact risks. This may be related to the low prevalence or absence of many important infectious poultry diseases in New Zealand leading farmers to believe there is a limited need to maintain good biosecurity as well as farmer uncertainty around the efficacy of different biosecurity measures. Further research is needed to understand barriers towards biosecurity adoption including evaluating the cost-effectiveness of biosecurity interventions.  相似文献   
49.
A cross-sectional study was designed to investigate the prevalence and risk factors for Cryptosporidium infection in young calves. Forty-one farms in a discrete, densely farmed 100 km2 area of North West England were visited over a 3-week period and 215 faecal samples were collected from young calves. Farms were not selected on the basis of existing scour problems. At the time of sampling, several investigator-observed variables were recorded at the pen, animal and stool levels. Samples were screened and 60/215 were confirmed as positive by PCR of the 18S rRNA gene. Risk factors for infection were explored using multilevel multivariable logistic regression with farm as a random effect. Age was significant in the final model, with a higher risk of infection in calves aged 8-21 days, when compared to those aged 0-7 days. The depth of the bedding was also significant in the final model, with calves housed in bedding 11-15 cm deep being at lower risk of infection than those on beds 0-5 cm deep. Consistency of the faeces was highly correlated with age and colour of the faeces and was not significantly associated with infection when these variables, and clustering at farm-level, were accounted for. This is interesting as Cryptosporidium is considered to be a primary enteropathogen. The results suggest that intervention strategies should be targeted at calves under 21 days old. These animals represent a significant reservoir of infection on the farm and may also pose a risk to public health, assuming that the species and genotypes shed are zoonotic pathogens.  相似文献   
50.
REASON FOR PERFORMING STUDY: Epiploic foramen entrapment (EFE) is one of the most common causes of small intestinal strangulation in the horse. Identification of risk factors would generate hypotheses about causation and may suggest preventive strategies. HYPOTHESIS: Horses exhibiting certain behavioural patterns and those exposed to particular management practices are at increased risk of EFE. METHODS: A matched case-control study was conducted on EFE cases admitted to hospitals in the UK, Ireland and USA. Data on 109 cases and 310 control horses were obtained by telephone questionnaire and conditional logistic regression was used to identify associations between horse- and management-level variables and the risk of EFE. RESULTS: Crib-biting/windsucking behaviour was strongly associated with increased risk of EFE (OR 67.3, 95%CI 15.3-296.5). A history of colic in the previous 12 months (OR 4.4, 95%CI 1.5-12.7) and horses of greater height (OR/cm 1.05, 95%CI 1.01-1.08) were also at increased risk. The person(s) responsible for horses' daily care (nonowner/relative/spouse OR 5.5, 95%CI 2.3-13.3) and a number of behavioural features, including response to a stimulus causing fright (easily frightened OR 0.4, 95%CI 0.1-1.0) or excitement (sweats up easily/occasionally OR 0.3, 95%CI 0.1-0.8), reaction to their surroundings (inquisitive OR 0.4, 95%CI 0.2-0.8) and feeding behaviour when stressed (goes off food in full/part OR 0.3, 95%CI 0.1-1.0) were also associated with altered risk of EFE. CONCLUSIONS: The association between horses of greater height and those with a previous history of colic and increased risk of EFE suggests that some horses may be inherently predisposed to EFE. Furthermore, a behavioural pattern has been characterised that is common to horses at increased risk of EFE. Further research is required to investigate the causal pathway linking behavioural traits with gastrointestinal dysfunction and to determine whether behavioural modification reduces the risk of EFE. POTENTIAL RELEVANCE: The findings of the present study have relevance to horses in the UK, Ireland and USA.  相似文献   
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