摘要:

To reproduce experimentally clinical bovine respiratory syncytial virus (BRSV) infections in cattle, we isolated BRSV from a calf in the field that suffered from acute respiratory disease. Cell culture passage of the virus was avoided to prevent any modification of the biological properties of the virus. The isolated BRSV was passaged in specific‐pathogen‐free (SPF) calves. Lung lavage fluids of these calves, which contained at least 103TCID50/ml BRSV and which were found to be free of other known respiratory pathogens, were collected and pooled for experimental infection. To reproduce a clinical BRSV infection, two groups of six SPF calves were inoculated intranasally with 2 ml of 103.9TCID50/ml BRSV of the obtained virus stock. Another five calves, which were persistently infected with bovine virus diarrhoea virus (BVDV), were given the same inoculum. One group of six calves served as mock‐infected controls. Clinical signs were closely monitored from 1 week before until 16 days after inoculation. Reproducible clinical signs consisting of significantly (p<0.05) increased respiratory rates and elevated body temperatures were recorded but not in all BRSV‐inoculated calves. Although clinical signs were induced by experimental infection with non‐cell‐culture‐passaged BRSV, the respiratory signs were not as serious as in the most severe cases in the field.

ISSN:0165-2176    

DOI:10.1080/01652176.1996.9694622

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Morbidity due toCorynebacterium pseudotuberculosisinfection occurred in 29 dairy herds. The disease appeared basically in three clinical forms: cutaneous, mastitic, and visceral. The appearance of the disease showed a marked seasonality: in 23 herds it occurred during the spring and summer months (dry season) (March‐October). The mastitic form occurred in only 10 herds and the causative bacterium was isolated from 33 cows (5.8%). All the strains of C.pseudotuberculosisisolated from the milk samples were found not to be nitrate reducers. The bacterium was excreted in the milk of six cows from herd B during a period of 11 months. In the mastitic cows, a decrease in milk production and considerable increases in the somatic cell count were noted.

ISSN:0165-2176    

DOI:10.1080/01652176.1996.9694623

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Conditions (total complex of stressors) during the transport of animals vary strongly between and within transports. Adverse climatic conditions are stressors that animals have to face during transport. The thermoregulation of animals is discussed with respect to threshold values for optimal climatic conditions. These thermal thresholds depend on animal related factors and environmental conditions. The specific impact of transport conditions, such as food and water deprivation, high stocking density, high humidity and high air velocity, on thermal thresholds are described.

ISSN:0165-2176    

DOI:10.1080/01652176.1996.9694624

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Sero‐epidemiological surveys have revealed that equine arteritis virus (EAV) is prevalent in most European countries. The virus causes sporadic cases of respiratory disease and abortion in horses, the incidence of which has increased in recent years. Mares and geldings eliminate virus after acute infection, but 30% to 60% of stallions become persistently infected. In these animals, EAV is maintained within the reproductive tract and is shed continuously in the semen. Persistent infection with EAV in stallions has no negative consequences for fertility but mares inseminated with virus‐contaminated semen can have an acute infection. These mares shed large amounts of virus in respiratory secretions and urine, leading to lateral spread of the virus to other susceptible horses. Acute infection at later stages of gestation can lead to abortion. Effective control of the spread of EAV infection depends on the identification of virus‐shedding stallions. Persistently infected stallions should not be used for breeding or should be bred only to seropositive mares. Mares bred to shedding stallions should be isolated from other animals for a period of 3 weeks following insemination to prevent the lateral spread of EAV.

ISSN:0165-2176    

DOI:10.1080/01652176.1996.9694625

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Risk indicators forPasteurella haemolyticarelated summer pneumonia in lambs in the Netherlands were investigated using a mail questionnaire survey of 860 flocks. The response rate was 64% (n=550). Multivariate risk analysis indicated that taking sheep to sheep fairs, the purchase of sheep and/or lambs, the lack of possibility for indoor housing, and an increased flock size were associated with increased risk of occurrence of summer pneumonia in lambs of the home flock.

ISSN:0165-2176    

DOI:10.1080/01652176.1996.9694626

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Three cats presented with painful, putrid smelling ulcers on their thighs and around their tails. Examination of the fly larvae found in the ulcers revealed that the cats suffered cutaneous blowfly myiasis caused byCalliphora erythrocephalalarvae. Obesity was one of the predisposing factors for the development of this parasitic condition. After therapy with ivermectin, the larvae disappeared within two days.

ISSN:0165-2176    

DOI:10.1080/01652176.1996.9694627

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

This article reviews current knowledge concerning enzootic pneumonia. Enzootic pneumonia, caused byMycoplasma hyopneumoniaeand exacerbated by secondary invaders, occurs worldwide and has been known for many years. The organism, with its typical characteristics, invades the respiratory tract in several successive steps. Clinical symptoms and lesion development are the result of the pathogenic capacity ofMycoplasma hyopneumoniaeand the defence reactions in the lung. The economic relevance of pneumonia is influenced to a large extent by common secondary infections which follow an initialM. hyopneumoniaeinfection. Different tests for the diagnosis of pneumonia in individual pigs and in groups are available. Treatment and control is not simple since enzootic pneumonia is a multi‐factorial disease. Some epidemiological aspects and the most important measures for prevention of the disease are described.

ISSN:0165-2176    

DOI:10.1080/01652176.1996.9694628

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

The prevalence of tapeworm infestations was investigated in 70 horses slaughtered in the period February 1994 ‐ July 1994. Most horses were half‐breed, young (1.5 ‐ 3 years), and in good condition. They were bought for slaughter by dealers on local markets, and their treatment history was therefore unknown.

ISSN:0165-2176    

DOI:10.1080/01652176.1996.9694629

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Cytological examination of biopsy samples obtained by fine‐needle aspiration appears to be an accurate and reliable basis for the classification of canine non‐Hodgkin's lymphoma (NHL). Intra‐ and inter‐observer reproducibility of both the original and the updated Kiel classification were assessed blindly on two occasions by two experienced cytologists who examined biopsy specimens from 78 dogs with NHL. Analysis by kappa statistics showed moderate to good intra‐observer reproducibility and poor to moderate inter‐observer reproducibility for the original Kiel classification. In the updated Kiel classification both intra‐ and inter‐observer reproducibilities were good, probably due in part to the additional information provided by the immunotyping. The consensus cytological classifications were compared with those based on histology, and the association constant (Cramér's V) was 0.65 for the original Kiel classification and 0.70 for the updated Kiel classification. The results suggest that the updated Kiel classification in particular is suited to cytological classification of canine NHL.

ISSN:0165-2176    

DOI:10.1080/01652176.1996.9694630

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0165-2176    

DOI:10.1080/01652176.1996.9694631

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor