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The infection dynamics of bovine respiratory syncytial virus (BRSV) were studied in randomly selected Norwegian dairy herds. A total of 134 herds were tested twice, six months apart. The herds were classified as positive for BRSV if at least one animal between 150 and 365 days old tested positive for antibodies against BRSV, thereby representing herds that had most likely had the virus present during the previous year. The prevalence of positive herds at the first and second sampling was 34 per cent and at 41 per cent, respectively, but varied greatly between regions. Negative herds were found in close proximity to positive herds. Some of these herds remained negative despite several new infections nearby. Of the herds initially being negative, 42 per cent changed status to positive during the six months. This occurred at the same rate during summer as winter, but a higher rate of animals in the herds was positive if it took place during winter. Of the herds initially being positive, 33 per cent changed to negative. This indicates that an effective strategy to lower the prevalence and the impact of BRSV could be to employ close surveillance and place a high biosecurity focus on the negative herds. [ABSTRACT FROM AUTHOR]

The intention of this collaborative project was eradication of pestivirus from the Norwegian cattle population of about 30,000 dairy and beef herds, primarily by identification and culling of persistently infected (PI) animals. Testing was performed in four tiers, with examination for pestivirus antibodies by indirect ELISA in (1) bulk milk, (2) pooled milk from primiparous dairy cows and (3) pooled blood from young stock. The herds positive in the third tier were examined for pestivirus antigen in blood from all antibody-negative individuals by antigen- capture ELISA, and these animal composed tier (4). Following culling of the PI animals, a herd was considered free from pestivirus when pooled blood from young stock was antibody-negative on two sampling occasions three months apart. Number of herds with PI animals peaked at about 3000 (10 per cent) in the 2nd project year, then decreased steadily; only three herds (0.01 per cent) contained PI animals 10 years later. Solid, continuous information flow to all relevant partners was crucial to project success. The project saved losses of between 50 million and 200 million Norwegian crowns (NOK) annually (approximately 4.5 million to 18 million GBP). Project running costs for 10 years were 52.4 million NOK. Following project completion, surveillance of the Norwegian cattle population for pestivirus has continued. [ABSTRACT FROM AUTHOR]

The article presents a study which describes the pathological findings from the intestinal adenocarcinomas in three generations of sheep in Norway. Postmortem examination of the ewes conducted at the Norwegian School of Veterinary Science is highlighted. The study concludes that a genetic predisposition is present in the three closely related sheep.

The use of injectable transponders in cattle for identification purposes, for up to 30 months, was investigated. Passive electronic transponders, encapsulated in either polymer or glass, were injected subcutaneously into either the ear base or the earlobe of 652 calves in three populations. The animals were clinically examined weekly, and transponder signalling was checked immediately before and after injection, after two weeks and after about eight months. About 10 per cent of animals in one population were also checked after 20 and 30 months. No severe clinical or visible pathological changes were observed, and the calves' welfare was not apparently affected by the procedure. None of the transponders migrated from their injection sites. Eight months after injection, a signal was detected from 98.2 per cent of transponders injected in the ear base and from 90.5 per cent of those in the earlobe. At 20 and 30 months after injection, 10.4 per cent and 2.6 per cent of transponders, respectively, had ceased to signal. Thus, most transponders in the calves' ear base demonstrated functionality for up to 30 months. [ABSTRACT FROM AUTHOR]

Based on the widespread use of homeopathy in treatment of animal disease and the poor documentation of its possible effects and consequences, a clinical trial was carried out in order to evaluate the efficacy of homeopathy in treatment of clinical mastitis in dairy cows and a design for clinical studies on homeopathic treatment, taking into account the guidelines for randomized-clinical trials (RCT) as well as the basic principles of homeopathy. A three-armed, stratified, semi-crossover design comparing homeopathy, placebo and a standardized antibiotic treatment was used. Fifty-seven dairy cows were included. Evaluation was made by two score scales, with score I measuring acute symptoms and score II measuring chronic symptoms, and by recording the frequencies of responders to treatment based on four different responder definitions. Significant reductions in mastitis signs were observed in all treatment groups. Homeopathic treatment was not statistically different from either placebo or antibiotic treatment at day 7 (P = 0.56,P = 0.09) or at day 28 (P = 0.07,P = 0.35). The antibiotic treatment was significantly better than placebo measured by the reduction in score I (P < 0.01). Two-thirds of the cases both in the homeopathy and placebo groups responded clinically within 7 days. The outcome measured by frequencies of responders at day 28 was poor in all treatment groups. Evidence of efficacy of homeopathic treatment beyond placebo was not found in this study, but the design can be useful in subsequent larger trials on individualized homeopathic treatment. [ABSTRACT FROM AUTHOR]

There is often a need to reduce sample size in clinical trials due to practical limitations and ethical considerations. Better comparability between treatment groups by use of stratification in the design, and use of continuous outcome variables in the evaluation of treatment results, are two methods that can be used in order to achieve this. In this paper the choice of stratification factors in trials of clinical mastitis in dairy cows is investigated, and two score-scales for evaluation of clinical mastitis are introduced. The outcome in 57 dairy cows suffering from clinical mastitis and included in a clinical trial comparing homeopathic treatment, placebo and a standard antibiotic treatment is investigated. The strata of various stratification factors are compared across treatments to determine which other factors influence outcome. The two score scales, measuring acute and chronic mastitis symptoms, respectively, are evaluated on their ability to differentiate between patients classified from clinical criteria as responders or non-responders to treatment. Differences were found between the strata of the factors severity of mastitis, lactation number, previous mastitis this lactation and bacteriological findings. These factors influence outcome of treatment and appear relevant as stratification factors in mastitis trials. Both score scales differentiated between responders and non-responders to treatment and were found useful for evaluation of mastitis and mastitis treatment. [ABSTRACT FROM AUTHOR]

Summary Twenty-two heifers were infected intranasally with non-cytopathic bovine viral diarrhoea virus (BVDV) between days 74 and 82 of pregnancy. All animals had developed serum antibodies against BVDV 5 weeks later. No clinical effects were seen in the heifers, and they all delivered a live calf. The newborn calves were generally small, appeared unthrifty as typical ‘poor doers’, and some developed secondary infections with diarrhoea and signs of respiratory disease. Eighteen of the 22 calves were born without antibodies against BVDV and were persistently infected (PI) with the virus. One was weak at birth and died the following day. Four calves were born with serum antibodies against BVDV and with no detectable virus. Three of these showed signs and/or pathological changes indicating disease in the central nervous system. Otherwise, there were no obvious clinical differences between these calves and the PI calves, nor were there any apparent significant differences in blood parameters between these groups. In general, the calves showed low γ -globulin values and thrombocytopaenia, but moderately increased fibrinogen values and relatively normal lymphocyte numbers. [ABSTRACT FROM AUTHOR]

Neutralising serum antibodies against bovine virus diarrhoea virus (BVDV) were monitored for three years in 35 cattle that were infected with the virus as calves; 24 of the calves were inoculated intramuscularly or intranasally, and 11 contracted the infection naturally. All the experimentally infected calves seroconverted within 14 to 28 days after inoculation, and all the animals still had high serum levels of antibodies to BvDv three years after infection. Determinations of antibody levels in milk and blood samples excluded the possibility that the calves had been reinfected with BvDv during the study. [ABSTRACT FROM PUBLISHER]

Blood samples from 24 calves undergoing experimental acute infection with a noncytopathogenic bovine viral diarrhoea virus (BVDV) were examined for viral antigen in peripheral leucocytes with an enzyme-linked immunosorbent assay (ELISA), and for presence of virus in blood plasma in a cell culture assay. With the antigen ELISA, low positive values were detected in leucocytes sampled on days 3-4 from two of eight animals inoculated intranasally, and on days 11-13 from three of 16 animals inoculated intramuscularly. From 22 of the animals, low titres of BVDV were detected in blood plasma obtained 2-9 days after inoc***ulation. All other samples, drawn between 2 and 21 days after inoculation, were negative for viral antigen. All animals seroconverted 3-4 weeks after inoculation, some after having shown mild and transient signs of disease. [ABSTRACT FROM AUTHOR]

This paper describes the first cases of malignant catarrhal fever (MCF) in pigs in which the diagnosis was verified aetiologically by polymerase chain reaction (PCR) and DNA analysis and by the demonstration of antibodies. Three pigs on two separate premises showed clinical signs, gross pathological and histopathological lesions which were in many respects similar to those of MCF in ruminants. The pigs were housed adjacent to sheep and DNA of ovine herpesvirus-2 (OHV-2) was detected by PCR in tissues of all the pigs. In addition, antibody to alcelaphine herpesvirus-1 was detected in the serum of the pigs and in five in-contact sheep. It is concluded that the disease described is MCF of pigs caused by OHV-2. [ABSTRACT FROM PUBLISHER]