Vitamin D deficiency syndromes in swine(Ⅰ)

维生素D是一种脂溶性维生素,由皮肤产生或日粮供应.在被吸收进入血液后,维生素D在肝脏内转化成25-羟基维生素D(25(OH)D)),这是维生素D在血液中最主要的存在形式.25(OH)D)在肾脏中被进一步分解成1,25-二羟基维生素D(1,25-(OH)2D).     

A common neutralizing epitope on envelope glycoprotein E2 of different pestiviruses: implications for improvement of vaccines and diagnostics for classical swine fever (CSF)?

The Pestivirus genus within the family of Flaviviridae consists of at least three species; classical swine fever virus (CSFV) found in swine and wild boar, bovine viral diarrhoea virus type 1 and type 2 (BVDV-I and BVDV-II) mainly isolated from cattle and border disease virus (BDV) preferably replicating in ovine species. Many features demonstrate differences between CSFV and other pestiviruses, BVDV-I, BVDV-II and BDV, here defined as nonCSFV, whereas other features show similarities between all different species of pestiviruses. Focussing on the major envelope glycoprotein E2, the immunodominant protein of pestiviruses, CSFV seems to be a more distinct species within the Pestivirus genus. Here we confirm on one hand the more separated grouping of CSFV by isolation of monoclonal antibodies (MAbs) raised against E2 of BVDV-I and BVDV-II. None of these MAbs recognize E2 of CSFV strains. On the other hand, only one MAb, MAb 912, was isolated against E2 of BDV. MAb 912 binds to E2 of CSFV strains and partly neutralizes CSFV. The epitope of MAb 912 is mapped in antigenic domain B of CSFV-E2. This common epitope of CSFV strains and nonCSFV strains could have implications for development of DIVA vaccines and serological diagnostics for CSF.     

Equine exudative canker: an (auto-)immune disease?

Equine canker is a chronic, hyperplastic, exudative pododermatitis affecting one or more feet. Although many causes and treatments have been suggested, the cause of the disease is still unknown and most probably multifactorial. Local treatments include radical surgical debridement of the diseased hoof tissue and application of caustic substances, antibiotics, and pressure bandaging. Nevertheless, the number of recurrences is high (45%). This article presents a 3-year-old New Forest pony-cross mare in which all horny structures (frogs, coronets, spurs, chestnuts) of all feet were affected. Bacteriological and fungal cultures of the frogs were found negative for the pathogens tested. Papilloma virus was not found. Clinical findings raised the hypothesis that the non-specific hyperplastic inflammation of these horn-like structures might have been caused by an (auto-)immune reaction. On the basis of the clinical findings, the pony was treated with surgical debridement of the frogs of a diagonal pair of feet and oral administration of prednisolone (1 mg/kg sid). The frogs, coronets, spurs, and chestnuts of all four feet healed completely within 8 weeks, thus making an (auto-)immune reaction more likely. In conclusion, this case report raised the hypothesis that an aspecific, hyperplastic inflammation of all four feet ('equine canker') and other horny structures may be caused by an (auto-)immune reaction, and that corticosteroids (prednisolone 1 mg/kg sid per os) are effective as treatment.     

Insights into host-microbe interaction:What can we do for the swine industry?

Recent discoveries have underscored the cross-talk between intestinal microbes and their hosts. Notably, intestinal microbiota impacts the development, physiological function and social behavior of hosts. This influence usually revolves around the microbiota-gut-brain axis (MGBA). In this review, we firstly outline the impacts of the host on colonization of intestinal microorganisms, and then highlight the influence of intestinal microbiota on hosts focusing on short-chain fatty acid (SCFA) and tryptophan metabolite-mediated MGBA. We also discuss the intervention of intestinal microbial metabolism by dietary supplements, which may provide new strategies for improving the welfare and production of pigs. Overall, we summarize a state-of-the-art theory that gut microbiome affects brain functions via metabolites from dietary macronutrients.     

Efficacy of vaccines against bacterial diseases in swine: what can we expect?

This paper discusses what can be expected with regard to efficacy of antibacterial vaccines used in swine, based on the present knowledge of pathogen–host interactions. First, vaccination against bacteria that mainly cause disease by production of exotoxins is considered. Vaccines containing the inactivated toxin or a non-toxic but antigenic recombinant protein derived from the exotoxin can be expected to provide protection against disease. The degree of protection induced by such vaccines varies, however, depending amongst other things on the pathogenesis of the disease. Vaccination against clostridial infections, Actinobacillus pleuropneumoniae infections, progressive atrophic rhinitis and enterotoxigenic Escherichia coli, is considered. The second part of the article deals with vaccination against extracellular bacteria. Protection against these bacteria is generally mediated by antibodies against their surface antigens and certain secreted antigens, but cellular immunity may also play a role. Efficacy of vaccines against swine erysipelas, Streptococcus suis infections, Mycoplasma hyopneumoniae infections and swine dysentery is discussed. Finally, vaccination against facultatively intracellular bacteria is considered. For protection against these bacteria cell-mediated immunity plays an important role, but antibodies may also be involved. It is generally accepted that live-attenuated vaccines are more suitable for induction of cell-mediated immunity than inactivated vaccines, although this also depends on the adjuvant used in the vaccine. As an example, vaccination against Salmonella enterica serotype Typhimurium is discussed.     

Larval cyathostominosis in horses in Ontario: an emerging disease?

From 1991 to 2003, 24 cases of larval cyathostominosis were diagnosed at postmortem in equids, 15 (63%) from 2001 to 2003. Cases occurred from September to May, the majority from October to December. Median age was 12 mo. Diarrhea, colic, and weight loss were common clinical signs. Hypoalbuminemia and microcytosis were consistent findings.     

Canine leishmaniosis in the United Kingdom: A zoonotic disease waiting for a vector?

Leishmaniosis is an important sand fly transmitted protozoan disease of dogs and humans. In northern Europe, infection is mainly restricted to dogs that have travelled to and/or from endemic areas of the Mediterranean region during periods when there is high sand fly exposure, mostly between March and November. Infected dogs in these areas in northern latitudes are a potential reservoir should incursion of a competent vector occur. However, information on the scale of the potential reservoir in the UK is lacking. Confirmed cases of canine leishmaniosis entering the United Kingdom between 2005 and 2007 were identified using diagnostic samples submitted to the Department of Clinical Veterinary Science, University of Bristol and from collaborating laboratories (n = 257). All study dogs had clinico-pathological signs compatible with leishmaniosis, as typically reported in endemic countries and were leishmania positive in real time or conventional PCR tests, IFA serology and/or tissue microscopic examination for amastigote identification. Information obtained from each case included travel history, habitat, clinico-pathological findings and geographical location once located in the UK. The majority of dogs with complete travel history (n = 183) had spent at least 6 months in Spain (105/183), 28/183 were rescued from re-homing centres in the country of origin and 26/183 entered the UK with confirmed leishmaniosis. Once located in the UK, the majority of positive cases were resident in south and central England. The spectrum of clinico-pathological signs for this group of dogs is similar to that reported in endemic countries. These data confirm that a potentially significant reservoir of infected dogs is resident in areas where future climatic conditions may support introduction of competent vectors.     

Polychondritis: a new disease in Swiss Braunvieh?

Over the last 10 years Swiss Braunvieh cattle with malformations of the pinnae have repeatedly been reported. Endoscopy revealed a shortened and thickened epiglottis and malformations of the arytenoid cartilage in some of these animals. In most cases the elastic cartilage was replaced by fibrocartilage and hyaline cartilage. The direct cause and pathogenesis of the malformations could not be determined.     

Comparison of disease trends in the Ontario swine population using active practitioner-based surveillance and passive laboratory-based surveillance (2007–2009)

A concern about emerging swine diseases led to a pilot study to determine the feasibility of an active surveillance system referred to as the Ontario Swine Veterinary-based Surveillance System (OSVS). The OSVS recorded the incidence of various syndromes and investigated potential outbreaks. However, validation of the disease patterns observed was needed. The objective of this study was to compare the disease patterns observed in the OSVS system with submission data obtained from a regional diagnostic laboratory — the Animal Health Laboratory (AHL). Higher rates of submission were reported to the OSVS compared with AHL records. However, OSVS and AHL data captured similar trends of disease. The OSVS data captured potential outbreaks that were not reflected in the laboratory data. Validation of active and passive syndromic surveillance data is necessary, and efforts should be made to integrate these types of data sources.     

Bacterial killing activity and lysozymes: A stable defence mechanism in stallion seminal plasma?

During insemination, bacterial contamination of the ejaculate can lead to reduced sperm quality and transmission of pathogens to the female, thus should be avoided. The semen of a variety of animal taxa possess antimicrobial properties against a wide range of bacterial species through antimicrobial molecules, such as lysozyme, but their variance and the factors influencing it are unknown for most species. In this study, the antibacterial defence (bacterial killing activity (BKA) against Escherichia (E.) coli and Staphylococcus (S.) aureus as well as lysozyme concentration) was studied in seminal fluid from two consecutive ejaculates of 18 stallions. All ejaculates showed BKA against the tested bacteria, which correlated between the two consecutive ejaculates (r_S = 0.526, p = .025 for E. coli and r_S = 0.656, p = .003 for S. aureus) and appeared to be stable over the tested period. The lysozyme concentration (LC) showed no significant correlation between the consecutive ejaculates (r_S = 0.161, p = .681). However, LC had a positive correlation to the ratio of apoptotic spermatozoa within the ejaculates (r_S = 0.426, p = .019). In contrast to other livestock (e.g., boar, bull), the BKA in stallion semen did not correlate significantly with the age of the animal nor sperm quality characteristics.     

Undifferentiated bovine respiratory disease (shipping fever): Is it communicable?

A study was conducted on 6–8-month old calves entering 2-research facility feedlots in 1983–1985, to examine if the occurrence of undifferentiated bovine respiratory disease (BRD) clustered within pens. For the purposes of analysis, 12 different groups of cattle were formed based on the source of cattle within year and/or year of arrival.The morbidity rates of BRD ranged from 5.7 to 64% and varied significantly from group to group (i.e., source to source) within year and from year to year. In all groups except one, the secondary attack (morbidity) rates were lower than the morbidity rates.An algorithm to examine for extra-binomial variation was used to formally examine for pen effects (clustering of disease within pen). In all models, a simple binomial model was sufficient to describe the data, i.e., the usual binomial parameter was estimated to describe the mean level of BRD by group, no additional parameter estimates were required to describe pen effects within group.Thus, although BRD has important pathogens as part of its sufficient causes, there is no evidence that clinical disease in one individual increases the risk of disease for other cattle in the same pen.     

Canine brain tumours: a model for the human disease?

Canine brain tumours are becoming established as naturally occurring models of disease to advance diagnostic and therapeutic understanding successfully. The size and structure of the dog's brain, histopathology and molecular characteristics of canine brain tumours, as well as the presence of an intact immune system, all support the potential success of this model. The limited success of current therapeutic regimens such as surgery and radiation for dogs with intracranial tumours means that there can be tremendous mutual benefit from collaboration with our human counterparts resulting in the development of new treatments. The similarities and differences between the canine and human diseases are described in this article, emphasizing both the importance and limitations of canines in brain tumour research. Recent clinical veterinary therapeutic trials are also described to demonstrate the areas of research in which canines have already been utilized and to highlight the important potential benefits of translational research to companion dogs.     

Myxomatous mitral valve disease in dogs: Does size matter?

Myxomatous mitral valve disease (MMVD) is the most commonly diagnosed cardiovascular disease in the dog accounting for more than 70% of all cardiovascular disease in dogs. As are most canine diseases with genetic underpinnings, risk of MMVD is greatly increased in a subset of breeds. What is uncommon is that the vast majority of the breeds at elevated risk for MMVD are small or toy breeds with average adult weights under 9 kg. These breeds appear to have little in common other than their diminutive size. In the following review we propose a number of mechanisms by which relatively unrelated small breeds may have developed a predisposition for chronic valvular disorders. Although factors such as age are key in the expression of MMVD, taking a comprehensive look at the commonalities, as well as the differences, between the susceptible breeds may assist in finding the causal variants responsible for MMVD and translating them to improved treatments for both dogs and humans.