Emergence and recent evolution of canine parvovirus.

This review summarizes the current knowledge about the emergence of canine parvovirus from an ancestor virus similar to feline panleukopenia virus most likely from a wild carnivore host. The recent evolution of CPV, namely the emergence of new antigenic types, their biological properties and global distribution are also discussed.     

M gene evolution of canine coronavirus in naturally infected dogs

Two stray pups (A and B), three and five months old, respectively, both naturally infected with canine coronavirus (CCoV), were studied for 180 days. The virus was detected intermittently in the pups' faeces by PCR for periods of 156 and 146 days, respectively. Sequence analysis of a fragment of the gene encoding the M protein revealed that the viruses detected at the onset of the infection were very similar to typical strains of CCoV, whereas from 42 days after infection in pup A and 40 days after infection in pup B the viruses had nucleotide and amino acid mutations resembling sequences in feline coronavirus.     

Genetic distance of SARS coronavirus from the recent natural case

Phylogenetic analysis of SARS coronavirus isolates based on the spike gene and protein sequence using Neighbor-Joining, maximum likelihood and Bayesian inference methods indicated that a recent human SARS-CoV isolate was closer to some human SARS-CoV isolates from earlier epidemic phase than to the SARS-CoV-like viruses isolated from wild animals during previous epidemic phase. A reasonable judgment based on phylogenetic relationship and sequence variations it is likely that the recent human SARS-CoV isolate is closer to an unknown SARS-CoV predecessor.     

Genetic diversity of avian infectious bronchitis coronavirus in recent years in China

Fifty-six isolates of avian infectious bronchitis virus (IBV) were obtained from different field outbreaks in China in 2010, and they were genotyped by comparison with 19 reference strains in the present study. The results showed that LX4-type isolates are still the predominant IBVs circulating in chicken flocks in China, and these isolates could be grouped further into two clusters. Viruses in each cluster had favored amino acid residues at different positions in the S1 subunit of the spike protein. In addition, a recombination event was observed to have occurred between LX4- and tl/CH/LDT3/03I-type strains, which contributed to the emergence of a new strain. The most important finding of the study is the isolation and identification of Taiwan II-type (TW II-type) strains of IBV in mainland China in recent years. The genome of TW II-type IBV strains isolated in mainland China has experienced mutations and deletions, as demonstrated by comparison of the entire genome sequence with those of IBV strains isolated in Taiwan. Pathogenicity testing and sequence analysis of the 3' terminal untranslated region revealed that TW II-type IBV strains isolated in mainland China have a close relationship with the embryo-passaged, attenuated TW2296/95.     

Serological prevalence of canine respiratory coronavirus in southern Italy and epidemiological relationship with canine enteric coronavirus.

Canine respiratory coronavirus (CRCoV) has been detected in dogs suffering from respiratory disease and is thought to be involved in canine infectious respiratory disease (CIRD) complex. Canine enteric coronavirus (CECoV) is a widespread pathogen of dogs, responsible for mild to severe diarrhea in pups. The purpose of this study was to establish the seroprevalence of CRCoV in Italy and its relationship to CECoV type II seroprevalence. The age and year of sample collection from seropositive dogs was also assessed. Of adult domestic dogs, 23.3% had antibodies to CRCoV, compared with 86.1% with antibodies to CECoV. Amongst a population of kenneled pups, 4.0% had antibodies to CRCoV, and 97.0% had antibodies to CECoV.     

Antimicrobial prophylaxis in canine surgery

In 1961, Burke showed that antibiotics affect primary wound infections favourably only if they are administered before or shortly after bacterial contamination. The effect is optimal if there is already an effective tissue concentration at the time of contamination. During surgery the animal's resistance is strongly reduced, and consequently an infection may be caused by an inoculum present in a rather low concentration, at least lower than in normal circumstances. This reduced resistance lasts until only a few hours after operation. Prophylactic use of antibiotics therefore needs to be continued only for a short time after the final stage of the operation. A great number of clinical trials in human surgery have shown that short term peri-operative prophylactic use of antibiotics causes a reduction in the incidence of post-operative septic complications, in certain categories of operations and in selected groups of patients. Until properly designed, prospective, randomized and controlled clinical trials have been done in small animal clinics, it seems sensible to apply the abundant results from research with experimental animals and from clinical trials in human medicine to small animal surgery. Prophylactic use of antibiotics is indicated if the infection risks or dangers of possible complications are greater than the disadvantages of regular use of antibiotics. The risk factors in the development of wound infections and the choice of antibiotics are discussed.     

Serological prevalence of canine respiratory coronavirus

Canine respiratory coronavirus (CRCoV) has recently been detected in dogs; it is a group 2 coronavirus showing similarity to bovine coronavirus (BCoV) but is distinct from canine enteric coronavirus (CECoV). CRCoV may play an important role in canine infectious respiratory disease (CIRD) either by predisposing to further and potentially more serious viral and bacterial infections or possibly as a primary pathogen. The prevalence of serum antibodies to CRCoV, in a population of dogs in the south east of England, has been shown previously to be 30.1% on the first day of entry to a rehoming kennel [Erles, K., Toomey, C., Brooks, H.W., Brownlie, J., 2003. Detection of a group 2 coronavirus in dogs with canine infectious respiratory disease. Virology 310, 216-223]. The purpose of this study was to establish the prevalence of CRCoV in the general canine population within as well as outside the UK. An ELISA, used to test for the presence of antibodies to CRCoV in canine serum samples, identified seropositive dogs in UK, USA, Canada, Republic of Ireland and Greece. The development of an ELISA based on CRCoV antigen and immunofluorescence assay are described here. 54.7% (547/1000) of North American and 36.0% (297/824) of United Kingdom dogs were seropositive for CRCoV. The age and geographical distribution of seropositive dogs was also assessed. The cross-reactivity demonstrated between CRCoV antibodies from different countries and a UK viral isolate suggests immunological similarity. The overall prevalence of this virus in both North America and the UK suggests that CRCoV has international significance and that further epidemiological studies are required.     

浅谈犬瘟热的综合防制

犬瘟热是由副粘病毒属的犬瘟热病毒引起的一种高度接触性传染病 ,以高烧 (双峰热 )、侵害粘膜为主要特征。1　流行病学犬瘟热是犬的固有传染病 ,尤其对幼犬的危害最严重。犬瘟热易患动物不仅有犬 ,还包括犬科动物、猫科动物、鼬科动物。据报道海豹也发此病。所以此病有广泛的传染源存在。此病主要通过飞沫传播。在早期发热阶段 ,眼、鼻的浆性分泌物中含有大量病毒 ,病犬的粪尿也含有病毒 ,可通过污染物体传播本病。狗舍、运动场地、饲养用具和犬经常聚集的其他场所均有病毒驻留。2　临床症状和病理变化病犬初期食欲减退 ,眼、鼻流水样分泌物…     

辽宁省警犬犬瘟热犬细小病毒和犬冠状病毒感染情况调查

犬传染病是危害养犬业健康发展的主要疾病,来自警犬方面的统计资料证实,全国每年免疫警犬的发病率为14％,其中传染病占60％以上,因传染病而死亡的犬超过死亡犬总数的80％。从近几年的临床实践和国外的有关报道来看,危害严重的犬病毒病主要有犬瘟热、犬细小病毒感染、犬传染性肝炎、犬冠状病毒病、犬副流感及狂犬病等6种疾病,     

瘦蛋白及其在养猪业上的研究进展

瘦蛋白 (Leptin)是脂肪细胞分泌的一种调节体脂沉积的重要因子 ,由 1 67个氨基酸残基组成 ,其中N端 2 1个氨基酸残基为信号肽 ,成熟瘦蛋白为 1 46个氨基酸残基组成的无糖化的多肽 ,相对分子量为 1 6kDa ,其中mRNA长 4 5kb。Leptin为单链 ,链内的两个半胱氨酸构成一个二硫键 ,这种结构也常见于其他分泌型多肽。就氨基酸序列分析 ,Leptin是一种球型分子 ,无明显的结构域或跨膜区 ,以单体形式存在 ,是由肥胖基因 (Obesegene ,简称ob基因 )编码的 ,其表达具有组织特异性 (Dennis等 ,1 997) ,表达部位主要在脂肪组织。Leptin作用于下丘脑的…     

The seroprevalence of canine respiratory coronavirus and canine influenza virus in dogs in New Zealand

Abstract

AIM: To determine whether canine respiratory coronavirus (CRCoV) and canine influenza virus (CIV) are present in dogs in New Zealand.

METHODS: Serum samples from 251 dogs of varying age, breed and clinical histories were tested for the presence of antibodies to CRCoV and CIV, using indirect fluorescent antibody (IFA) analysis. The population sampled represented a wide geographic area but principally encompassed the central and lower North Island of New Zealand.

RESULTS: Seventy-three of the 251 samples (29%) were seropositive for CRCoV. Dogs <2 years old were less likely to be seropositive for CRCoV than older dogs. None was seropositive for CIV.

CONCLUSIONS: This study revealed the presence of antibodies to CRCoV in dogs in New Zealand. Young dogs are less likely to be seropositive than older dogs, probably due to increased opportunity for exposure to CRCoV over time. Serum antibodies to CIV were not detected in any of the dogs sampled, suggesting that this virus is unlikely to be present in dogs in New Zealand.

CLINICAL RELEVENCE: Canine respiratory coronavirus is present in New Zealand. Although the role of this virus in canine infectious tracheobronchitis has not been fully elucidated, evidence suggests that it may have a causal role in this disease. Veterinarians should consider CRCoV as a differential diagnosis in cases of respiratory disease in dogs in New Zealand. While CIV appears not to be currently present in New Zealand, veterinarians should consider infection with this virus as a differential diagnosis in dogs presenting with respiratory signs.     

犬冠状病毒病的实验室诊断

犬冠状病毒病是由犬冠状病毒 (canine coro-navirus,CCV)引起犬急性胃肠炎的一种高度接触性传染病 ,临床上表现为剧烈的呕吐、腹泻 ,症状消失后 2～ 3周 ,还可能复发 ,是当前对养犬业危害较大的疫病之一 [1] 。由于犬冠状病毒的流行病学特点、临床症状和病理剖检均缺乏特征性变化 ,在血液学和生物化学方面也没有特定指标 ,故对于该病的确诊往往必须通过实验室诊断。近年来 ,国内外在犬冠状病毒病诊断方面的研究十分活跃 ,尤其是在分子病毒学诊断方面取得了可喜进展 ,现就这些方法综述如下。1　电子显微镜和免疫电镜观察取粪便悬液作负染后…     

Recent advances in canine virus research

The widespread application of techniques such as electron microscopy and immunofluorescence in the study of canine viruses has significantly advanced our knowledge particularly with regard to CAV–ICH and CDV. The isolation of new viruses particularly from the respiratory tract has stimulated renewed interest in upper respiratory disease in the dog. The fact that a single virus may cause a number of diseases with, for example, CAV–ICH being associated with respiratory, liver and renal disease while some infections, e.g. upper respiratory disease, can be associated with a number of viruses emphasizes the complexity of canine virus infections. Although many aspects of the pathogenesis of canine virus infections have been carefully studied, it is hoped that more attention will be directed to many of the unanswered questions concerning the role of immunological factors. Résumé. Résumé. L'application universelle de techniques telles que la microscopie électronique et l'immunonuorescence dans l'tude des virus canins a accru nos connaissances de façon significative, particulièrement en ce qui concerne GAV-ICH et CDV. L'isolation de nouveaux virus en provenance des voies respiratoires a stimulé un intérět renouvelé dans les maladies des voies respiratoires chez les cheins. Le fait qu'un seul virus puisse causer un certain nombre de maladies avec, par exemple GAV-ICH étant associé avec des maladies de la respiration, du foie et des reins tandis que des infections des maladies de voies respiratoires supérieurs peuvent ětre associées à un certain nombre de virus, souligne la complexité des infeptions de virus canins. Bien que de nombreux aspects de la pathogenèse d'infections de virus canins aient été soigneusement étudiés, on espère apporter plus d'attention à beacoup de questions restées sans réponses concernant le rǒle des facteurs immunologiques. Zusammenfassung. Die weitverbreitete Anwendung von verschiedener Technik iwe Elek-tonenmikroskopie und Immunfluoreszenz in der Studie von Hundeviren hat unser Wissen erheblich gesteigert, besonders in Hinsicht auf CAV-ICH und CDV. Die Isolierung von neuen Viren, besonders vom Atefnweg hat émeutes Interesse an der Erkrankung des oberen Luftweges von Hunden, angeregt. Die Tatsache, dass ein einzelner Virus eine Anzahl von Krankheiten verursachen kann, z.B. CAV-ICH ist assoziiert mit Atemweg- Leber- und Nierenerkrankung, wàhrend einige infektionen z.B. obère Atemwegerkrankung mit einer Anzahl von Viren in Verbindung gebracht werden kann, bekràftigt die Verwicklung der Hundevirusinfektionen. Obwohl viele Ansichten der Pathogenese von Hundevirusinfektion sorgfǎltig studiert wurden, hofft man dass mehr Aufmerksamkeit auf die vielen unbeantworteten Fragen gerichtet wird, die die Rolle der immunologischen Faktoren betrifft.