Canine coronavirus in Australian dogs

OBJECTIVE: To estimate the frequency of serum antibodies (IgG and IgM) to canine coronavirus (CCV) in the Australian dog population and evaluate the role of CCV as a causative agent of gastroenteritis. DESIGN: A serological survey of antibodies to CCV among different dog populations. PROCEDURE: The development and characterisation of an indirect ELISA for the detection of antibodies (IgG and IgM) to CCV was undertaken. Sera collected from both diarrhoeal and non-diarrhoeal dogs from various populations throughout Australia were tested for these antibodies to CCV. RESULTS: Serum samples (1396) collected from 1984 to 1998 were tested for the presence of IgG antibodies to CCV. Samples were divided into two categories on the basis of the number of dogs housed together. The groups were either an open population containing dogs housed as groups of three or less, or kennel populations. Sera from 15.8% of the open population and 40.8% of kennelled dogs were positive for CCV antibodies. The prevalence of antibodies varied from zero to 76% in kennelled dogs. About 23% of 128 dogs positive for IgG antibodies to CCV were also positive for IgM antibodies to CCV, indicating recent CCV infection. Of those dogs that were presented with clinical signs of gastroenteritis such as diarrhoea and vomiting (n = 29), 85% were positive in the IgM ELISA and 85.7% in the IgG ELISA for antibodies to CCV. In comparison, for those dogs presented without any history of gastroenteritis only 15% were positive for IgM and 30% positive for IgG. CONCLUSION: Serological evidence indicates that infection with CCV in dogs is widespread throughout the Australian mainland. The prevalence of antibodies varies greatly among different populations, with an average of 40.8% positive in kennelled populations and 15.8% in the open population.     

Clinical remission of idiopathic hypereosinophilic syndrome in a Rottweiler

Idiopathic hypereosinophilic syndrome (HES) is a rare syndrome for which Rottweilers appear to over-represent the canine cases. A 6-month-old female entire Rottweiler presented with seizures following a traumatic incident. The dog was identified as having a marked, sustained eosinophilia and investigations did not identify an underlying cause. Concurrently, the dog had chronic eosinophilic hepatitis with impaired liver function and mesenteric eosinophilic lymphadenitis. The dog went on to have spontaneous resolution of HES and normal liver function was subsequently documented. To date, the dog is still alive, more than 4 years after initial presentation. The diagnosis of idiopathic HES in Rottweilers may not carry a poor prognosis and the condition may spontaneously resolve, even in cases with documented organ damage.     

Protecting effect of vitamin E supplementation on submaximal exercise-induced oxidative stress in sedentary dogs as assessed by erythrocyte membrane fluidity and paraoxonase-1 activity

The aim of this placebo-controlled study was to investigate the effects of oral vitamin E supplementation for 10 weeks on exercise-induced oxidative damage in untrained dogs. Eight dogs were randomly assigned to a supplementation (n = 4) or control (n = 4) group and underwent two isolated submaximal exercise sessions, 10 weeks apart. Blood was collected during each session to measure erythrocyte membrane fluidity (EMF), paraoxonase-1 (PON1) activity, plasma malondialdehyde (MDA) and vitamin E concentrations. These biomarkers were measured in venous blood samples collected before (t₀), just after (t, EMF only) and 1 d (t + 1 d) and 7 d (t + 7 d) after the dogs ran on a treadmill.Prior to vitamin E supplementation, exercise induced a significant decrease in PON1 activity, EMF, vitamin E concentration and a significant increase in MDA concentration at t + 1 d. After a 10 week vitamin E supplementation period, these exercise-induced changes in PON1 activity, EMF and MDA concentration were still significant in the control group, but not in the supplemented group. These results suggested that vitamin E supplementation had a protective effect on submaximal exercise-induced oxidative damage in sedentary dogs.     

Lymphocyte blastogenic responses to inciting food allergens in dogs with food hypersensitivity

Lymphocyte blastogenic responses against food allergens in dogs with food hypersensitivity were evaluated in this study. Eleven dogs with food hypersensitivity, based on food elimination and oral food provocation tests and allergic responses to food allergens, were examined by various tests such as intradermal testing, antigen-specific IgE testing, and lymphocyte blastogenic responses. The number and kinds of food allergens identified as positive by these tests were compared with the offending food allergens that were found in an oral food provocation test. In 9 (82%) of the 11 dogs with food hypersensitivity, there was close agreement for positive allergens between the results of lymphocyte blastogenic responses and oral food provocation test; however, there was little agreement for intradermal and IgE testing of the positive allergens with those of the oral food provocation test (11% and 31%, respectively). In the 9 dogs, the stimulation indices of lymphocyte blastogenic responses increased to 2.0-10.1 upon food provocation but decreased significantly to 0.7-1.4 upon feeding the elimination diet until clinical signs disappeared. These results indicate that lymphocyte blastogenic responses may fluctuate because of exposure to offending food allergens in dogs with food hypersensitivity. Lymphocytes reactive to food allergens may play an important role in the pathogenesis of food hypersensitivity in dogs.     

Hemolytic-uremic syndrome in a dog

A 3-year-old, spayed, female Boxer was presented because of acute onset of anorexia, vomiting, and hemorrhagic diarrhea. Microangiopathic hemolytic anemia with intravascular hemolysis, thrombocytopenia, and acute renal failure were detected. The dog was treated with fluids, antiemetics, antibiotics, and diuretics. Despite supportive therapy, the dog's condition worsened, and the owners elected euthanasia. Necropsy revealed disseminated petechiae on the parietal peritoneum and serosal surfaces of the intestinal tract. The histologic lesions were consistent with severe arteritis and microvascular thrombosis involving only the renal and intestinal arterioles. The final diagnosis was hemolytic-uremic syndrome (HUS), a rarely described disorder in dogs. The clinical presentation of primarily gastrointestinal clinical signs was similar to that of typical or diarrhea-associated HUS (D+ HUS) in humans (mainly children), which is caused by gastrointestinal proliferation of verocytotoxin-producing Escherichia coli. Bacterial toxins can be adsorbed and cause endothelial injury, activation of hemostasis, and thrombosis, with lesions confined primarily to the kidneys. Although rare, HUS should be considered in the differential diagnosis of dogs with microangiopathic hemolytic anemia.     

Physiologic VDD versus nonphysiologic VVI pacing in canine 3rd-degree atrioventricular block

Historically, ventricular demand, nonphysiologic (VVI) pacing has been the most commonly used modality to treat 3rd-degree atrioventricular (AV) block. The goal of this study was to determine the feasibility of using a commercial, single-lead, physiologic (VDD) pacemaker in dogs with 3rd-degree AV block. Furthermore, we hoped to characterize and identify differences in the radiographic, echocardiographic, neurohormonal, and quality of life consequences of physiologic versus nonphysiologic pacing. We evaluated 10 dogs during a 12-week crossover study. Acutely, rate-matched physiologic pacing reduced pulmonary capillary wedge pressure by 19% compared with nonphysiologic pacing. VDD pacing significantly reduced left atrial size normalized to body weight, left atrial-to-aortic root ratio, and left ventricular end-systolic dimension and increased fractional shortening, aortic Doppler velocity, cardiac output, and stroke volume compared with VVI pacing. Variable rate VDD pacing resulted in a significantly slower heart rate (HR) during echocardiography than fixed-rate (100 bpm) VVI pacing. AV synchronous pacing reduced circulating N-terminal proatrial natriuretic peptide (ANP), norepinephrine (NOR), and epinephrine (EPI) concentrations compared with asynchronous pacing. There were no significant differences in systemic blood pressure, thoracic radiographs, or owner-perceived quality of life. The median percentage of AV synchronous pacing during the VDD modality was 99.8% (range, 1.2 to 99.9%). This study confirms the potential to achieve physiologic pacing with a commercial, single-lead system in dogs. VDD pacing improved hemodynamics and neurohormonal profiles over asynchronous pacing although the long-term clinical benefits of these changes remain to be determined.     

Molecular detection of Hepatozoon canis in dogs and ticks in Shaanxi province,China

Hepatozoon canis, transmitted by Rhipicephalus sanguineus, is a tick-borne pathogen and causes canine hepatozoonosis. Until now, only limited previous studies were conducted on the molecular detection and characterization of Hepatozoon sp. in dogs in China. Blood samples were collected from 93 sick dogs that were clinically diagnosed as babesiosis but tested negative for Babesia, and 103 apparently healthy dogs, as well as their infesting ticks in Xi’an and Hanzhong cities, Shaanxi province of China. PCR amplifying partial 18S rRNA gene was used to detect the DNA of Hepatozoon sp. Genetic and phylogenetic analysis were performed to determine the Hepatozoon species. Our results demonstrated that H. canis was identified from the sick dogs and the infested ticks in Hanzhong, with no significant differences of prevalence between both genders and ages. No positive blood or tick samples were found in Xi’an. Moreover, all the 18S rRNA gene sequences recovered from both dogs and the infested ticks showed a high genetic similarity with each other, and also presented a close relationship with other known sequences in and outside China. In conclusion, H. canis was identified in babesiosis-suspected dogs and ticks infesting them in Shaanxi, China, although the association between clinical signs and H. canis need further study.     

Molecular investigation on the presence of canine parvovirus in Egypt

Canine parvovirus type 2 (CPV-2) causes a highly contagious gastroenteritis disease of dogs and wild canids. To investigate the CPV-2 prevalence in Dakahlia Governorate, Egypt, a total of 50 fecal swabs were collected from suspected diseased dogs during 2016–2017. Out of 50 collected samples, 35 samples (70 %) presented positive results for CPV-2 using immuno-chromatography (IC) as a rapid test. CPV-2DNA was detected in 42 samples (84 %) by using polymerase chain reaction (PCR). The frequencies of CPV-2 were significantly higher in German shepherd breed (46 %; 23/50) and in age groups less than 6 months (76%; 38/50). We evaluated the breed, age, sex, rapid test results and clinical signs as predictors for classification of animal status into infected and not infected. The best predictors for classification process were rapid test result and clinical signs. Both CPV-2b and CPV-2c subtypes were detected by CPV2-VP2 gene sequences analysis. Deduced amino acid sequences alignment showed substitutions at 3 sites (Arg453Pro, Ala574Glu and Gln457Leu). Further investigations are needed to reveal the genetic and antigenic relation between field and vaccinal strains of CPV-2 in Egypt.     

The spatial distribution of atopic dermatitis cases in a population of insured Swedish dogs

Canine atopic dermatitis (CAD) is manifested by pruritus and inflammation of the skin, and most affected dogs have specific IgE against environmental allergens. Our aim was to evaluate whether in Sweden the incidence of CAD varies spatially, and to investigate possible environmental causes of such variation in a longitudinal study of CAD incidence among insured Swedish dogs. The dataset consisted of >220,000 individuals which had been covered by an insurance plan between January 1, 1995 and December 31, 2002. Out of these, 1235 CAD cases were identified and matched to postal-code areas based upon the address of the owner. Environmental risk factors we considered included averages of long-term annual rainfall, and of January and July temperatures. Initial visualization of the incidence rate of CAD (cases/dog-years at risk) expressed as empirical Bayes smoothed spatial rates indicated geographic variation. Moran's I, adjusted for population at risk, revealed significant global clustering. Both the spatial scan statistic and a local indicator of spatial autocorrelation revealed a higher incidence of CAD in the major cities. In a Poisson-regression model (with a spatial covariance structure), the incidence of CAD increased with increasing human population density, increasing average annual rainfall, living in the southern half of Sweden, and having a veterinary dermatologist in the county.     

Investigation and Analysis of Porcine Epidemic Diarrhea Virus,Transmissible Gastroenteritis Virus and Pseudorabies Virus of Swine Diarrhea Cases in Shandong Province

To understand porcine viral diarrhea prevalence in the large-scale pig farms of Shandong province, a total of 3 035 clinical samples were detected by PCR from January, 2014 to December, 2016.Those samples were detected for porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV) and pseudorabies virus (PRV). The results showed that the detection rate of PEDV, PRV and TGEV were 67.49%, 9.33% and 3.29%, respectively.During the past three years, the lowest detection rate of PEDV was 48.15% in the fourth quarter of 2014,and the highest was 88.57% in the fourth quarter of 2015.In 2016,the detection rate represented fluctuate declining compared with 2015.The highest positive rate of TGEV was 18.52% in the fourth quarter of 2014,and in the third quarter of 2015 was 15.38%.The lowest positive rate of TGEV was 6.67% in the first quarter of 2016 and TGEV was not detected in the other quarters. The highest detection rate of RPV was 15.68% in the second quarter of 2016,and the lowest was 2.56% in the second quarter of 2014,except the first quarter of 2014 that the PRV was 0. By detecting three kinds of viruses in 69 clinical samples collected passively, the results showed that the detection rate of PEDV,TGEV and PRV were 86.96%,5.80% and 37.68%,respectively. The total single infection rate was 69.57%,the single infection rates of PEDV,TGEV and PRV were 57.97%,1.45% and 10.14%, respectively;The total mixed infection rate was 30.43%,the mixed infection rates of PEDV/PRV,PEDV/TGEV and TGEV/PRV were 26.09%,2.90% and 1.45%, respectively;Obviously, the total single infection rate was higher than the total mixed infection rate. The results showed that the PEDV, PRV and TGEV were prevailing in Shandong province. There were PEDV/TGEV, TGEV/PRV, PEDV/PRV mixed infection, and the number of PEDV/PRV mixed infection was in the majority. However, there was no PEDV/PRV/TGEV mixed type infection. At present, PEDV was the major pathogen of porcine viral diarrhea and the test results could provide the reference to the diagnosis of porcine viral diarrhea.     

山东省猪腹泻病例中PEDV、TGEV和PRV的感染调查与分析

为了解山东省规模化猪场由猪流行性腹泻病毒（PEDV）、猪传染性胃肠炎病毒（TGEV）和猪伪狂犬病毒（PRV）引起猪病毒性腹泻的流行情况,自2014年1月至2016年12月,对来自山东省各地规模化猪场的猪腹泻病料（共3 035份）进行PCR检测。结果显示,PEDV、PRV和TGEV阳性率分别为67.49%、9.33%和3.29%;3年间,PEDV阳性率在2014年第四季度最低,为48.15%,2015年第四季度阳性率最高,为88.57%,2016年各季度阳性率相对2015年呈波动下降趋势;TGEV阳性率在2014年第四季度最高,为18.52%,2015年第三季度阳性率为15.38%,2016年第一季度阳性率为6.67%,其他季度未检测出阳性病料;PRV阳性率在2016年第二季度最高,为15.68%,除2014年第一季度未检出阳性病料外,2014年第二季度阳性率最低,为2.56%。通过对69份被动送检的病料进行PEDV、TGEV和PRV混合感染检测发现,这部分病料中PEDV、TGEV、PRV阳性率分别为86.96%、5.80%和37.68%;总单独感染率为69.57%,PEDV、TGEV和PRV单独感染率分别为57.97%、1.45%和10.14%;总混合感染率为30.43%,PEDV/PRV、PEDV/TGEV和TGEV/PRV混合感染率分别为26.09%、2.90%和1.45%;总单独感染率比总混合感染率高。结果表明,山东省存在PEDV、PRV和TGEV 3种病毒流行,存在PEDV/TGEV、TGEV/PRV和PEDV/PRV的混合感染,混合感染中主要为PEDV/PRV混合感染,不存在PEDV/PRV/TGEV的混合感染。目前PEDV是引起山东省猪病毒性腹泻的主要病因,本试验结果可为山东省猪病毒性腹泻的诊断和控制提供参考。     

Effects of β‐carotene‐enriched dry carrots on β‐carotene status and colostral immunoglobulin in β‐carotene‐deficient Japanese Black cows

Data from 18 β‐carotene‐deficient Japanese Black cows were collected to clarify the effects of feeding β‐carotene‐enriched dry carrots on β‐carotene status and colostral immunoglobulin (Ig) in cows. Cows were assigned to control or carrot groups from 3 weeks before the expected calving date to parturition, and supplemental β‐carotene from dry carrots was 138 mg/day in the carrot group. Plasma β‐carotene concentrations in the control and carrot groups at parturition were 95 and 120 μg/dL, and feeding dry carrots slightly improved plasma β‐carotene at parturition. Feeding dry carrots increased colostral IgA concentrations in cows and tended to increase colostral IgG₁, but colostral IgM, IgG₂, β‐carotene and vitamin A were not affected by the treatment. Feeding dry carrots had no effects on plasma IgG₁, IgA and IgM concentrations in cows, but plasma IgG₁ concentrations decreased rapidly from 3 weeks before the expected calving date to parturition. These results indicate that feeding β‐carotene‐enriched dry carrots is effective to enhance colostral IgA and IgG₁ concentrations in β‐carotene‐deficient cows.     

蒺藜苜蓿E3泛素连接酶U-box基因克隆及表达分析

泛素化在植物生长和发育过程中起重要作用,E3泛素连接酶负责对靶蛋白特异性识别,其中U-box结构的E3泛素连接酶具有调控植物生长发育和免疫反应等功能,并在抗逆性方面发挥作用。目前,关于蒺藜苜蓿U-box家族基因的研究尚未见报道。本研究从蒺藜苜蓿中克隆得到U-box(MtPUB4)基因,该基因cDNA全长2448bp,编码815个氨基酸,包括1个U-box结构(C-X2-H-X7-C-X7-C-X2-C-H-X2-H)和5个ARM结构域,属于U-box/ARM类型E3泛素连接酶。构建原核表达载体pET-MtPUB4,通过聚丙烯酰胺凝胶电泳(SDS-PAGE)表明在大肠杆菌中表达了MtPUB4蛋白。荧光定量PCR分析表明MtPUB4基因在蒺藜苜蓿花中的表达量最高,在根中表达量最低。MtPUB4基因受到NaCl、聚乙二醇、脱落酸诱导,随着诱导时间增加,表达量呈现出增长趋势。这些结果表明,MtPUB4基因在蒺藜苜蓿生长发育和抗逆性中可能起到重要调节作用,但在低温胁迫中表达量稍微下降,变化不明显。本研究成功构建了pBI121-MtPUB4植物表达载体,为进一步转化拟南芥突变体Atpub4奠定了基础。