Soremouth in sheep and goats at the Mankon Animal Research Station, Cameroon.

Between 1980 and 1989, a survey was carried out to appreciate the prevalence of the soremouth (orf) disease among sheep and goat flocks at the Mankon Research Station (Cameroon). The results showed that orf is enzootic at the station and is more a goat (85.5%) than a sheep disease (51%) with kids showing a higher susceptibility rate (53%) than adult goats. Orf has a high mortality (80-90%) with a negligible mortality rate (2%). Both sexes were affected while more incidences of orf were recorded during the dry season than in the rainy season.     

Isolation and characterization of orf viruses from Korean black goats

Five cases of orf virus infection in Korean black goats were diagnosed in our laboratory between 2010 and 2011. One orf virus (ORF/2011) was isolated from an ovine testis cell line (OA3.Ts) for use as a vaccine candidate. Sequences of the major envelope protein and orf virus interferon resistance genes were determined and compared with published reference sequences. Phylogenetic analyses revealed that orf viruses from Korean black goats were most closely related to an isolate (ORF/09/Korea) from dairy goats in Korea. This result indicates that the orf viruses might have been introduced from dairy goats into the Korean black goat population.     

In vivo T-cell subset depletion suggests that CD4+ T-cells and a humoral immune response are important for the elimination of orf virus from the skin of sheep

In vivo lymphocyte subset depletion offers a unique opportunity to study the roles of different cellular components of the immune system of sheep during infection with orf virus. Lambs were depleted of specific lymphocyte subsets by the intravenous administration of monoclonal antibodies against ovine lymphocyte surface markers and then challenged with orf virus. The skin lesions that developed were scored visually as to their severity. Blood samples were collected to monitor the lymphocyte depletions and to measure orf-virus-specific antibody levels. Skin biopsies were collected from the lesion site and studied to determine the course of the infection and the presence of various cell types and orf virus.All the sheep developed orf virus lesions after infection. All three of the CD4-depleted lambs were unable to clear virus from their skin and did not have an antibody response to the virus. Virus was also detected in the skin of one each of the three CD8-depleted, WC1-depleted and control sheep on the final day of the trial. CD8(+) lymphocytes did not appear to be essential for viral clearance later in the infection. Depletion of the majority of gammadelta(+) T-cells did not affect the outcome of orf virus infection. In sheep with high orf-virus-specific antibody titres at the time of infection, orf lesions healed faster than lesions in sheep with low antibody levels, and this occurred regardless of the lymphocyte depletion status of the animals.This study suggests that the presence of CD4(+) T-cells and orf-virus-specific antibodies are important for the control of viral replication in the skin of infected sheep.     

Detection of contagious ovine ecthyma (orf) and risk factors for infection in small ruminants in Iran

The primary cause of contagious ecthyma is the orf virus, the parapoxvirus prototype. It is a viral problem observed in goat and sheep flocks in Iran, causing economic loss. Orf is a zoonosis with little epidemiological investigation present in Iran. The current research aims at determining the status of this virus, and a PCR was used as a confirmatory instrument. We sampled 668 goats and sheep and various breeding systems. Besides, the orf prevalence was studied, and vaccination efficacy was determined. Moreover, the potential risk factors surveyed for infection with ecthyma were identified. Samples were taken from goat and sheep flocks in the present cross-sectional research, and PCR was used for testing orf DNA. A checklist including animals’ general information was completed. Data were analyzed using univariate tests (chi-square and t-tests) and multivariable binary logistic regression analysis. Three hundred one (45%) goats and sheep detected orf DNA. The age of 70% of positive cases was below one month. Ecthyma infection was significantly higher in imported breeds (87.3%) than indigenous (39.3%). Ninety-six percent of infected goats and sheep in the present work were not vaccinated against ecthyma. The high prevalence of the orf virus was confirmed among goat and sheep flocks in Iran. It is necessary to train ranchers regarding sanitary actions, quarantine, and application of orf vaccination plans.     

Development of a contagious ecthyma vaccine for goats

OBJECTIVE: To identify a strain of contagious ecthyma virus from goats that possesses the appropriate characteristics for an effective vaccine for goats. ANIMALS: 25 goat kids used for vaccine development and 100 goat kids used for evaluation of vaccine efficacy. PROCEDURES: 5 strains of contagious ecthyma virus were tested in a vaccination-challenge study to identify the best strain to be the seed strain for a contagious ecthyma vaccine. The vaccine derived from the chosen viral stain was tested at 2 concentrations for efficacy in a vaccination-challenge study. RESULTS: 2 of 5 viral strains induced moderate to severe scabs following infection, and 3 viral strains protected the goats from wild-type virus challenge following vaccination. Viral strain 47CE was selected as the seed source for the production of a contagious ecthyma vaccine because of the larger vaccine-to-challenge scab formation ratio. Vaccine 47CE protected all goat kids (48/48) following challenge with the wild-type contagious ecthyma virus; all goat kids (32/32) in the control group had scab formation following challenge with the wild-type contagious ecthyma virus, which indicated no protection following administration of vaccine diluent. CONCLUSIONS AND CLINICAL RELEVANCE: A vaccine containing a caprine strain of contagious ecthyma virus used in goats appeared to provide the characteristics needed for an effective vaccine, including good scab production and protection from wild-type infection. This vaccine may potentially provide better protection for goats from contagious ecthyma than currently available vaccines labeled for sheep.     

Molecular characterization of lentiviruses from goats from Poland based on gag gene sequence analysis

Caprine arthritis-encephalitis virus (CAEV) infection in goats is worldwide but with higher prevalence in industrialized countries. While positive serology of CAEV in Polish goats was reported there was no genetic study of this virus. In this study, we described the molecular characterization of lentiviruses isolated from seropositive goats from Poland. We cloned and sequenced a fragment from the gag gene covering part of the coding sequences for the matrix (MA) p17 and for the capsid (CA) p25 proteins. Resulting nucleotide sequences were aligned with those from other ovine/caprine lentivirus isolates. We present data showing that the sequences of most goat lentivirus isolates are closer to the prototypic CAEV-Co isolate, nevertheless from one goat we isolated a virus that is closer to the sheep Maedi Visna virus (MVV) isolate. This might indicate a recent cross-species infection from sheep to goat.     

LEUCOENCEPHALOMYELITIS OF GOAT KIDS

SUMMARY A leucoencephalomyelitis in 6 goat kids 2 to 5 months old is described. The disease was characterised by fever, ataxia, posterior paresis, circling and hyperaesthesia progressing to prostration. The neural lesion was confined to the white matter of the cerebellum and posterior brain stem in 4 kids, but in 2 others the cervical spinal cord was the main site affected. The lesion was characterised microscopically by dense perivascular cuffing with mononuclear cells, infiltration of the parenchyma with macrophages and a proliferation of glial cells and by a marked primary demyelination. In more advanced lesions, areas of the neurophil were replaced by a loose glial scar. There were associated pulmonary lesions of interstitial pneumonitis and hyperplasia of the peribronchiolar lymphoid tissue. Attempts to isolate an aetiological agent and to transmit the disease to young goat kids and lambs were unsuccessful. The disease has not been reported before in Australia but has distinct similarities to an infectious leucoencephalomyelitis of young goats which has been described in North America.     

Caprine arthritis-encephalitis syndrome (CAE): a review

Caprine arthritis-encephalitis syndrome (CAE) is a viral disease of domestic goats characterized by chronic proliferative synovitis and periarthritis of adult goats while acute afebrile leukoencephalomyelitis is characteristic in goat kids. The causative agent, a Lentivirus, is transmitted from adult goats to kids via the colostrum or lateral transmission also occurs. The CAE virus is worldwide in distribution. All breeds and ages of goats are susceptible to infection, and once established it persists throughout the animal's life. A diagnosis can be based on the clinical signs, pathological changes, and demonstration of serum antibody levels. A vaccine is not available. Control or eradication of the disease is based on periodic serological testing, culling of all CAE antibody-positive animals, and separation of kids from adults following birth.     

Transmission of caprine herpesvirus 2 in domestic goats

Caprine herpesvirus 2 (CpHV-2) is a recently recognized gammaherpesvirus that is endemic in domestic goats and has been observed to cause clinical malignant catarrhal fever (MCF) in certain species of deer. In this study, transmission of CpHV-2 in goats was examined. A total of 30 kids born to a CpHV-2 positive goat herd were selected and divided into two groups: group 1 (n=16) remained in the positive herd; group 2 (n=14) was separated from the herd at 1 week of age after obtaining colostrum. Peripheral blood samples from each kid were examined regularly by competitive ELISA for MCF viral antibody and by PCR for CpHV-2 DNA. Fifteen out of 16 goats (94%) that remained with the positive herd seroconverted and became PCR-positive for CpHV-2 by 10 months of age. In contrast, all kids (100%) that were separated from the positive herd at 1 week of age remained negative until termination of the experiment at 1 year of age. Additional transmission experiments revealed that all CpHV-2-free adult goats were susceptible to CpHV-2 or ovine herpesvirus 2 (OvHV-2) infection. The data indicate that the transmission pattern of CpHV-2 in goats is similar to the pattern of OvHV-2 in sheep and that CpHV-2-free goats can be established by early separation of kids from positive herds, which has significant implications for MCF control programs.     

Differences in signs and lesions in sheep and goats with enterotoxemia induced by intraduodenal infusion of Clostridium perfringens type D

Enterotoxemia was induced in 4 lambs and 4 goat kids by continuous intraduodenal infusion of a whole culture of Clostridium perfringens type D. Clinical signs, hematologic values, biochemical alterations, and postmortem lesions in the lambs and goat kids were compared. The 4 lambs and 4 goat kids died within 25 hours of beginning the infusions. Lesions were not observed in the gastrointestinal tract of the 4 lambs; however, severe hemorrhagic enterocolitis was found in the 4 goat kids. This difference between the lambs and goat kids in the lesions caused by experimentally induced enterotoxemia may explain the discrepancies reported between sheep and goats in clinical signs, response to treatment, and efficacy of vaccination observed in naturally induced enterotoxemia in the 2 species.     

Characterization of bovine herpesviruses isolated from six sheep and four goats by restriction endonuclease analysis and radioimmunoprecipitation

Viral DNA from 10 herpesviruses isolated from 6 sheep and 4 goats were examined by restriction endonuclease analysis with respect to their relatedness to one another; to bovine herpesvirus type 6 (BHV-6), also known as caprine herpesvirus; and to 2 strains of bovine herpesvirus type 1 (BHV-1), known as infectious bovine rhinotracheitis virus (IBRV) and infectious pustular vulvovaginitis virus (IPVV). Viral proteins from the isolates were examined by radioimmunoprecipitation with anti-BHV-1/IBRV gnotobiotic calf (bovine) serum, anti-BHV-1/IBRV bovine hyperimmune serum, and anti-BHV-6 rabbit serum to evaluate their antigenic relatedness to each other. The goat isolates were obtained from animals with various disease conditions including respiratory tract disorders, vulvovaginitis, and wart-like lesions on the eyelid. The other isolates were from domestic sheep and came from aborted fetuses or from sheep with fatal pneumonia or proliferative lesions around lips and nose. All of the goats and 4 of the sheep from which the viral isolates were obtained had comingled with cattle. Purified DNA from each of the 10 field isolates and from BHV-1/IBRV, BHV-1/IPVV, and BHV-6 caprine herpesvirus was cleaved with restriction endonuclease Pst I. Five of 6 sheep isolates and 3 of 4 goat isolates yielded unique restriction patterns, ie, patterns that differed from each other by one or more bands. Sheep isolate DNA patterns were different from goat isolate patterns, and all restriction endonuclease analysis patterns were similar to the pattern for BHV-1/IBRV, but different from that for BHV-1/IPVV or for BHV-6.(ABSTRACT TRUNCATED AT 250 WORDS)     

Toggenburg Orbivirus, a new bluetongue virus: Initial detection, first observations in field and experimental infection of goats and sheep

A novel bluetongue virus termed “Toggenburg Orbivirus” (TOV) was detected in two Swiss goat flocks. This orbivirus was characterized by sequencing of 7 of its 10 viral genome segments. The sequencing data revealed that this virus is likely to represent a new serotype of bluetongue virus [Hofmann, M.A., Renzullo, S., Mader, M., Chaignat, V., Worwa, G., Thuer, B., 2008b. Genetic characterization of Toggenburg Orbivirus (TOV) as a tentative 25th serotype of bluetongue virus, detected in goats from Switzerland. Emerg. Infect. Dis. 14, 1855–1861].In the field, no clinical signs were observed in TOV-infected adult goats; however, several stillborn and weak born kids were reported. Although born during a period of extremely low vector activity, one of these kids was found to be antibody and viral genome positive and died 3.5 weeks postpartum.Experimental infection of goats and sheep, using TOV-positive field blood samples, was performed to assess the pathogenicity of this virus.Goats did not show any clinical or pathological signs, whereas in sheep mild bluetongue-like clinical signs were observed. Necropsy of sheep demonstrated bluetongue-typical hemorrhages in the wall of the pulmonary artery. Viral RNA was detected in organs, e.g. spleen, palatine tonsils, lung and several lymph nodes of three experimentally infected animals.Unlike other bluetongue virus serotypes, it was not possible to propagate the virus, either from naturally or experimentally infected animals in any of the tested mammalian or insect cell lines or in embryonated chicken eggs.In small ruminants, TOV leads to mild bluetongue-like symptoms. Further investigations about prevalence of this virus are needed to increase the knowledge on its epidemiology.     

羊痘的研究进展

羊痘病毒能引起山羊痘、绵羊痘和牛的结节性疹块病。羊痘是以发热、全身性的皮肤损伤、痘疹和淋巴结病变为特征。羊痘病毒是所有动物痘病毒中最为重要的一种，严重影响养羊业和国际贸易的发展。本文从病原学、流行病学、诊断和预防控制等方面对羊痘做一综述。虽然此病从临床症状和宿主特异性上很容易做出诊断，但进一步的实验室确诊还是必要的，现已有多种检测方法和诊断试剂。控制该病最有效的方法还是使用疫苗对易感动物进行免疫接种。     

Caprine arthritis-encephalitis syndrome (CAE): A review

Caprine arthritis-encephalitis syndrome (CAE) is a viral disease of domestic goats characterized by chronic proliferative synovitis and periarthritis of adult goats while acute afebrile leukoencephalomyelitis is characteristic in goat kids. The causative agent, a Lentivirus, is transmitted from adult goats to kids via the colostrum or lateral transmission also occurs.The CAE virus is worldwide in distribution. All breeds and ages of goats. are susceptible to infection, and once established it persists throughout the animal's life. A diagnosis can be based on the clinical signs, pathological changes, and demonstration of serum antibody levels.A vaccine is not available. Control or eradication of the disease is based on periodic serological testing, culling of all CAE antibody-positive animals, and separation of kids from adults following birth.Kansas Agriculture Experiment Station Contribution #84-148-J.     

Isolation of an adenovirus and an adeno-associated virus from goat kids with enteritis.

A dairy goat operation in Minnesota experienced a sudden, markedly increased mortality among its neonatal goats. Approximately 60 of 130 kids (46%) died. The animals had diarrhea and dyspnea of 1-2 days duration before death. Necropsy of 4 goat kids revealed marked, acute, catarrhal enteritis and fibrinous pleuropneumonia. Mannheimia haemolytica was isolated from the lungs. Basophilic inclusion bodies filling the entire nucleus were present in enterocytes of the ileum of 3 goats. Adenoviral particles were detected in the feces by electron microscopy and adenovirus was subsequently isolated from the intestinal content together with a parvo-like virus (dependovirus). Morphology, physicochemical characteristics, and neutralization tests indicated that the adenovirus resembled ovine adenovirus-2 (OAdV-2). However, the PstI restriction endonuclease pattern produced by the goat adenovirus was distinct from that of OAdV-2. This is the first report of enteritis in goats with an adenovirus antigenically related to OAdV-2 and with a parvo-like dependovirus.     

Transmission of virulent footrot between sheep and goats

OBJECTIVE: To determine the infectivity of ovine and caprine strains of Dichelobacter nodosus for both sheep and goats. DESIGN: Pen experiments in which 20 sheep and 19 goats were challenged directly with the two strains, and transmission experiments on pasture, using donors infected by experimental challenge. RESULTS: Sheep and goat strains of D nodosus infected both animal species in experimental challenges. Animals so infected transmitted footrot to both sheep and goats on pasture plots. A significantly smaller proportion of goats than sheep was infected when challenged with either strain. The interval between exposure and development of footrot in goats was longer than in sheep when recipient animals were exposed to infected donors on pasture. The disease was less invasive in goats than in sheep. CONCLUSIONS: With the strains of D nodosus used there was no evidence of host specificity. Direct transmission of footrot can occur between sheep and goats in the same environment. There is a need to include goats in ovine footrot eradication programs and vice versa.     

Vulvovaginitis of goats due to a herpesvirus

Two concurrent outbreaks of genital disease in goats were associated with infection by a herpesvirus that was isolated from vulval and vaginal lesions of affected does. Serum neutralising antibody to the virus was present both in goats with the clinical disease and some unaffected goats. Of 19 goat herds examined only 4 had serum neutralising antibody positive goats with low (5%) to high (60%) incidence of infection. The virus isolate was characterised as a herpesvirus on its physico-chemical and morphological features. It contained DNA and was inactivated at low pH and by treatment with lipid solvents and trypsin. The virus particles were icosahedral, consisting of a nucleocapsid surrounded by an envelope membrane and measured approximately 150 nm in diameter. The virus was serologically related to a New Zealand isolate of caprine herpesvirus (NZ-CpHV), associated with similar genital disease, and was distinct from bovine herpes virus-1 (BHV-1) showing a one way neutralisation pattern.     

Detection of cellular cytokine mRNA expression during orf virus infection in sheep: differential interferon-gamma mRNA expression by cells in primary versus reinfection skin lesions.

In sheep infected with the parapoxvirus orf virus, primary infection orf skin lesions developed and resolved within 8 weeks. Reinfection lesions were smaller and resolved within 3 weeks. The host response in the skin was characterized by an accumulation of neutrophils, dendritic cells, CD4+ T cells, CD8+ T cells, B cells and T19+ gammadelta T cells. The magnitude of this accumulation paralleled orf virus replication in the skin. In situ hybridization was used to detect cells expressing interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha) and interleukin-4 (IL-4) mRNAs in orf skin. Cells expressing IL-4 mRNA were not detected at any time after infection. Cells expressing IFN-gamma mRNA were detected after reinfection but not after primary infection. Cells expressing TNF-alpha mRNA included epidermal cells, vascular endothelium and uncharacterized cells that increased more rapidly in the skin after reinfection compared to primary infection. The results are consistent with a prominent role for IFN-gamma in the host immune response controlling the severity of the disease.     

Transplacental BVD virus transmission after experimental inoculation of goats in different pregnancy stages

Eight groups of altogether 25 goats without neutralizing antibodies against BVD virus, were inoculated either intranasally or intranasally and subcutaneously with two different BVD virus isolates during different stages of gestation. In all 18 goats inoculated within the first 78 days of gestation an abortion and foetal death rate of approximately 100% occurred. Only one goat gave birth to a clinically healthy kid. The other seven goats which were inoculated after the 78th day of gestation showed also a high foetal death rate. Only two of them gave birth to clinically healthy kids. Neutralizing antibodies against BVD virus could be detected in blood samples drawn from 14 kids born at normal term including stillborn and non-viable offsprings. BVD virus was reisolated from different organs taken from seven foetuses. It was not possible to isolate BVD virus from any of the normal offsprings.