Serological indication for persistence of bovine respiratory syncytial virus in cattle and attempts to detect the virus

To identify putative persistent bovine respiratory syncytial virus (BRSV) infections in cattle, seven cattle that had experienced BRSV infections were treated with corticosteroids for two periods of 5 days. During the 5-day periods and the 3 weeks after treatment, attempts were made to isolate BRSV from lung lavage fluid and nasal swab specimens. Fluorescent antibody tests were used to detect BRSV antigen in lung lavage cells. A BRSV specific polymerase chain reaction (PCR) assay was developed, and was performed on lung lavage samples of all seven cattle as well as on various tissues of five of the cattle. In addition, nasal swabs of 74 over-one-year-old cattle, in a closed dairy herd were also assayed by PCR. The virus or its RNA was not detected in putative carriers, by any of the methods used, whereas all positive controls were positive. After corticosteroid treatment, three of the seven cattle showed a fourfold rise in antibody titre, suggesting induction of virus replication. BRSV-seronegative sentinel calves, that were housed together with each corticosteroid-treated animal, did not develop antibodies to BRSV indicating that BRSV was not shed by corticosteroid-treated cattle, or was shed at a very low level. In addition BRSV was not detected in seropositive cattle in a closed farm in summer. Although we consider the rises in antibody titres against BRSV an indication for persistence of BRSV in cattle, BRSV or its RNA was not detected in infected cattle.     

Mixed gonadal dysgenesis. Association with unilateral testis and XY chromosome complement

During all of 1974, we surveyed, for illnesses and deaths, about 407,000 yearling feedlot cattle. From the 3,943 dead cattle, 1,988 necropsies were made; of this number, 31 (1.6%) had ulcers with fatal perforations or hemorrhages; a similar additional number of necropsied cattle had innocuous ulcers as incidental findings. Ulcers developed during all seasons and all stages of fattening, but were more common during the first 45 days of winter-initiated fattening than during other times. Perforations of the abomasal wall resulted in spillage of abomasal contents into the abdominal cavity and the development of peritonitis.     

The serological diagnosis of bovine brucellosis: an evaluation of the complement fixation, serum agglutination and rose bengal tests

In a collaborative investigation in which 4 laboratories took part, the Rose Bengal Test (RBT), Serum Agglutination Test (SAT) and 4 different Complement Fixation (CFT) techniques were evaluated in selected cattle for the diagnosis of bovine brucellosis, by comparing the results they gave with the bacteriological examination of a selection of lymph nodes taken from the same animals at slaughter. The RBT correctly classified all but 1 of 79 culture-positive cattle, but was more often positive in culture-negative animals than the other tests. The RBT may be most useful as a screen test. 11% of the culture-positive cattle had SAT titres below 100 iu and almost 4% of them had less than 30 iu. However, the SAT was more effective in cattle vaccinated with the 45/20 vaccine. The CFT, in 1 of 4 techniques used, identified all of the culture-positive cattle at a serum dilution of 1/4 or above and was considered to be far superior to the SAT as a diagnostic test, except perhaps in cattle vaccinated with the 45/20 vaccine.     

Humoral response of dairy cattle to spirochetes isolated from papillomatous digital dermatitis lesions

OBJECTIVE: To determine whether a humoral response against spirochetes isolated from papillomatous digital dermatitis (PDD) lesions is elicited in dairy cattle affected with PDD. SAMPLE POPULATION: 41 cattle with PDD from 8 dairies (study population) and 30 cattle from 2 dairies free of PDD (control population). Additionally evaluated were 32 cattle from a dairy with a past history of PDD but no current disease, and 52 cattle from a dairy with high prevalence of PDD, 25 with and 27 without detectable lesions. PROCEDURE: ELISA were used to evaluate the humoral response of all cattle to representative isolates from 2 groups of spirochetes of unknown species isolated from PDD lesions. Specificity of the response was evaluated, using immune sera prepared against each of the spirochetes, and by adsorption studies of immune and field sera. The potential for confounding by an antibody response to other spirochetes associated with diseases of cattle was assessed. RESULTS: The antibody response (specific) to both PDD spirochete groups of cows with PDD was significantly increased, compared with that of cows from PDD-free dairies. There was no association between antibody response to PDD-associated spirochetes and antibody response to other spirochetal diseases of cattle. None of the cattle from the dairy with previous history of PDD but without current disease were classified as test positive by either PDD ELISA. There was a significant (P < 0.01) difference in classification results for both PDD ELISA for cattle with PDD from the dairy with a high herd prevalence of PDD, compared with cattle without detectable disease from the same dairy. CONCLUSIONS AND CLINICAL RELEVANCE: The humoral response in cattle with PDD lesions was significantly different from that in cattle without detectable lesions, thus providing additional information regarding the potential role of spirochetes isolated from PDD lesions in the etiopathogenesis of PDD.     

Microsatellite DNA variation and the evolution, domestication and phylogeography of taurine and zebu cattle (Bos taurus and Bos indicus)

Genetic variation at 20 microsatellite loci was surveyed to determine the evolutionary relationships and molecular biogeography of 20 different cattle populations from Africa, Europe and Asia. Phylogenetic reconstruction and multivariate analysis highlighted a marked distinction between humpless (taurine) and humped (zebu) cattle, providing strong support for a separate origin for domesticated zebu cattle. A molecular clock calculation using bison (Bison sp.) as an outgroup gave an estimated divergence time between the two subspecies of 610,000-850,000 years. Substantial differences in the distribution of alleles at 10 of these loci were observed between zebu and taurine cattle. These markers subsequently proved very useful for investigations of gene flow and admixture in African populations. When these data were considered in conjunction with previous mitochondrial and Y chromosomal studies, a distinctive male-mediated pattern of zebu genetic introgression was revealed. The introgression of zebu-specific alleles in African cattle afforded a high resolution perspective on the hybrid nature of African cattle populations and also suggested that certain West African populations of valuable disease-tolerant taurine cattle are under threat of genetic absorption by migrating zebu herds.     

Epidemiology of bovine virus diarrhoea in cattle on communal alpine pastures in Switzerland

The goal of this study was to determine the influence of communal pasturing on the spread of bovine virus diarrhoea (BVD). The investigation involved 990 Swiss Braunvieh cattle from 149 different owners on seven communal pastures in the Swiss Alps. Prior to pasturing, blood samples were collected from all animals for examination for BVD antigen and antibodies. Serological examinations were also performed during and after pasturing to determine possible increases in seroprevalence and to determine whether seroprevalence was different on pastures with and without persistently infected cattle. At the start of pasturing, nine (0.9%) animals were persistently viraemic. On three alpine pastures, no persistently viraemic animals were detected. The prevalence of persistently infected cattle on the remaining four pastures varied from 0.3 to 3.9%. Of the 990 animals tested at the start of pasturing, 632 (63.3%) were seropositive. Seroprevalence differed among pastures and varied from 21.8 to 85.9%. During the summer, seroprevalence increased on all pastures surveyed, and at the end of the pasture season, 778 (80.1%) of the 971 cattle that were examined twice were seropositive. The incidence of seroconversion was significantly higher on pastures with persistently infected cattle compared with those without; it ranged from 32.7 to 100.0% in the former and from 6.0 to 22.2 in the latter. The results of this study suggest that communal alpine pasturing does play a role in the spread of BVD. The extent of this role depends on the presence of persistently infected animals.     

Use of a multifenestrated indwelling lavage system for treatment of septic digital tenosynovitis in cattle

Septic tenosynovitis was diagnosed in seven cattle on the basis of history, physical examination, radiographs, cytological examination of tendon sheath fluids, and microbial culture. A commercially available indwelling multifenestrated silicone rubber drain was used to perform frequent lavage of the flexor tendon sheaths. The sepsis resolved in all cattle. Five of six cattle for which long-term (> 1 year) follow-up information was available were clinically sound on the affected limb and had remained productive members of the herd.     

A long term epidemiological study of bovine viral diarrhoea infections in a large herd of dairy cattle

Epidemiological aspects of bovine viral diarrhoea virus (BVDV) infections were studied longitudinally in a large dairy herd for three years. At the start of the study, practically all the cows more than four years old had BVDV antibody titres, whereas the younger stock were almost all seronegative. The spread of the virus was monitored in a part of the population that contained only transiently viraemic cattle and in another part that contained persistently viraemic calves. Among the lactating cows the virus circulated for two-and-a-half years, although they had no direct contact with persistently viraemic cattle during this period. The highest transmission rate occurred when a large number of susceptible heifers was added to the population of cows that contained transiently viraemic cattle. The circulation of BVDV among the lactating cows ceased while 27 seronegative cows were still present. Both findings are in accordance with predictions from simple epidemic models. The susceptibility of the cows that remained seronegative was confirmed experimentally. In contrast with the limited circulation of BVDV caused by transiently viraemic cattle, virtually all susceptible cattle that came into contact with a persistently viraemic calf became seropositive within three months. Transplacental BVDV infections were not detected in the calves born to cows that had antibodies against the virus due to an infection that had occurred at least four years earlier. Transplacental transmission of BVDV did not occur in most of the pregnant cows that were infected before approximately the 60th day of gestation, but when cows became infected later in gestation the virus virtually always invaded the fetus.(ABSTRACT TRUNCATED AT 250 WORDS)     

Morphological study of the surface structure of the omasal laminae in cattle, sheep and goats

The mucosal relief of the omasum in cattle, sheep and goats was examined by the naked eye, stereoscopic microscope and scanning electron microscope. The mucosal relief of the omasum showed wide variations both between and within these species. Omasal papillae on the laminae varied highly in shape, i.e. conical, rounded, claw-like, wart-like, finger-like etc. They decreased gradually in size from the oral to the aboral region of the omasal lamina. Ridge-like structures and linear arrangements of the papillae were also seen on the omasal laminae of cattle and sheep. Many grooves and folds were found on the lateral surface of the omasal papillae in adult cattle and on the inter-papillar surface of the laminae of all three species. The mucosal relief of the omasum in cattle seemed to be more well-developed than those of sheep and goats. Dietary effects on the omasal mucosa were also discussed.     

Chronic Sarcocystis infections in slaughtered cattle

Parasitological, histopathological and immunohistochemical examinations were carried out on three slaughtered cattle with many nodules in all the striated muscles. At necropsy, many yellowish green rice-grain sized nodules including cheesy contents were observed in all the striated muscles. Histopathologically the nodules were granuloma principally consisting of eosinophiles. No Sarcocystis cysts nor bradyzoites were found in the nodules, but intact sarcocysts were found in the normal tissues surrounding the nodules. The central necrotic focus of nodules showed intense positive responses against anti-Sarcocystis cruzi rabbit serum by immunohistochemical examination. From the above findings the slaughtered cattle were diagnosed as chronic sarcocystiasis.     

Bronchiectasis in yearling feedlot cattle

Thoughout all of 1974, we surveyed, for illnesses and deaths, about 407,000 yearling feedlot cattle. From the 3,943 dead cattle, 1,988 necropsies were made; of the cattle necropsied, 32 (1.6%) had bronchiectasis. In this disease, the permanently dilated small bronchi and bronchioles, located in ventral parts of the lungs, were filled with accumulations of exudate and microorganisms, including Pasteurella hemolytica, Pasteurella multocida, Corynebacterium pyogenes, Escherichia coli, Salmonella anatum, Staphylococcus spp, and Mycoplasma arginini.     

Concurrent abomasal displacement and perforating ulceration in cattle: 21 cases (1985-1996)

OBJECTIVE: To evaluate the association of physical examination and clinicopathologic findings with surgical findings in cattle with concurrent abomasal displacement and perforating ulceration, to determine short- and long-term survival rates in these cattle, and to determine whether degree of peritonitis (focal vs diffuse) influences survival rates. DESIGN: Retrospective study. ANIMALS: 21 cattle with concurrent abomasal displacement and perforating ulceration and 42 cattle with uncomplicated abomasal displacement. PROCEDURE: Information on signalment, stage of lactation, physical examination findings, clinicopathologic data, surgical diagnosis, procedure(s) performed, and necropsy findings were retrieved from medical records of all cattle included in this study. Differences between physical examination findings of cattle with concurrent disease and those of cattle with uncomplicated displacements were evaluated, as were differences between survival rates in cattle with focal versus diffuse peritonitis. RESULTS: Cattle with concurrent disease had a greater probability of having pneumoperitoneum and signs of abdominal pain identified on physical examination than did cattle with uncomplicated diseases. There was no relationship between clinicopathologic data and survival time. Short-term survival rate was 38%, and degree of peritonitis significantly influenced survival time in cattle with concurrent abomasal displacement and perforating ulceration. Long-term survival rate in these cattle was 14%. CLINICAL IMPLICATIONS: Cattle with concurrent displaced abomasum and perforating ulceration have a poor chance for survival. In addition to detection of displaced abomasum, physical examination findings that can help lead to a presurgical diagnosis of this syndrome are pneumoperitoneum and signs of abdominal pain.     

Growth and carcass characteristics of cattle and buffalo breeds reared on a dry zone pasture in Sri Lanka (Ceylon)

Growth and carcass characteristics were measured on calves from three cattle breeds-the Sinhala, Red Sindhi and Friesian-and two buffalo breeds-the local buffalo and Murrah. The growth study was carried out on Brachiaria brizantha pasture over a period of 48 weeks. The two buffalo breeds grew fastest followed by the two Bos indicus breeds. The Friesian cattle grew at the slowest rate. The Sinhala and local buffalo had normal haematocrit values while the values for all other breeds were lower. The Sinhala and local buffalo had the highest carcass dressing percentages and the highest muscle; bone ratios. Tenderness measured by Warner-Bratzler shear force values and palatability scores by a taste panel were similar for meat from cattle and buffalo.     

A translocation t(8;14) and c-myc gene rearrangement associated with the histological transformation of B-cell acute lymphocytic leukemia (FAB-L2) into Burkitt''s type (FAB-L3) leukemia

During the late rainy season and winter season in 1990, outbreaks of suspected trypanosomiasis in native cattle (Bos indicus) occurred on 13 farms in Petchaboon province, Thailand. Forty-two cattle presented with nervous symptoms including circling, excitation, jumping, aggressive behavior, lateral recumbency, convulsion and finally death. Blood samples from 39 cattle on the two farms in which the outbreaks occurred were collected and examined for the presence of Trypanosoma evansi. It was found that all 16 blood samples from cattle on farm A were positive of T. evansi by mouse inoculation and indirect fluorescent antibody test (IFAT). In cattle from farm B, on the other hand only 37.5% and 39% of the samples were positive by mouse inoculation and IFAT, respectively. T. evansi was detected on impression smears of organs from the three cattle which died with nervous symptoms and also in smears made from their cerebrospinal fluid. In addition, trypanosomes were isolated from the cerebrum, cerebellum, pons and spinal cord by mouse inoculation.     

Isotype-specific antibody responses to foot-and-mouth disease virus in sera and secretions of "carrier' and "non-carrier' cattle

Isotype-specific antibody responses to foot-and-mouth disease virus (FMDV) were measured in the sera and upper respiratory tract secretions of vaccinated and susceptible cattle challenged with FMDV by direct contact or by intranasal inoculation. A comparison was made between cattle that eliminated FMDV and those that developed and maintained a persistent infection. Serological and mucosal antibody responses were detected in all animals after challenge. IgA and IgM were detected before the development of IgG1 and IgG2 responses. IgM was not detected in vaccinated cattle. Challenge with FMDV elicited a prolonged biphasic secretory antibody response in FMDV "carrier' animals only. The response was detected as FMDV-specific IgA in both mucosal secretions and serum samples, which gained statistical significance (P < 0.05) by 5 weeks after challenge. This observation could represent the basis of a test to differentiate vaccinated and/or recovered convalescent cattle from FMDV "carriers'.     

Studies of the prevalence of Coxiella burnetii, the agent of Q fever, in the foothills of the southern Bavarian Forest, Germany

In studies carried out in 1991 in the foothills of the southern part of the Bavarian Forest, in the district of Freyung/Grafenau, ticks and small mammals were collected and examined for the presence of Coxiella (C.) burnetii and sera of small mammals and cattle investigated for antibodies against this rickettsia. A total of 1716 imagines and nymphs of Ixodes ricinus were collected by flagging and 892 larvae and nymphs of the same tick species removed from small mammals. In addition to 1095 serum samples from cattle, 326 specimens of nine species of small terrestrian mammals were examined. Neither in ticks nor in rodents, C. burnetii was detected, however, in 17 of 21 localities, seropositive cattle were found. Altogether, 12% of all 1095 heads of cattle tested were seropositive for C. burnetii antibodies. These serological results indicated a wide dissemination of C. burnetii in cattle of the region investigated, but there was no indication of a natural focus. As in other areas of Europe, an independent natural cycle of the agent involving cattle only is assumed to occur in this region.     

I&R (identification and registration) system cattle: an analysis of its use during a foot-and-mouth-disease outbreak in The Netherlands

The performance of the Dutch cattle I&R system was analysed, with emphasis on the potential use of the system for the control of an outbreak of foot and mouth disease (FMD). The analysis showed that not all mutations were centrally registered within the three working days that are allowed to pass between the actual change and the obligatory report. In particular, young calves and cattle heading for slaughter were reported too late. During an outbreak of FMD, the best strategy to trace animals off a farm seems to be first to identify all animals on the farm, using a preprocessed list of the animals that should be present on the farm according to the I&R system. Then all the animals that have left the farm during the last month can be traced in the central I&R computer or by asking the person to whom the farmer sold the cattle (the next owner). In the present study, 54% of the animals were localized within one day, and 94% within one week. Finally, some suggestions for improvement for the system are given.     

Vascular arrangement in the skin of tropical cattle

The vascular arrangement in the skin of some tropical breeds of cattle and of temperate cattle in a tropical environment is reported. Four vascular plexuses were observed in the skin of all breeds of cattle studied. The first horizontal plexus was observed between the subcutaneous and reticular layers, the second at mid-reticular layer level, and the third and most prominent at the level of the hair papillae and sweat glands. The fourth plexus arose as a branch from the third, extended upwards to the sebaceous gland and upper hair follicle region and gave off twigs to the dermo-epidermal junction. The sweat glands and hair follicles were profusely supplied with blood vessels. The branches of the fourth plexus extended closer to the epidermis in the tropical breeds than in the Friesian.     

Salmonella typhimurium DT104 infection in people and animals in Scotland: a collaborative epidemiological study 1993-96

This paper describes a comparative analysis of human and farm animal salmonellosis in Scotland between 1993 and 1996, with particular reference to Salmonella typhimurium definitive type 104 (DT104). Cattle were the main reservoir, accounting for 73.1 per cent of incidents involving all salmonellae and 69.5 per cent of those involving S typhimurium DT104. The annual rates of incidence in people and cattle were recorded in each Health Board area. Dumfries and Galloway had the highest rate of incidence in cattle for all salmonellae (19.0 per 100,000) but people were affected uniformly across mainland Scotland. However, the rate of incidence of S typhimurium DT104 was highest in Dumfries and Galloway for both people (10.1 per 100,000) and cattle (13.0 per 100,000). In Dumfries and Galloway, Wigtownshire had the highest rates for all salmonellae and for S typhimurium DT104 in both people and cattle. In Dumfries and Galloway, 37.8 per cent of the adult cases of S typhimurium DT104 in people were among those known to have had regular contact with animals, and children under six years of age accounted for 36.3 per cent of the human infections in this region.     

Assessment using ELISA of the herd immunity levels induced in cattle by foot-and-mouth disease oil vaccines

The development of a liquid-phase blocking sandwich ELISA (LPBE) to measure antibodies (Ab) produced in cattle with the O, A and C foot-and-mouth disease virus (FMDV) types of commercial vaccines used in Argentina is described. The test was specific: 99% of na?ve cattle sera (n = 130) gave titres below log10 = 1.2, and none had a titre above log10 = 1.5. Comparative studies with serum neutralization test (SNT) using sera from cattle which received one or more vaccine doses is reported. The overall rank correlation coefficient (Spearman's rho, rs) between SNT and LPBE were highly significant (rs > 0.67, P < 0.0001) for all vaccine strains. LBPE Ab titres on sera collected 90 days post vaccination were compared with results of cattle protection tests by applying a logistic regression. The minimum Ab titres at which 85% and 75% of the cattle were protected for each FMDV type were determined in order to interpret field Ab data in terms of protection. Application of this method allows large scale serological examinations to monitor antibody levels in vaccinated animals as an indirect indicator of the FMD control program status in the field. Its use in the evaluation of commercial batches of FMD vaccine is discussed.