Severe thrombocytopenia in young calves experimentally infected with noncytopathic bovine viral diarrhea virus.

Seven calves between 1 week and 2 months of age were infected with a noncytopathic field isolate of bovine viral diarrhea virus (BDV) in order to evaluate the effect of BDV infection on the concentration of circulating platelets in the blood. All calves were determined to be free of BDV and neutralizing antibodies to BDV before infection. Platelet counts were performed on a daily basis over a 30-day period beginning at the time of infection. By 2 weeks postinfection, all calves showed a significant drop in the number of circulating platelets and a marked hyperplasia of megakaryocytes in the bone marrow. In three of the seven calves, thrombocytopenia was severe (less than or equal to 5,000/microliters) for 1 to 6 days. In two of these three animals, extensive petechial and ecchymotic hemorrhages were observed on all mucosal surfaces and on various internal organs during the period of severe thrombocytopenia. BDV was consistently isolated from the platelets during the early phases of the infection, and viral antigen was occasionally detected on platelets by a fluorescent-antibody assay. The results demonstrate that BDV infection is associated with decreases in platelet numbers and suggest that platelets may serve as carriers of circulating virus.

Bovine virus diarrhoea virus, a cause of early pregnancy failure in the cow.

In the present report attention is drawn to clinical and hormonal changes in heifers following experimental or natural infection with bovine virus diarrhoea virus in early pregnancy. Three heifers were infected experimentally and one naturally at pregnancy stages from 29-41 days. A leukopenia was seen 5-7 days after infection. All four animals experienced foetal death. Two of them aborted and in two the foetus was resorbed. Oestrus was observed at the expulsion of the foetus or in connection with vaginal discharge. Peripheral blood plasma levels of progesterone and the main blood plasma metabolite of prostaglandin F2 alpha (15-keto-13,14-dihydro-PGF2 alpha) were analysed. Diagnosis of pregnancy and embryonic/foetal viability were monitored by ultrasound. The interrelationship between infection and reproductive endocrinology is discussed and the importance of avoiding infection in early gestation is pointed out. It may easily pass unobserved and can thereby cause serious economic loss.

Thrombocytopenia associated with acute bovine virus diarrhea infection in cattle.

Thrombocytopenia was observed in 15 of 146 cases of clinically acute bovine viral diarrhea virus (BVDV) infection in adult cattle. Platelet counts ranged from 2,000 to 33,000/microliters. Clinically, a bleeding tendency was manifested by bloody diarrhea, petechial and ecchymotic hemorrhage, epistaxis, and abnormal bleeding from injection sites. Coagulation testing (six cases) gave no evidence of disseminated intravascular coagulation. Bone marrow aspirates were suggestive of active marrow necrosis (two cases) or recent repopulation (three cases). Treatment, when given, was supportive and empirical in nature. Six animals experienced complete clinical recoveries; the others died or were euthanatized. Although the pathogenesis of the thrombocytopenia was not definitively determined, thrombocytopenia associated with acute BVDV infection should be considered in the differential diagnosis for cattle with bleeding disorders.

Severe respiratory disease in dairy cattle in New York State associated with bovine respiratory syncytial virus infection.

Severe respiratory disease associated with bovine respiratory syncytial virus (BRSV) infection has been identified in dairy cattle in New York State. The cases identified occurred in dairy calves and heifers. The disease was characterized in 4 animals by pathologic changes including interstitial pneumonia, necrotizing bronchiolitis with multinucleated syncytial epithelial cells and interstitial emphysema. BRSV antigen was demonstrated in lung samples or was isolated in tissue culture in all 4 cases. A retrospective survey of 6279 bovine diagnostic accessions between 1977 and 1982 revealed 66 cases of interstitial pneumonia, often with concurrent bronchiolitis. In this 5 year period, only 1 case in 1981 had interstitial pneumonia and bronchiolitis with pathologic features consistent with BRSV infection. It is concluded that pathogenic BRSV has entered New York State and that it is contributing to clinical respiratory disease in dairy cattle.

Left displacement of the abomasum: relationship to age and medical history.

The present study shows that 5 years is the numerically most frequently observed age at onset of left displacement of the abomasum (LDA) in dairy cows, and that the risk of LDA actually increases with age (Fig. 1 and 2). A high prevalence (70-75%) of other or concurrent disorders among LDA cows is observed (Tables I and II). The apparent excess risk among LDA cows of getting other diseases throughout their lives, including retained placenta (RP), disappeared when adjustments were made for age (Tables III and IV) and it is concluded that LDA cows have a higher incidence of other disorders mainly because they tend to be older cows. A negative influence of RP and LDA on reproductive performance was finally observed (Table V).

Effects of caesarean section, retained placenta and vaginal or uterine prolapse on subsequent fertility in beef cattle.

Data collected at the Livestock and Range Research Station, Miles City, Montana, on 13,296 calving from the years 1963 through 1977 were used to evaluate subsequent reproductive performance of dams experiencing caesarean section, retained placenta or vaginal or uterine prolapse. A total of 121 caesarean sections (.9% of all calvings) was performed from 1963 through 1977, with the highest incidence reported among first-calf 2- and 3-year-old dams. Fall pregnancy rate among the 105 dams that had caesarean deliveries was 52.4%, which was 26.6% lower (p less than .01) than the herd average. Fetal membranes were retained after 49 natural parturitions. Pregnancy rates among dams retaining fetal membranes were not significantly altered (82.2 vs 79.4%). A total of 153 calvings was associated with prolapse of the reproductive tract, including 124 (81.0%) vaginal prolapses and 29 (19.0%) uterine prolapses. Subsequent pregnancy rate of all dams experiencing prolapse was lower (p less than .01) than the herd average. Pregnancy rates following prolapse among primiparous and multiparous dams were 28.0 and 57.9%, respectively. These data indicate that caesarean section and vaginal or uterine prolapse result in significant reductions in subsequent pregnancy rates of affected dams, with no detrimental effect on dams retaining fetal membranes.

[Diaphragmatic hernia as a rare complication during caesarean section in a cow (author's transl)]. / Hernia diafragmatica als zeldzame complicatie tijdens een sectio caesarea bij een rund.

The literature on diaphragmatic hernia in cattle and buffaloes is reviewed. A heifer showed accelerated respiration, symptoms of dyspnoea, occasional coughing and groaning, a variable appetite and emaciation unaccompanied by an increase in temperature for sixteen days prior to parturition. A diagnosis was not established. During parturition which occurred at term, marked symptoms were not observed, and it was decided to perform caesarian section because of the unduly large foetus. During the operation, performed in the standing animal, the heifer offered violent resistance when the abdominal cavity had been opened, showing symptoms of severe dyspnoea and/or pain, an fell down. In this state of excitement, which subsequently came to resemble shock, the heifer showed cyanotic mucosae and a very quick pulse. The heart sounds on the left side were inaudible on auscultation. The operation could only be completed in the recumbent position after sedation. Nothing which could account for the symptoms was detectable throughout treatment. The animal then remained quiet, the mucosae having regained their pink colour, the pulse rate decreased. Respiration continued to be too rapid and it became plain that it was obviously of the pendular type. The animal having been slaughtered in agreement with the owner, diaphragmatic hernia was found to be present on the left side. The enlarged spleen was largely situated in the thorax and partly adhered to the lung. The history of the case is discussed.

[Mucosal disease virus as a cause of enzootic abortion in cattle in Czechoslovakia]. / Virus sliznicní choroby jako prícina enzootických abortu v chovech skotu v CSSR.

Bovine viral diarrhoea -- mucosal disease (BVD-MD) virus was demonstrated on some farms as the causal agent of enzootic abortions in cattle. On the whole, five non-cytopathogenic strains of the BVD-MD virus were isolated from the organs of aborted foetuses of different age and prematurely born calves. The strains were identified by the direct immunofluorescence method. The same method was also used in detecting the virus antigen in the organs and tissues of colostrum deprived prematurely born calves and also calves born at term. The involvement of the BVD-MD virus in the abortions was demonstrated indirectly by detecting virus-neutralizing antibodies in the serum of heifers and cows, in the pre-colostral sera of newly born calves, and in the body fluids of aborted foetuses. The discussion deals with the importance of the BVD-MD virus as a cause of enzootic abortions, foetal malformations and early postnatal mortality of calves.

[Cows which are unable to stand (author's transl)]. / De koe die niet kan staan.

The most important features of the previous history and on examination, to which attention should be paid to ensure a correct diagnosis and prognosis in syndromes in which inability to stand is an outstanding symptom, are described.

Bovine granular vulvitis associated with ureaplasma infection.

A granular vulvitis syndrome associated with ureaplasma infection was first recognized in Ontario dairy herds in 1972. The acute form of the disease was characterized by a purulent vulvar discharge, an inflamed hyperemic vulvar mucosa and varying degrees of granularity. In the chronic form, there was an absence of a purulent discharge and a gradual decline in the severity of the hyperemia and granularity. Epithelial inclusion cysts were observed in the vulvar epithelium of approximately 10% of affected cows.A seasonal variation in the incidence of the disease was observed. Herd morbidities during the summer months reached a low of 37% and increased to 75% during the winter months with constant housing.When widespread in herds, the acute form of the disease had a significant effect on fertility. In four herds examined, first service conceptions dropped on average by 27%. The chronic form of the disease had a less detrimental effect on fertility with first service conceptions being reduced on average by 13%. Intrauterine infusions of a tetracycline 24 hours postbreeding were found to be of value in improving conception rates in acutely affected herds.

[Effect of hypodermyiasis in cattle on milk-production indicators in 1st-calvers]. / Vliv hypodermatózy skotu na produkcní ukazatele mléka u prvotelek.

We investigated the effect of hypodermosis on the quantitative and some qualitative indicators of milk from 20 experimental and 18 control first-calvers of the Pinzgau cattle breed. The experiment took place at two experimental localities in mountainous pastures of the Central-Slovakian region. In the experimental animals, treated with Hypocid, the production of milk per dairy cow increased on an average by 115.98 kg, i.e. 24.83%, over the experimental period of 61 days (May, June) with an average invasion intensity of 5.94 larvas in control animals. Milk fat production increased on an average by 7.20 kg, i.e. 34.97%. Production recalculated to FCM milk amounted on an average to 31.61%. The profitability of treating hypodermosis with the Hypocid preparation is expressed by the average savings of 0.40 Kcs per litre of milk per day.