Bovine abortion associated with Anaplasma marginale.

During the period from June 1974 to June 1975, five bovine fetuses between seven to nine months old were received for necropsy from four different counties of the S. Paulo State, Brazil. All of them were from brucellosis-free herds. Necropsy revealed slight liver enlargement generally accompanied by capsular petechial hemorrhages. Enlargement and congestion of the spleen, epicardial and endocardial petechiae were present in three fetuses and one of them had lungs with some hemorrhagic lobules. Cardiac blood films of all the fetuses stained by the Pappenheim's panoptic method showed Anaplasma marginale in two to 20% of red corpuscles. When stained with acridine orange and immunofluorescent methods blood films of the first fetus specifically showed A. marginale.     

Epithelial intracytoplasmic herpes viral inclusions associated with an outbreak of duck virus enteritis.

Several muscovy ducks from a free-roaming flock of 65 muscovy and mallard ducks died over a 3-week period. Three muscovy ducks were necropsied. Gross and microscopic changes were compatible with duck virus enteritis, and the virus was isolated. In addition to intranuclear viral inclusion bodies in several tissues, intracytoplasmic inclusion bodies were present in esophageal and cloacal epithelium. By electron microscopy, the membrane-bound intracytoplasmic inclusions were found to contain enveloped herpesvirus, and nuclei contained herpes viral nucleocapsids.     

Botulism associated with feeding alfalfa hay to horses

Botulism was believed to be the cause of progressive symmetric myasthenia in 8 horses on a farm in North Carolina. One horse was found dead, 6 were euthanatized after becoming recumbent, and 1 affected horse recovered. Cecal and colonic contents of 2 horses were determined to contain Clostridium botulinum spores. Alfalfa hay that was fed to the horses contained spores and toxin.     

Bovine respiratory syncytial virus in Quebec: antibody prevalence and disease outbreak.

The prevalence of antibody to bovine respiratory syncytial virus in Quebec and the role of the virus in a respiratory disease outbreak was investigated. The indirect immunofluorescent, neutralization and haemagglutination inhibition techniques were used to carry out this study. Of the 1,444 adult animals examined 519 (35.9%) had antibody to bovine respiratory syncytial virus. These positive reactors were found in each agricultural region of Quebec. The highest (53.0%) and the lowest (21.8%) prevalence was observed in the sera collected by the laboratories of St. Hyacinthe and Sherbrooke. During a respiratory disease outbreak affecting 77 calves on a farm, bovine respiratory syncytial virus was shown to be associated with infectious bovine rhinotracheitis, bovine parainfluenza type 3, bovine viral diarrhea viruses and bovine adenovirus type 3 as detected by seroconversion. Of the 38 seroconverted animals 14 were seropositive to bovine respiratory syncytial virus.     

Bovine abortions associated with Bacteroides fragilis fetal infection.

Two Santa Gertrudis cattle from a herd of 105 aborted within a 24-hour period. Bacteroides fragilis was isolated from tissues of each aborted fetus. Histopathologic lesions included placentitis and bronchopneumonia in which gram-negative, rod-shaped organisms were visible. The diagnostic workup failed to reveal other causes of abortion. Anaerobes are rarely implicated in bovine abortions, and no other report was found that described abortion in cattle due to B. fragilis.     

Bovine diarrhea associated with Campylobacter hyointestinalis

An enteric disease affected 16 ruminating calves. The disease was characterized by a nonspecific, mild to severe diarrhea and wasting. Two calves died during the course of disease. C. hyointestinalis was isolated from 12 to 14 calves. The antibody titers of affected calves to C. hyointestinalis varied from 1:20 to 1:160. The disease was successfully treated with chloramphenicol.     

A mild outbreak of bovine mastitis associated with Mycoplasma bovigenitalium.

Mycoplasma bovigenitalium was isolated from milk samples from 16 of 99 cows on one farm during a 15-week period in the summer of 1986. One cow was severely affected, four cows had relatively mild signs of mastitis, and three had only altered dry-cow udder secretions. Eleven of the infected cows were dry and three had been calved less than 48 hours. The abrupt method of drying-off and improvements in cleaning of the milking equipment were introduced, but no other control measures were instituted to eradicate the mycoplasma infections. After this mild outbreak of mastitis the herd was monitored for the next 17 months. In total 19 cows had a mycoplasma isolated from udder secretions. Acholeplasmas were isolated from 14 cows but were not associated with clinical mastitis. The udder infections with mycoplasmas apparently resolved without resorting to the segregation and culling of infected animals.     

Datura contamination of hay as the suspected cause of an extensive outbreak of impaction colic in horses

Datura poisoning of horses is extensively reviewed. An outbreak of intractable impaction colic affecting 18 of 83 horses was stopped by withdrawing dried tef hay contaminated with young Datura plants. The dried, botanically identified Datura stramonium and D. ferox contained respectively 0.15% mass/mass (m/m) hyoscyamine as well as 0.16% m/m hyoscine (scopolamine) and only hyoscine at a concentration of 0.11% m/m. Immature, unidentifiable plants resembling D. stramonium, contained 0.14% m/m and 0.12% m/m of the 2 respective tropane alkaloids. The outbreak was characterised by protracted and repeated colic attacks due to impaction of the large colon and/or caecum without any other anti-muscarinic signs. Comparative analyses of single specimens of dried seed of the 2 species collected from both fertilised and waste areas revealed that young South African Datura spp. had levels of tropane alkaloids comparable to those in the well-known toxic seed and were, consequently, equally toxic. The inherent danger of tef hay being contaminated with Datura is emphasised. To our knowledge this is the 1st field case of poisoning in horses ascribed to the vegetative parts of Datura spp.     

Bovine cryptosporidiosis in Denmark. 2. Cryptosporidia associated with neonatal calf diarrhea

In recent years cryptosporidia have often been identified in diarrheic calves of under one month old, either as the sole pathogenic agent or in combination with other diarrhea-causing infectious agents. In 203 cases of bovine cryptosporidiosis, recorded over a period of two years, cryptosporidia were present in such great numbers that they would seem to be of causal significance. The calves were from three days to five weeks old. In 111 cases (55%) a monoinfection with cryptosporidia occurred, while in the rest of the cases mixed infections with other agents associated with calf diarrhea were demonstrated, especially rotavirus (61 cases) and coronavirus (32 cases); in addition, mixed infections with ETEC (four cases), septicaemic E. coli (two cases), salmonellosis (11 cases), and BVD and coccidiosis (one case each) were seen. In 87 (10%) of 849 4-21-day-old dead calves a massive occurrence of cryptosporidia was demonstrated. Extreme emaciation was noted in 36 of 122 autopsied calves. Most of these calves were more than 14 days old, and mono-infection with cryptosporidia was demonstrated in two thirds of them. In younger calves, more acute cases of cryptosporidiosis were commoner, often in connection with concomitant infections with rota- or coronavirus.     

Encephalitis in aborted bovine fetuses associated with Bovine herpesvirus 1 infection.

Brain tissue from 12 aborted bovine fetuses submitted to the Wisconsin Veterinary Diagnostic Laboratory revealed histologic lesions that consisted of glial nodules and variable degrees of mononuclear inflammation, microhemorrhage, neuronal necrosis, and cerebral cortical cavitation. A diagnosis of Bovine herpesvirus 1 (BHV-1) abortion had been made in all of these cases through multiple testing modalities. Brain tissue from 8 of the 12 fetuses was immunohistochemically stained with a monoclonal antibody specific to BHV-1, and, in 5 fetuses, there was positive intralesional staining of neurons, glial cells, and endothelial cells. This preliminary data suggested that herpesviral infection of brain tissue led to the described neurologic lesions. BHV-1 was then amplified from brain tissue in all 12 of the fetuses and was confirmed by partial sequencing of the thymidine kinase and glycoprotein C genes. To the authors' knowledge, neurologic lesions have not previously been described in BHV-1-infected fetuses, nor has BHV-1 previously been identified in bovine fetal brain tissue. The neurologic histopathology attributed to BHV-1 infection in these cases overlaps with the neurologic lesions produced by Neospora caninum, a common etiologic agent of bovine abortion. Therefore, when bovine fetal neurologic lesions are found, both etiologies should be considered and then distinguished by using additional diagnostic tools.