ANOXIA IN THE BOVINE FOETUS

SUMMARY Laparohysterotomies were performed, under local analgesia, on 18 plurigravid Hereford cattle and the response of their foetuses to anoxia was examined. All control and 4 of 6 foetuses subjected to 4 minutes of anoxia survived whereas all others died when the umbilical cord was clamped for 6 or 8 minutes. Death mostly occurred just before or soon after delivery, which was undertaken immediately following release of the umbilical clamp. In 2 cases, however, the calves survived for at least 2 days before being slaughtered when death appeared imminent. During the intervening period both animals failed to suck although one was able to stand temporarily following the oral administration of glucose and milk.     

MYELOGRAPHY IN NEONATAL BOVINE CALVES

This study was undertaken to establish a protocol for myelography in the neonatal bovine calf. Five normal calves, one to five days old, were examined radiographically by myelography, using techniques recommended for the equine and canine. The contrast medium used was lopamidol, which was introduced through the foramen magnum under general anesthesia. When the protocol was established, several neonatal calves with partial or complete pareses were examined myelographically. Myelography revealed changes in the spinal canal and assisted in a definite diagnosis. No harmful effects were observed in the normal or abnormal calves during or after myelography. It was concluded that myelography is a valuable safe procedure for diagnosis of causes of paresis in neonatal calves.     

BOVINE MELIOIDOSIS IN SOUTH-EASTERN QUEENSLAND

Acute fatal infection with Pseudomonas pseudomallei caused pneumonia, placentitis and endometritis in a pregnant cow. Pneumonia was also present in the foetal lung. Mononuclear cell response with extensive karyorrhexis occurred in maternal and foetal lung and the same cellular pathology, but with diffuse distribution, was responsible for plaques on the endometrium. A more chronic disease with encapsulated caseous lesions in the lung, together with arthritis, occurred in a bull on the same property. Nutritional and physical stress caused by a flood were thought to be predisposing factors. An unusually wet summer with prolonged flooding apparently provided suitable environmental conditions for saprophytic growth of Ps. pseudomallei in an area far south of the region in which infection of animals with this organism commonly occur.     

BOVINE ENZOOTIC HAEMATURIA IN QUEENSLAND

Bovine enzootic haematuria was diagnosed in Queensland in coastal areas in association with bracken fern (Pteridium esculentum) on 3 properties or with mulga fern or rock fern (Cheilanthes sieberi) on 4 properties, and in inland areas in association with C. sieberi on 3 properties. In the absence of bracken fern, long-term ingestion of C. sieberi is suggested as a cause of bovine enzootic haematuria. Haemangiomas, haemangiosarcomas, transitional cell carcinomas, papillomas, fibromas and an adenoma were detected in the urinary bladders of 19 affected cattle and were accompanied by chronic cystitis.     

SEROLOGICAL RESPONSES IN EXPERIMENTAL BOVINE TUBERCULOSIS

Five two-year-old heifers were each inoculated intravenously with 0.02 mg M. bovis strain AN5. Clinical, haematological and microbiological observations were made during the course of the experiment and antibody levels were measured before and after infection by means of the indirect immunofluorescent antibody (IFA) and bentonite flocculation tests. All cattle developed M. bovis infection varying in severity from peracute tuberculous pneumonia resulting in death within 33 days to chronic progressive generalised tuberculosis. Only cattle developing peracute or acute forms of tuberculosis showed marked haematological changes characterised by leucopenia with lymphopenia. Bacteraemia was detected in the two cattle with peracute tuberculosis 22 days after infection. Anti-mycobacterial antibody was detected after infection in all cattle but fluctuated markedly during the course of the disease. Of a total of 61 serum samples examined from all cattle after inoculation with M. bovis, only 38 were positive to the IFA test and 30 to the bentonite flocculation test. Only 18 were positive to both tests at any one time. IgM was the predominant type of anti-mycobacterial antibody detected by the IFA test and this was found to cross-react with M. avium in almost every sample.