Formula omitted][formula omitted]—Induced abortion

Abstract

History and Clinical Signs : Cattle herds infected with Vibrio fetus venerealis have histories of infertility and occasional abortions. V. fetus intestinalis does not cause infertility but dose cause sporadic abortion in cattle. Gross Lesions : Fetal tissues are usually not autolysed and the lungs are often partially expanded. Slight dehydration of the carcass, fibrinous pericarditis, pleuritis or peritonitis, or intraabdominal hemorrhage resulting from a ruptured liver may be present. Placentitis is a constant though not pathognomonic lesion. Microscopic Lesions : Suppurative, necrotic placentitis is a constant though not pathognomonic lesion. Suppurative bronchopneumonia or interstitial hepatitis or both may be present. Cultural Procedures : V. fetus can be isolated most consistently from the fetal abomasal contents and placenta. It may also be isolated from the fetal tissues. Serologic Procedures : Protocols have been described for examining blood and vaginal mucus from cows for antibodies to V. fetus . Neither of these tests is considered sufficiently accurate for diagnosing vibriosis in individuals. Special Procedures : Examination of wet mounts of fetal abomasal contents with dark field or phase contrast microscopy often reveals the presence of V. fetus . The organisms are recognizable by their morphology and characteristic rapid, darting, corkscrew means of motility. V. fetus may be detected in fetal and placental tissues and abomasal contents by fluorescent antibody (FA) techniques. Difficulty has been encountered in producing FA conjugates with sufficient specificity and adequate controls should always be used. Preferred Diagnostic Methods : 1. 1. Cultural isolation of V. fetus from the fetal or placental tissues or abomasal contents. Identification of the organism by physical and biochemical characteristics. 2. 2. Observation by dark field or phase contrast microscopy of abomasal contents of organisms with the characteristic motility and morphologic features of vibrio. 3. 3. Demonstration of vibrio organisms in fetal or placental tissues or abomasal contents by properly applied and controlled F.A. techniques. 4. 4. Determination of agglutinating antibodies in the serum of cows which have aborted (within one month following abortion).