title: A survey of causes of bovine abortion occurring in the San Joaquin Valley, California.
abstract: The causes of abortion in cattle in the San Joaquin Valley of California were surveyed from submissions to the California Veterinary Diagnostic Laboratory at Tulare. Four hundred sixty-eight abortion cases were examined. Most submissions (89%) were from large drylot dairies, milking an average of 814 cows. Abortion evaluations included necropsy, histopathology, bacteriology, virology, and other immunologic and serologic tests. A specific cause was identified in 29.5% of the abortions. Bacterial infections, most of which were sporadic, accounted for 16% of all abortions. Viral causes and protozoal infections were diagnosed in 5.6% and 3.2% of the abortions, respectively. Fetuses with protozoal infection had histologic lesions of focal nonsuppurative necrotizing encephalitis, and protozoa were detected. Similar histologic lesions were seen in 80 additional fetuses (17.1%), and although an etiologic agent was not identified for these cases, a protozoal infection was suspected.
authors.affiliation: California Veterinary Diagnostic Laboratory, Tulare Branch, CA 93274.
authors.forename: M L
authors.initials: ML
authors.lastname: Anderson
authors.forename: P C
authors.initials: PC
authors.lastname: Blanchard
authors.forename: B C
authors.initials: BC
authors.lastname: Barr
authors.forename: R L
authors.initials: RL
authors.lastname: Hoffman
mesh_terms: D000034:Abortion, Veterinary / Q000209:etiology* / Q000382:microbiology / Q000469:parasitology; D000818:Animals; D001424:Bacterial Infections / Q000150:complications / Q000662:veterinary*; D002140:California; D002417:Cattle; D002418:Cattle Diseases / Q000209:etiology* / Q000382:microbiology / Q000469:parasitology; D005260:Female; D009566:Nitrates / Q000506:poisoning; D011041:Poisoning / Q000150:complications / Q000662:veterinary; D011247:Pregnancy; D011528:Protozoan Infections / Q000150:complications; D011529:Protozoan Infections, Animal; D012189:Retrospective Studies; D014777:Virus Diseases / Q000150:complications / Q000662:veterinary*
chemical_list: D009566:Nitrates