Field disease investigation-A differentiating and integrative approach to problems in animal populations.

The economically important diseases of agricultural animals are those that affect groups of animals to result in impaired productivity or mortality. Herd and flock disease result from complex interactions between inciting agents (or other etiologies), and factors such as management systems, nutrition, environment and other contributory causes. For these reasons herd and flock disease problems must be addressed, researched, and taught, in the areas where they occur-on the farm and in the field.

Lupine induced "crooked calf disease" in Washington and Oregon: identification of the alkaloid profiles in Lupinus sulfureus, Lupinus leucophyllus, and Lupinus sericeus.

Several lupines (Lupinus spp.) present on western U.S.

Genetic diversity of Listeria monocytogenes strains from a high-prevalence dairy farm.

Listeria monocytogenes is a significant food-borne human and veterinary pathogen. Contaminated silage commonly leads to disease in livestock, but the pervasive nature of the bacterium can make it difficult to identify the source of infection. An investigation of bovine listeriosis that occurred on a Pacific Northwest dairy farm ("farm A") revealed that the clinical strain was closely related to fecal strains from asymptomatic cows, and that farm environment was heavily contaminated with a diversity of L.

Pulsed-field gel electrophoresis patterns of Mycoplasma isolates from various body sites in dairy cattle with Mycoplasma mastitis.

Objective: To determine whether Mycoplasma strains typically associated with mastitis in dairy cattle can be isolated from body sites other than the mammary gland.

Design: Prospective clinical trial.

Animals: 7 Holstein cows in various stages of lactation with intramammary Mycoplasma infection.

Comparison of plasma disposition of alkaloids after lupine challenge in cattle that had given birth to calves with lupine-induced arthrogryposis or clinically normal calves.

Objective: To compare plasma disposition of alkaloids after lupine challenge in cattle that had given birth to calves with lupine-induced arthrogryposis and cattle that had given birth to clinically normal calves and determine whether the difference in outcome was associated with differences in plasma disposition of anagyrine.

Animals: 6 cows that had given birth to calves with arthrogryposis and 6 cows that had given birth to clinically normal calves after being similarly exposed to lupine during pregnancy.

Procedures: Dried lupine (2 g/kg) was administered via gavage.

Dairy farm reservoir of Listeria monocytogenes sporadic and epidemic strains.

Identifying the reservoirs of a pathogen is vital for control of sporadic disease and epidemics. Listeria monocytogenes is a zoonotic foodborne pathogen that is responsible for 28% of food-related deaths in the United States annually, as well as a major cause of massive product recalls worldwide. To examine the role of the dairy farm as a potential source or reservoir for L.