Search Results

Abstract

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.

Procedure—Milk samples, antemortem swab specimens from various body sites, and postmortem swab and tissue specimens were submitted for Mycoplasma culture. Pulsed-field gel electrophoresis (PFGE) was performed on chromosomal digests of all Mycoplasma isolates. Isolates with the same number and size of chromosomal digest bands were considered to be of the same type.

Results—For each cow, all isolates obtained from milk, mammary gland parenchyma, and supramammary lymph nodes had the same PFGE pattern. All cows had at least 1 isolate from nonmammary system tissues that had the same PFGE pattern as isolates from the mammary system. Overall, 44 of the 70 (63%) Mycoplasma isolates obtained from body sites other than mammary system sites had the same PFGE pattern as did mammary system isolates.

Conclusions and Clinical Relevance—Results confirmed our hypothesis that Mycoplasma strains isolated from the milk of dairy cattle with Mycoplasma mastitis frequently have PFGE patterns identical to those for strains isolated from other body sites, suggesting that there is at least a potential for internal transmission of Mycoplasma organisms. (J Am Vet Med Assoc 2005;227:455–459)

Abstract

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.

Procedure—Dried lupine (2 g/kg) was administered via gavage. Blood samples were collected before and at various time points for 48 hours after lupine administration. Anagyrine, 5,6-dehydrolupanine, and lupanine concentrations in plasma were measured by use of gas chromatography. Plasma alkaloid concentration versus time curves were generated for each alkaloid, and pharmacokinetic parameters were determined for each cow.

Results—No significant differences in area under the plasma concentration versus time curve, maximum plasma concentration, time to reach maximum plasma concentration, and mean residence time for the 3 alkaloids were found between groups.

Conclusions and Clinical Relevance—Because no differences were found in plasma disposition of anagyrine following lupine challenge between cattle that had given birth to calves with arthrogryposis and those that had not, our findings do not support the hypothesis that between-cow differences in plasma disposition of anagyrine account for within-herd differences in risk for lupine-induced arthrogryposis. (Am J Vet Res 2004;65:1580–1583)