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  • Author or Editor: Brent B. Parker x
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To evaluate the sensitivity and specificity of 2 commercial test kits for detection of occult blood in canine feces, various volumes of blood were administered to 6 dogs via orogastric tube. Blood volumes tested were chosen on the basis of hemoglobin quantities of 5, 10, 20, 200, 350, and 500 mg of hemoglobin/kg of body weight. Fecal specimens were collected twice daily and analyzed separately by 2 observers for the presence of occult blood by use of modified guaiac and orthotolodine tablet tests, and for melena by visual inspection. Five dogs given blood at the rate of 500 mg of hemoglobin/kg and 1 dog given blood at the rate of 350 mg of hemoglobin/kg developed melena. Results of both occult blood tests were positive in 2 of 6 dogs given blood at the rate of 5 mg of hemoglobin/kg. Five of 6, and 4 of 6 dogs given blood at the rate of 10 mg hemoglobin/kg had positive test results by modified guaiac and orthotolodine methods, respectively. Results of both methods were positive in all dogs given blood at the rate of 20 mg of hemoglobin/kg. There was 86% agreement between the 2 observers’ results for the modified guaiac method, and 78% agreement for the orthotolodine method. There was 77% agreement of results between the 2 test methods. Gastrointestinal transit time decreased with increasing volumes of blood. Occult blood testing was found to be useful for detection of blood in feces at volumes 20 to 50 times less than that required to cause melena.

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in American Journal of Veterinary Research


Objective—To determine the effect of transportation stress on serum concentrations of oxidative stress biomarkers of calves.

Animals—105 crossbred beef steer calves (mean [± SD] body weight, 207 ± 21.2 kg).

Procedure—Calves were assembled at 1 location in Tennessee, and pretransit (day –3) blood samples were collected. Calves were allotted randomly by body weight into 2 groups. Calves were transported 1,930 miles to a feedlot in Texas, and 1 group received tilmicosin phosphate (33 µg/kg, SC) upon arrival. Calves were weighed and blood samples collected on the day of arrival (day 1) and on days 15, 22, and 28. Calves were scored daily for signs of bovine respiratory disease (BRD). Serum total antioxidant capacity (TACA) and serum malondialdehyde (MDA) concentrations were determined.

Results—Transportation stress significantly decreased mean serum TACA concentrations (from 147 ± 31.2 U/mL to 133 ± 20.1 U/mL) and significantly increased serum MDA concentrations (from 10.9 ± 18.3 µg/mL to 30.2 ± 50.5 µg/mL). Calves that died had a 43% increase in serum MDA concentration on day 1, compared with calves that lived (42.2 ± 67.0 µg/mL vs 29.4 ± 49.4 µg/mL, respectively). Calves that had ≥ 3 episodes of BRD had 2-fold higher serum MDA concentrations on day 1 than healthy calves. Tilmicosintreated calves had a 20.8% significantly greater average daily gain and significantly greater serum TACA concentration than nontreated calves on day 28.

Conclusions and Clinical Relevance—Transportation stress increases serum concentrations of oxidative stress biomarkers that are related to episodes of BRD and mortality in calves. (Am J Vet Res 2004;65:860–864)

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in American Journal of Veterinary Research