Search Results
You are looking at 1 - 2 of 2 items for
- Author or Editor: Sue Beals x
- Refine by Access: All Content x
Abstract
Objectives
To determine efficacy of orally administered Brucella abortus vaccine strain RB51 against virulent B abortus challenge exposure in cattle as a model for vaccination of wild ungulates.
Animals
20 mixed-breed beef cattle obtained from a brucellosis-free herd.
Procedure
Sexually mature, Brucella-negative beef heifers were vaccinated by mixing > 1010 viable RB51 organisms or diluent with their feed. Heifers were fed individually and consumed their entire ration. Each heifer received approximately 3×1010 colony-forming units (CFU). Six weeks after oral vaccination, heifers were pasture-bred to brucellosis-free bulls. At approximately 186 days' gestation, heifers were challenge exposed conjunctively with 107 CFU of virulent B abortus strain 2308.
Results
Vaccination with the rough variant of B abortus RB51 did not stimulate antibodies against the O-polysaccharide (OPS) of B abortus. After challenge exposure and parturition, strain 2308 was recovered from 80% of controls and only 20% of vaccinates. Only 30% of the vaccinates delivered dead, premature, or weak calves, whereas 70% of the controls had dead or weak calves.
Conclusions
Cattle vaccinated orally with the rough variant of B abortus strain RB51 develop significant (P< 0.05) protection against abortion and colonization and do not produce OPS-specific antibodies.
Clinical Relevance
Results encourage further investigation into use of strain RB51 to vaccinate wild ungulates (elk and bison) orally. (Am J Vet Res1998; 59:1575-1578)Vol 59, No. 12, December 1998
Abstract
Objective—To evaluate short-term hemodynamic effects of ecadotril in a model of congestive heart failure in dogs.
Animals—6 conscious adult male dogs.
Procedures—Instruments were placed in dogs to measure left ventricular, aortic, and atrial blood pressures. Heart failure was induced by repeated coronary embolization with latex microspheres. Four times, and in random order, dogs were given vehicle or active drug (3, 10, or 30 mg/kg of body weight) orally. Hemodynamic variables, urine flow, and urinary electrolyte excretion were measured before and 30, 90, and 150 minutes, and 10 and 21 hours after drug administration.
Results—Changes in urine flow, heart rate, mean arterial pressure, or peak positive and negative rate of change in ventricular pressure were not apparent. Urinary sodium excretion significantly increased in response to the low and high doses of ecadotril but not in response to the 10 mg/kg dose. Left ventricular end diastolic pressure (LVEDP) consistently decreased in dose- and time-dependent manner. Maximal group-averaged reductions in LVEDP were 5.2, 8.1, and 10 mm Hg for the low, middle, and high doses, respectively. The magnitude of the decrease in LVEDP was not related to cumulative change in urine flow.
Conclusions and Clinical Relevance—Orally administered ecadotril reduced left ventricular filling pressures in these dogs by a mechanism that does not require a substantial diuretic effect. Ecadotril may be effective for alleviating clinical signs in dogs with left-sided heart failure and may be particularly beneficial for use in dogs that are refractory to traditional diuretic therapy. (Am J Vet Res 2000;61: 334–339)