Tolerance to Blood Loss in the Growing Beagle 1

Abstract

Summary

Beagles ranging in age from 7 days to adult were bled to a mean arterial blood pressure of 30-35 mm Hg. After 30 min at this pressure level no more blood was taken and the blood lost was never replaced. In the following 3 hr, blood pressure further declined in puppies 1 and 2 weeks old while there was a partial restoration of pressure in older dogs. Average bleeding volumes ranged from 49 to 50.1 ml/kg in 2-month-old and older dogs and from 41.3 in younger animals. Forty-eight-hour survival rate was zero for 2-week-old or younger animals and was 20% in the adult group. A peak survival rate of 60% was observed in 2- and 3-month-old puppies. There was no statistically significant difference in the magnitude of compensatory fluid shift into the circulation between 3-month-old and adult beagles. Tolerance of 2- and 3-month-old beagles to an acute, large unreplaced blood loss seems to be greater than that of adult beagles and other dogs.