Septic shock in colony bred puppies versus random source puppies

Many shock studies utilize unconditioned random source animals. To determine whether unconditioned random source dogs and colony bred dogs differ in response to septic shock, the following experiment was undertaken. Colony bred puppies and unconditioned random source puppies were pretreated with methylprednisolone and were subject to live E. coli induced septic shock. Resuscitation was carried out with Ringer's lactate and 5% albumin. Cardiac output dropped to less than 50% of control values in all animals. The colony bred puppies maintained a significantly higher cardiac output and pulse pressure and required a longer time for their cardiac output to decrease to 50% of control levels than did the unconditioned animals. In addition, the serum acid phosphatase rose significantly (indicating cellular damage) in the unconditioned group and did not change in the colony bred dogs. Marked hyperglycemia occurred in the unconditioned puppies whereas only a mild decrease in serum glucose was seen in the colony bred animals. These data indicate that extreme caution should be exercised in interpreting the physiological response of the unconditioned animal to experimental septic shock.