What news did Bob Volt tell Dan Dalgard? How did that affect his next decisions?

Bill Volt also notices that the heating and air-handling system in the monkey house is malfunctioning. He contacts Dan Dalgard, the consulting veterinarian for the facility, to see if he will examine and treat the monkeys. When Dalgard arrives at the facility a few days later, he identifies two sick monkeys in Room F that seem to be feverish with droopy eyelids. Both monkeys die that night. When Dalgard returns to the facility to dissect the animals, he notices that both monkeys have enlarged spleens and blood in their intestines, but he is unable to identify a specific cause of death. Dalgard suspects that the monkeys may have died from an infectious agent such as simian hemorrhagic fever (SHF). Over the course of the next several days, several monkeys from Room F die nearly every night.