Final answer:
The susceptibility to hyperpyrexia and malignant hyperthermia from anesthetic agents like ketamine and isoflurane can vary among species, with pigs being notably susceptible to malignant hyperthermia.
Step-by-step explanation:
The question pertains to which species is most susceptible to hyperpyrexia and malignant hyperthermia from intravenous (IV) drugs such as ketamine and inhalant anesthetics like isoflurane. The susceptibility to these conditions can vary greatly among different species due to differences in physiology. While the provided information does not specify which of the four listed species is most susceptible to these anesthetic complications, it is generally accepted in veterinary medicine that all species can potentially experience adverse reactions to anesthetic agents. However, pigs are notably prone to malignant hyperthermia, particularly with the administration of certain inhalant anesthetics. In the clinical setting, precautions are taken when anesthetizing potentially susceptible species, including monitoring and using alternative medication when necessary.