Melissa Claus

Elevated body temperature is a common finding in patients presenting to the emergency department. Differentiating fever from hyperthermia is an important first step in these patients, as the differentials and required diagnostics and therapeutics will be quite different between the two problems. Fever is an important adaptive response that is present throughout all of the animal kingdom. While it is sentinel of an underlying inflammatory disease, it is generally not harmful and does not require specific treatment in and of itself. Rather, its presence, along with findings from the rest of the physical examination, can help in developing a list of differentials and a diagnostic and therapeutic plan.

Febrile neutropenia in dogs and cats has multiple etiologies. Regardless of the underlying cause, insufficient numbers of circulating neutrophils can affect significantly patient morbidity and mortality. Without these vital cells of the innate immune system, patients with febrile neutropenia have little protection against invading pathogens and are even at risk of developing life-threatening infections from their own commensal microflora. This chapter discusses the normal processes and production of neutrophils, the etiologies of febrile neutropenia, and diagnostic tests and recommended treatments for patients with this condition.