Helio de Morais, DVM, PhD, DACVIM

Influenza A viruses are divided into subtypes according to the serological reactivity of the surface glycoproteins hemagglutinin (HA) and neuraminidase (NA).

Leptospirosis: Spirochete with more than 200 "serovars."

Empiric antibiotic therapy is the appropriate use of antibiotics without knowing the agent or before its susceptibility is known.

Cough is one of the body's defense mechanisms to prevent the entry of noxious materials into the respiratory system, and to clear potentially harmful debris from the lungs and respiratory tract.

Bronchial diseases are common causes of loud cough and dyspnea in dogs and cats.

Parenchymal pulmonary diseases usually restrict expansion of the lungs leading to dyspnea, and may be occasionally with soft cough.

Fever of unknown origin (FUO) is defined in human medicine as a temperature elevation for 3 weeks or longer, the cause of which is not diagnosed after 1 week of intensive in-hospital investigation.