Although the clinical signs of asthma may seem straightforward, the classif
ication of the disease has not been as clear. Even in human respiratory med
icine, it has historically been easier to recognize the clinical signs of a
sthma than it has been to precisely define the condition. The purpose of th
is article is to review our current understanding of the pathophysiology of
asthma in cats, to suggest a clinically oriented classification scheme for
diagnosing and treating cats with asthma, and to introduce the practical u
se of inhaled medications to treat asthmatic cars with mild, moderate, or s
evere disease.