So, no matter which way you choose to go, getting the upper hand against fleas quickly, before they get out of hand, is a good policy to keep you and your pets happy and comfortable in this worse than
normal flea season.
Moreover, even an individual animal's needs may fluctuate, depending on the
season, his activity level,
normal variations in hormone levels and organ functions, infections, parasites like
fleas, illness, and a host of other factors.