It is also vital that you treat not only your pet but also his environment as best you can.
Fleas can live anywhere.
They reside quite nicely in your yard, grass, sand, dirt, carpet, bedding and anywhere else you can think of.
They are resilient.
Persistence is a must.
One study showed fleas that were found in Arctic Turns nests which were thawed out and found to be still viable after having been frozen for a long time.
The fleas life cycle must be broken to gain any sort of advantage at depleting their population.
Treat the house, the yard, and your pets.
Make sure you use products that are safe for all your pets.
