Some friends of ours use the collars I believe you are referring to (Seresto??). They like them.
We use 4-Legger shampoo w/natural flea repellant, frontline plus, and capstar if I take him somewhere that has flea risks (dog park, friends w/dogs, etc).
__________________ Mario  was adopted May 2015. Now he is a service dog and brother to Bailey the Airdale mix  |