The phrase "best flea" means the most skilled or outstanding person among a group, even if they are small or insignificant compared to others. Full definition
There are plenty of great shampoos out there, but there isn't just one best flea shampoo for cats considering that each cat is different! (happypetsnow.com)
This is the rated as the third best flea collar for dogs and provides seven months protection against fleas and ticks. (happypetsnow.com)
Don't forget that treatment of other pets and the environment is very important for good flea control. (tampabayvets.net)