Hello all. I have a labrador adult and need help with flea/tick protection. He was on advantage ii for fleas but I have found out that its becoming less effective. I put the drops on correctly and still the fleas are fierce. I have resorted to simply giving him capstar to help with fleas but thats becoming quite expensive as its a daily pill. I was considering Nexgard because I have two ferrets that I let free roam and I do not want the ferrets to have contact with any drops on my dog. Please help with suggestions. Thank you all so much.