I loves my dogs! I live in Georgia where we have lots of fleas, ticks, etc! I appreciate reading the experience people have had with Vetbiochem and Pet Shed internet seller. I've decided to stay with Sentinel for my three Dogs. I have used it for several years now with no problems & very effective with fleas & heartworms, etc. Found the best price at Petvaluemart.com Prices 2/16/2019 for 6 does 11-25lb $31.88 26-51lb $37.95 51-100lb $46.68 I will ask my vet if they will match this internet price, if yes I will buy locally! American capitalism keeps America Strong!