This is the best heart worm medicine for greyhounds (according to my vet) it has the added benefit of control of hookworms which many greyhounds suffer with long after life on the track. I really love being able to get this brand which is not available in the US. Budget Pet Care is great to work with. It takes a little longer (1-2 weeks) but it is coming from the other side of the earth! It’s actually pretty phenomenal if you think of it that way. Thanks for doing all you do to help my retired racer!