I've used Petbucket for about 16 years - various products. **I still have our dogs tested for heartworm annually.** Never had a problem with any of my orders. I didn't realize the UK version covers more than USA. Our vet started our latest addition on Nextgard + and I may change our other 2 from what they're on now to Nextgard Spectra. Prices are great & shipping rarely takes as long as they say it can.