We had to use Diamondback drugs for several years when our dog had liver problems. They have GREAT customer service. Every time I had a question for them they answered it promptly and when I needed refills they always faxed to Banfield very quickly. I started asking them for 90 day supplies at a time because the shipping was the same for 1 month or 12 months, they contacted my vet right away and got the approval. They have way better customer service than my own pharmacy for myself (not pet) .....