BST10
Received an email with this coupon code from MyPetWarehouse. I don't know if this is targeted or not. Worked for me.
Canidae All Life Stages 20 kg bag is currently $99.99 (listed) - $10 (coupon) = $89.99 delivered, which is the cheapest I have found lately.
You could possibly save Additional 4.75% with Cashrewards but I know that using a coupon code sometimes doesn't earn a cashback. Still it's worth a try.
Always found these guys a bit more expensive than everywhere else, optimum 3kg $12 delivered isn't to bad