Just got my first order from My Pet Warehouse and included in the package was this coupon for $10 off.
Minimum order $49.99 (making it up to 20% off). Expires March 31st, 2016.
It seems like a generic coupon. However, you may need to have an account, or possibly even have placed an order with them before for it to work.
Also like to mention that they offer free shipping on orders over $49.99.
While I have your attention, just like to point you in the direction of Pet Food Reviews Australia. We just got a puppy, and after spending about 10 minutes on this site I quickly learnt that price doesn't always equal quality. Just because something has 'science' in the name, or is endorsed by a celebrity vet, doesn't mean its the best for your pet. We settled on Black Hawk Puppy and it is a lot cheaper, and more nutritious than many other 'good' brands.
Thanks OP, worked for me!