I would appear that Amazon is rolling out a pet supplies range when it opens it platform this week.
A quick search when you can get behind the first firewall shows a complete line of pet products. Couldn't find foods however it would appear likely that that is there as well.
That aside, not sure how much fulfilment or price advantage this will have over a street front store.
Seems like K-mart and the rest have also jumped into the pet products range extensively. You can't get your dog washed at Amazon or K-Mart though.