(Portland, OR)  --  A Portland couple is suing Walmart, claiming that the retailer's pharmacy killed their dog.  The Oregonian reports that Elise and Nick Carter's suit alleges the pharmacy at the Wood Village Walmart Supercenter sold them the wrong drug.  The pet had diabetes, and their vet prescribed Novalin N, but the pharmacy sold them the over-the-counter Novalin R instead.  The drug reportedly didn't work as the prescribed one should have and Bailey passed away.  They're seeking compensation for the dog's care, their travel expenses and the cost of a new dog.