Could be a dry run. Imagine if they contaminated Campbell's soup or McDonald's ketchup.
"Could the dog food contamination be
an act of terrorism?"
In earlier threads on TM there were some intercepted chat messages/translations that referenced a dog disease or diseased dog so yes it could be terrorism or a test run...or there could be human food contamination that hasn't been recognized yet. Was the rat poison in the grain that was mixed into the pet food? Where were the QA folks for the manufacturer?