Mikaela, very good point. I think this might happen more often than people realize. I also remember that a couple of years ago there was a heart worm preventative pill that started causing many dogs to have a sudden heart attack. It was pulled from the market but these manufacturers just whipped out another pill under another name. Most people are so traumatized by the sudden death of a pet that they do not follow up with an autopsy. Sadly sometimes many dogs will suffer the consequences of these 'new' drugs before the public is made aware of their dangers.