re: Terrance Cody's agent responds to animal cruelty investigation

So are we required by law to have a sick dog treated? There is a difference between abusing a pet and a pet dieing of what appears to be a natural cause that the owner did not cause. If we are required then are pet owners instructed upon purchase that any death of that pet beyond old age could result in criminal charges? I don't have a dog or cat but I have tropical fish. when they get sick they die. Their remains are disposed of naturally in the tank. Does that make me a criminal? If not then why? Is a tripocal fish's life worth less than a dog?