Get Your Dog Care Questions Answered by Experts
Hello. I'm sorry to hear about these dogs.
The best thing to do, is get a necropsy done on the dog that just died. It should be refrigerated until it can be taken to a vet hospital. If there is a 24 hour ER vet in the area, you could take it there. They will then probably send it to a pathologist to have the necropsy (autopsy) done. This would include tissue samples, checking for certain toxins and getting a cause of death. If brought where I work, we would probably send the dog to MSU.
Without a necropsy, you're never going to know what happened.
I hope this helps, let me know if you have any other questions.