btw here is my past comment to the person who lost their animal. The thought is horrible and sad. I couldn't imagine my life without my best friend.
I too am sorry for your loss, absolutely am and know it would be very hard. Your comment stating "not that I would ever know" however makes little sense as my dog was there for 2 years and did not get sick from water. Agree with you, however, that it only takes one time. My dog fortunately moved to AC without any problems that you stated and adapted fine. Fortunately in another situation had wonderful veterinary care on the island.
Preventative care is absolutely the answer to a good portion of issues.