I’ve sat 2 dogs who died shortly after the sits. Both were ailing when I took on the sits.
One was a fairly young labradoodle. He was one of a trio of dogs and pair of cats near Austin, Texas. The HO called me a few days before the sit was to begin to let me know that Jasper was ‘under-the-weather’ but had seen the vet who didn’t think it was too serious and making sure I’d be okay pilling him twice a day. When I got there Jasper was only eating occasionally and had gotten picky about which canned food he would eat. I actually went to 3 places to find the one thing he would eat. He was quiet but seemed okay through the sit. About 2 weeks later the wrote to let me know that they’d put Jasper down after the vet discovered cancer. And I understand that the HO didn’t do the tests for cancer before leaving on his trip. The dog didn’t really seem that sick. His review noted “one of those dogs is ailing and Tom was super communicative letting us know how he was doing.” From the picture, you can see that Jasper was doing okay while we were together.
My second experience was earlier this year, sitting 3 dogs, a cat and a macaw. There is a long thread that I started Lessons from sitting an old dog (or any animal, I think) - Sitter Questions, Advice & Chat - TrustedHousesitters Community Forum
I kept the dog as comfortable as I could and he died a few hours after the HOs returned. The HO noted my care in the review. That one was harder because the dog was really ailing. But at least he got to spend some time with his family.
It is hard but we do the best we can to help the animals live the best lives they can and to ‘stick around’ for their family’s return. And if the pet seems to be ailing during the sit, to help the pet family with good communication. The only way to really protect yourself is to not sit senior animals but that won’t be perfect.