We've just been away for 3 days. Our regular cat sitter was booked and all good, however - en route to our destination he called to say didn't think he could make it because so unwell and was was very upset he was letting us down. Trust this person implicitly and completely understood. I could have easily returned and said so but he sorted out contingency of someone we also know and a cat person (him and wife have masses) so we were very grateful.
On our return, realised the substitute had been giving our cat a bowl of 'treats' (Dentabytes / Dreamies) twice a day instead of separate bowl of dried food. To clarify, we ask normal cat sitter to give half a pouch / carton of wet food twice a day and scoop of dried food in separate bowl twice a day. Cat food is high quality grain free stuff - also leave print out of instructions / pertinent info.
Sorry about long background but I am worried about any long term effects of cat chomping down on bowls of treats over three days - given that cat normally has very small handful (6 - 9 pieces) doled out last thing.
He's obviously had an upset stomach (evidence) but is drinking loads of water.