A colleague, called Terry, told me this in the pub some time ago
He was asked by his neighbours to look after their flat whilst they were away for a four week cruise. They gave him a spare set of keys and their alarm system number and asked him to feed their tropical fish, kept in a large aquarium, and their cat. There was plenty of fish food and a whole cupboard full of Kit-e-Kat so all he needed to do was pop round once a day and feed the cat and the fish.
He did this regularly for the first week, but eventually he started staying in the pub late and having one drink too many and so completely forgot to check the flat out.
Finally, he got a phone call from his neighbour who said that their liner was due to dock at Southampton the next day and they would be back the day after and, by the way, how are the fish and the cat?
Lying blindly, he said that they were all fine, no problem at all and then rushed round to their flat as soon as he had hung up the phone.
As soon as he opened the door, he could smell something pretty unpleasant and to his horror, he saw that the cat was floating in the fish tank, stiff as a board and that all the fish had died because the carcass had infected the water!
He put the cat in a plastic bag and dumped it in a skip outside, cleaned up the fish tank as much as possible, aired the flat to get rid of the stench and then waited for his neighbours to get back…
When they got back they called him round and asked where the cat was and how come the fish were all dead.
He just said Oh the cat must have got out somehow, maybe its wandering round outside. Th fish? They were fine yesterday, was it some disease?
The wife then opened the cupboard where the cat food was kept and saw about three weeks supply of unopened tins …