It is the fear of teachers and parents alike. You take the class hamster, rabbit or gerbil home for the weekend... and it dies.
As little Fluffy lies stiff in his cage, the temptation is to nip down to the pet shop and find a look-alike. But fobbing off pupils by secretly replacing dead classroom pets is not helping them.
That is the verdict of a pet bereavement specialist after The TES asked staff how they had handled the death of a school animal.
Dozens emailed or posted views on the TES online staffroom forum. Some admitted buying new goldfish and gerbils to avoid upsetting pupils. None said they had been rumbled.
But Margot Clarke, telephone co-ordinator of the Pet Bereavement Support Service, run by the Blue Cross and SCAS animal charities, said that while the death could be upsetting, it should be tackled.
"It may be a child's first experience of a death which can lay the foundations of how they deal with future losses," she said.
"You have to acknowledge the death. It's no good saying, 'Billy the rabbit died last night, now can you open your maths books please.' Some children will be casual about it, but others will get quite emotional."
Ms Clarke said "rituals", such as funerals, had been shown to help children. Teachers on the online forum told of lavish services. In one case, the same hamster was buried twice in a day.
"We had a funeral with the morning group, then buried him on a little plot of land near the classroom," a teacher wrote. "Then at lunchtime I dug him up and we buried him again with the afternoon group."
Several teachers were against the "replacement" technique. One wrote: "The whole point of having an animal in the classroom is to teach the kids about animals, their ways, their classification, their diet. One thing animals do is die. They may whip each other up into a minor tear drama, but it'll soon blow over."