Particularly, says Fogle, when not putting a suffering animal down: "The most tormenting set of circumstances is when the owner won't allow it.

"As the years go by, it gets more difficult." Experience, he explains, makes vets more confident in their diagnoses – which just leaves more time to consider the plight of both animal and owner. "One of my contemporaries can no longer put animals down," he says. "He can help owners with the decision, but he gets one of his colleagues to administer the injection."

he's seen animals die of everything, and hasn't yet seen one way to go that is "anything like as nice for an animal as being put to sleep".

A 2012 study found that a third of veterinary students had experienced depression, compared to around an eighth in the general population. Vets are also three to four times more likely to take their own lives – significantly more than doctors.

Even PETA (People for the Ethical Treatment of Animals), which has questioned the morality of using guide dogs, agrees that "euthanasia, performed properly, is often the most compassionate option" to "prevent the suffering of unwanted animals in the most responsible and humane way possible".

probably the last one that anybody considers is the vet