A friend recently remarked that she had been obliged to take her cat to the vet for the third time this year. When asked if the animal had contracted some nasty virus she replied: "Oh, it's nothing like that. My cat suffers from depression." If the cat had been present to witness the ensuing howls of laughter from the assembled throng, he would no doubt have gone into terminal decline. And, strange as it may seem, he would be right to deplore such a display of callous human ignorance. For feline depression, as it turns out, is nothing unusual, with eight out of ten vets in one survey reporting cases of stress and depression in animals left alone at home while their owners go out to work (BBC Online, 25 August 05).