My mother in law has two ‘Italian’ cats. One has worms, the other apparently not. Medication time. The diseased cat refuses the medication, whatever enticements are on offer. The undiseased (or cat at ease) scoffs not only his own medication, but that of his partner.
There are plenty of cats in South Wales, and I doubt that coal dust kills off the worms. Julian (Tudor-Hart), where did the idea come from? [ Yes, before you write in, not quite the inverse care as JTH meant it, but metaphors are the viruses of novelty, so who knows.]