The phrase ‘they fight like cats and dogs’ is universally known. So much so that people who have never owned a pet think that housing both species under one roof is a one-way ticket to tragedy, bloodshed, or a swift renovation of the apartment. In this case, a popular saying resulting from over-simplification and snap judgements is quite unfair to these two animals, and presents a slightly distorted image of their world.
A cat is not necessarily the same thing to a dog that a mouse is to a cat. Dogs don’t eat cats – they chase cats as a result of their hunting instincts. Dogs chase any targets moving away from them, because such behaviour is determined by their DNA. This happens more in some breeds than in others, but all dogs love to pursue moving objects, and we shouldn’t ever forget that. This is not caused by an urge to exterminate a particular species, but simply because a cat is an attractive prize that just happens to be ‘available’ (often more so than a deer or a weasel). Quick and afraid, the cat runs away whenever it feels threatened, while the dog – bored by insufficient movement and a lack of activity – makes its life more attractive by running after the fast furball.