News that Barkers, makers of dog food has screened a TV ad with a high frequency sound that only canines can hear has been met with some scepticism. After all if humans can’t hear it how can anyone know it has gone out, unless they have dog that barked at the screen at the appropriate moment, of course. Or was it just a cunning stunt to generate some publicity?

Meanwhile a rumour that the secret sound was a message to dogs to bite their owners if they didn’t buy them Barkers should, in our view, be treated as just silly.