SIR - While I understand Karl Dallas being disenchanted after working for a circus, he claims that man can choose to perform tricks while animals can’t (Letters, September 5).

But is it not unnatural for horses to race one another? Or to dance and walk sideways and backwards (dressage)? Should zoos and safari parks be closed down? When did any animal in captivity have to hunt its own dinner, or evade a predator to prevent becoming lunch. How many wild fish live in waters of just a few feet or even inches of space?

When did parrots in the wild learn to speak or ride miniature bikes or roller skates? Do wild dogs sit, stay or fetch sticks? Farm animals also lead an unnatural life. In the wild would farm animals eat a high protein diet and take steroids so that their lives will be shortened to a few weeks?

No, Mr Dallas, man keeps animals in an unnatural setting for many reasons, so don’t just pick on the one that you don’t agree with. Campaign to have the keeping of all animals for whatever reason banned entirely.

Keith Rayner, Laburnum Drive, Baildon