Dr Michael Morris - Animal welfare writer Dr Michael Morris has a PhD in zoology from the University of Auckland. He is presently teaching degree courses in environmental management at the Bay of Plenty Polytechnic.

A Code of Welfare for dogs was promulgated last month. In general it contains useful advice and minimum standards concerning such husbandry practices as desexing, provision of exercise, and correct feeding - advice that most dog guardians would have little to argue with.

The Code however contains one anachronism, when it allows cutting the "dew claws", and docking the tails of puppies less than four months old. In spite of their name, dew claws are not inert nail tissue, but living digits, with their supplies of nerve tissue. Cutting these is equivalent to cutting off one of our fingers or toes.

A puppy dog's tail also has a nerve supply. Behavioural observations provide plenty of evidence that the procedure causes acute (short term) pain. There is also evidence that tail docking in puppies (and in the young of other species) causes chronic (long term) pain. Dogs and other animals often develop nerve bundles called neuromata in the stumps. These have been associated with chronic "phantom limb" pain in human amputees. It is very likely that dogs are suffering in the same way.

Given the abundance of scientific data, it is quite incomprehensible that the National Animal Welfare Advisory could state that there is "no available evidence" that banding puppies' tails causes any pain or distress.

It is apparent that NAWAC have been unduly influenced by the Kennel Club, who support tail docking for trivial reasons of appearance. But the Kennel Club would have been less successful if they were not aided by a prevailing mythology that young animals do not feel pain. There is no scientific evidence for such an assertion; in fact available evidence seems to suggest that the young of all species (including our own) may be more sensitive to pain because their pain inhibition pathways are still poorly developed. Nevertheless, codes of welfare for sheep, cows, pigs and layer hens all allow surgical mutilations of young animals. Even human babies are not immune from this mythology; until recently it was quite common to circumcise babies without anaesthetic, though the pain from cutting this sensitive tissue can hardly be contemplated.

Routine docking of the tails of puppies, lambs, piglets and calves, castration of lambs and calves, dehorning of calves and kids, and circumcision of babies are based on outdated superstition. The cruel practice of docking puppy dogs tails simply for appearance should certainly not be tolerated.