Older greyhounds may be abandoned or killed when they stop winning races
Animal welfare groups want new regulations to protect racing greyhounds in Wales.
The campaign is led by the Greyhound Welfare Advisory Board, made up of the Dogs Trust, Greyhound Rescue Wales and RSPCA Cymru.
The board wrote to assembly members saying older or unsuccessful greyhounds are often abandoned or killed.
The Welsh Assembly Government said it was "fully committed" to protecting the welfare of animals.
The campaign is aiming to garner widespread endorsement from AMs and from the Welsh public, leading to a change in the law in Wales.
Spokesman Alain Thomas said: "We know that many owners care well for their greyhounds but we are also aware that others do not and that significant numbers of greyhounds in Wales are abandoned or killed when they are no longer able to win races.
We are hopeful that the assembly government will respond positively to what is a clear, and widely supported case
Alain Thomas, Greyhound Welfare Advisory Board
"At present racing greyhounds are not protected by any regulations."
Mr Thomas referred to the case of Last Hope, a greyhound who was found on Fochriw mountain, near Caerphilly, in May 2004.
"His ears had been cut off, he had been shot in the head and he had been left there for some time but was still alive," he said.
"He was just one of many greyhounds who are shot in Wales each year and regulation is needed to stop this practice once and for all. "
Mr Thomas explained that the Department for Environment, Food and Rural Affairs (Defra) was planning "minimal" regulations for England in April.
"We are hopeful that the assembly government will respond positively to what is a clear, and widely supported case," he said.
The board is pressing for a formal public consultation on the content of the regulation by early summer and to introduce regulations in the autumn.
We were the first administration in the UK to produce a code of practice for the welfare of dogs
Welsh Assembly Government
An assembly government spokesperson said Wales was signed up to the Great Britain animal health and welfare strategy - a 10-year plan of "continuing and lasting improvement in standards of animal health and welfare".
Animal welfare was "a high priority" and the Welsh Assembly Government was the first administration in the UK to produce a code of practice for the dog welfare.
"We note the concerns that have been expressed by the Greyhound Welfare Advisory Board, and we will give them due consideration," said the spokesperson.
"The Welsh Assembly Government is fully committed to protecting the welfare of animals in Wales."
The spokesperson said they were reviewing legislation on the breeding and sale of dogs legislation, with a working group due to report by the end of June.
This will include whether micro-chipping of dogs should be compulsory or voluntary.
"The welfare of greyhounds, as with any other animal, is important," said the spokesperson.
"The Animal Welfare Act 2006 provides for enforcement of measures to protect against unnecessary suffering. We intend to review the relevant legislation as it relates to Wales in due course."
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