A dog lover from Gloucestershire is arguing that a lurcher puppy he wants to adopt should not be castrated.
Peter Martin and his wife Tina want to give a home to nine-month-old Humbug, but a rescue charity says its policy is to castrate all dogs before adoption.
Mr Martin, from Tetbury, disagrees and believes the dog should have a vasectomy instead.
Greyhound Rescue West of England says a vasectomy is not a recognised procedure for dogs.
'The only way'
Rachel Grocott, chief executive of the Somerset-based charity, said: "There is a huge problem in this country with there being too many dogs in need of good homes.
"We are a rescue, rehoming and welfare charity and we cannot possibly contribute to that problem.
"The only way of ensuring we don't contribute to that problem is to castrate dogs to make sure that they cannot father puppies in the future."
Mr Martin, who says he has owned lurchers for 18 years, wants Humbug to have a vasectomy rather than having the testicles removed completely.
He said: "Having his testicles affects the way other dogs relate to him and the way he relates to other dogs, and it is not fair to mutilate animals on ideological grounds pretending that it is something to do with medical grounds.
"There are no good medical reasons for castrating a dog unless you can see the symptoms first.
"I've made them an offer which they haven't responded to, to let us have Humbug intact for four months, until an inspection, and if he has turned into an aggressive sexual predator with testicular cancer by then, then fine, they can castrate him.
"But if he hasn't then let's just give him the snip and not the chop."
The British Veterinary Association says there is "merit in both arguments" but that vasectomies are not routinely performed in dogs.
President-elect Robin Hargreaves said: "Population control is the main reason that many rehoming charities have a castration policy. A vasectomy is likely to be a more expensive procedure and less reliable than castration."