An ad for the RSPCA's Home for Life service has been cleared following complaints that the charity omitted to mention that it euthanises some animals in its care.
The campaign, headed "You'll rest in peace knowing they're being looked after," said: "When you pass away you'll want to know that your pet is safe and happy.
"You can ensure they will be by registering for the RSPCA's free Home for Life service, and by making your wishes known in your Will. It means we will care for your pet, and do all we can to find them a loving new home."
The Advertising Standards Authority (ASA) received complaints from an MP and a member of the public that the campaign was misleading by omission because it did not make clear that the RSPCA euthanised some animals.
The RSPCA said it "strongly disagreed" that the campaign was misleading, pointing out that the wording only went as far as promising that the charity would do "all we can" and "our very best" to find pets a new home.
It believed the ads struck the right balance between providing enough accurate information to the public without including potentially distressing details about animals which could not be re-homed on medical grounds or were of an unsound or aggressive temperament.
The charity said that in 2011 it had to euthanise 625 re-homeable dogs, 667 re-homeable cats and 91 re-homeable rabbits, but had successfully re-homed a further 60,551 pets.
In relation to the Home for Life service, it had taken in 58 animals last year and had to euthanise 10 of them, including a cat and a dog with tumours and other health problems, a cat with suspected renal failure and a cat with underlying kidney problems.
Rejecting the complaints, the ASA noted that the ads did not state or imply that the RSPCA never euthanised animals.
It said: "We understood the RSPCA were proactive in trying to find animals a new home but there were occasions when they would euthanise animals in their care.
"However, we understood they only did so, on veterinary advice, if the animal was suffering from serious physical or mental ill health, if it had an unsound or aggressive temperament even after behavioural training, or if they were not allowed to re-home the animal for legal reasons.
"We concluded that, because consumers would understand from the ad that the RSPCA would do all it could to re-home pets, which we understood was the case, and because consumers would also understand that there might be instances when it would not be in an animal's best interests to be re-homed, which we also understood was the case, the ads did not breach the code."