Scotland's animal welfare charity has launched an unprecedented campaign calling for the English and Welsh charity to admit it can't save a single animal in Scotland.
Chief Executive Stuart Earley said, "Many people do not know that the RSPCA does not rescue or rehome any animals in Scotland and by advertising here it has been intentionally adding to the confusion to make money.
"The RSPCA is in breach of Institute of Fundraising guidelines it helped draw up which require charities to be explicitly clear about where they work. Occasionally using small print to tell the Scottish public it is registered in England and Wales is in no way explicit.
"We are a completely separate charity and have asked the RSPCA to make it clear it does not save animals in Scotland so people can make an informed choice about who to donate to. However, after six months of talks we are no further forward.
"This has been increasing the huge pressure on our resources for many years and enough is enough. It's time the RSPCA told the truth."
Research has demonstrated that 70% of the Scottish public believe the RSPCA saves animals in Scotland. High profile RSPCA campaigns in Scotland last year included a membership drive in Scottish supermarkets and adverts on Scottish radio stations.
"The RSPCA seems determined to portray itself as a UK charity, even if it is at the expense of animal welfare in Scotland," said Mr Earley.
"Further RSPCA advertising has included television adverts on UK channels. While these particular adverts cannot be restricted to England and Wales, they should not deceive the Scottish public.
"We are therefore calling for the RSPCA to be explicitly clear in its advertising that it does not rescue or rehome animals in Scotland.
"This could be by explicitly stating where it works or even describing itself as the ‘RSPCA for England and Wales'. Either would clear up the confusion almost immediately.
"We are also calling for the RSPCA to at all times make it clear to anyone donating from Scotland that their donation will not help animals in their country.
"This should extend to any legacies it receives made out to the ‘Scottish RSPCA' or ‘RSPCA Scotland'. We believe these should come to us and be used to care for animals in Scotland but even this basic and fair principle has been rejected.
"It is impossible to quantify how much we have lost to the RSPCA but any loss is damaging because we receive no government or lottery funding and rely on public support.
"While anyone can of course support any charity they wish, we know the majority of the Scottish public would prefer their donations to help charities in Scotland and it is on this basis, in defence of the abandoned and neglected animals in need of our help, that we are taking this stance.
"We did not want to have to campaign in this way and very much hope this brings about a change in RSPCA policy."
Mr Earley continued, "People will ask why we don't merge. The answers are simple, the most significant of which is the Scottish SPCA is subject to Scottish law and, like the police in Scotland, is a reporting agency to the Crown Office, a status far greater than that afforded to the RSPCA.
"Animal welfare is also a devolved issue in Scotland and the Scottish SPCA is in effect a legally recognised defender of animal welfare on behalf of the Scottish Government, which again is a status the RSPCA does not have in England and Wales.
"Indeed, we are extremely proud of our influential role in the development of the Animal Health and Welfare (Scotland) Act of 2006 and subsequent legislation, which is a reflection of the excellent reputation the Scottish SPCA has with MSPs.
"The Scottish public have their own animal welfare charity in the Scottish SPCA and it is essential they are aware of this fact."