The collections were made in the Letterkenny area in recent days on behalf of Donegal Pet Rescue.
A number of young women are believed to have called to housing estates carrying out door-to-door collections.
However a spokesperson for DPR say they have not organised any such collection and believe people may have been acting illegally.
The spokesperson warned members of the public that anybody belonging to Donegal Pet Rescue will most likely be wearing an official DPR vest and carrying ID.
“Unfortunately it appears that this is not a legitimate collection, as they have not been in touch with our fundraising director with regards to this collection,” he said.
It is not known how much money was collected during the bogus door-to-door operation.
Donegal Pet Rescue was set up in 2000 to rehome abandoned cats and dogs across Co Donegal.
It’s a non-profit organization which denies on donations from the public and its patron is Sir Gerry Robinson.