Of the 11 birds, two were in poor condition and nine were dead.
The RSPCA were alerted to the property by a member of the public and it is unclear how long the animals had been there, although it appeared someone had been leaving them water and food to some extent.
The dogs and birds were taken to a vet, while arrangements for the cats, who were not in need of urgent veterinary attention, were made.
However, by the time RSPCA staff turned up to collect the animals, there were only eight cats left, suggesting someone had privately removed more than 20 of them.
Chief inspector Amanda Swift said the interference was disappointing and had jeopardised their investigation and collection of evidence.