Scientists of Dredd’s world have been able to stimulate unused areas of an animal’s brain to give them almost human intelligence - resulting in speaking animals! They called this genetic alteration ‘Hyper-Intelligence’.
By 2101, experimentation on various animals continued until Judge Dredd saved Monty the Guinea Pig from Doctor Galt, a mad scientist who intended to blackmail Mega-City One. It was after this brief encounter with ‘intelligent’ animals that Dredd changed the Law to protect them from harm and put a halt to the surgery that that created these freaks of nature. (see: The Guinea Pig That Changed The Law – 2000AD prog 126)
The genetically engineered apes were different to the other animals bestowed with ‘hyper-intelligence’ in that they assisted in the building of Mega-City One. With this in mind and their close relationship to humans on the evolutionary scale I personally feel they would have been given rights but ones which were not as extensive as those given to human citizens. They would have been treated as a sub-class of citizen; after all, they were initially created to serve mankind.