In a round-the-clock operation in August RSPCA staff removed the cats from Hill Grove Farm where they were being bred for research after the owner announced his retirement.
But retired teacher Kit Ineson and his wife Kathleen were not among the 10,000 people who contacted the RSPCA to offer the cats a fresh start — they were in fact out looking for a dog at a local rescue when they stumbled across cats Persil and Zanussi.
Mr Ineson explained: 'We have this very old dog who was really lonely when her sister died so we went to find her a companion at the RSPCA Little Valley Animal Shelter near Exeter.
'There were lots of dogs but none that would suit our situation, so my wife said to look at the cats because we had lost two recently.
'There were these two in a cage who were very alike and loving each other. One was six months old, ginger and white and the other a year and a half old and black and white.
'They were looking at us as if to say please take us out of the cage and we just could not resist.
'It was then that we found out they were Hill Grove Farm cats and the RSPCA did not want them to be separated. They had to go as a pair.'
Mr Ineson said it was a 'sheer fluke' because a batch of ten animals from Hill Grove Farm had arrived at the centre just an hour before he and his wife turned up.
'The charity was taking the cats to centres all around the country and we were in the right place at the right time,' said Mr Ineson.
'I don't think they would have had any trouble getting rid of these cats — they are absolutely gorgeous.
'We have seen the national media coverage about the cats and although we are not animal rights campaigners I believe breeding animals directly for vivisection is disgusting.'
The cats, who have been renamed Tarzan and Topper are getting on well with the couple's other pets which include their new dog Billy.
The RSPCA has reported that almost all the cats have been rehomed and are adapting well to domestic life.
Press officer Jamie Stevenson said the animals, who were being used in research testing for human and animal diseases, had been kept in good conditions but being an organisation concerned with the welfare of animals, the RSPCA wanted to see an end to establishments breeding animals for research.
He added: 'There has been a great response from the British people in providing homes for these animals but there is still a demand for people to take on other cats from rescue centres who desperately need homing.
'If someone did not get a Hill Grove Farm cat don't worry there are many many cats that are still looking for homes,' he said.