‘November' is a 6 year-old male cat that came into Pascoe Vale Vet Hospital for a urinary tract problem earlier this year. On clinical examination we found November happened to have rear dewclaws or as we like to call it ‘thumbs on his ankles'. Now this is a very unusual occurrence in cats and we have only seen this in a few cats (although it is a lot more common in dogs).
The dewclaws were very subtle and could have easily been missed. November's owner needs to keep an eye on the length of the nails on the dewclaws to ensure they do not become ingrown but otherwise there should not be any problems with them. It may be worth just feeling your cats back legs to see if they have any extra toes as well.