I have a cat so don't hate them. But my SIL is allergic so it would distract her from a house. If there are four and if any have long hairs I'm sure it would put her off because getting rid of the hairs is so hard.
What I dislike about my own cat and would put me off (even though I know I'm not buying it) is unclean litter trays out and the smell of bowls of food around the house. I don't like this smell in our house, never mind someone else's.
Are houses shifting at all in your area though? When we tried to sell a few years ago we couldn't shift my H's old place for love nor money - because people just weren't looking/buying. We waited 6 months, tried again, and got a buyer the first day it was on the market. Things had just picked up in the market a bit. We had thought about making improvements as the bathroom and kitchen were old but worked OK but the estate agents advised against it. I suspect that no-one will be looking this side of Christmas but things normally pick up again in the spring. (I know you are under pressure to sell).