Cats and birthcontrol pills

Question
I live 6-8 months of the year in a remote island in Indonesia. Two years ago i found a dead cat and her two kittens, still alive. I gave them food and looked after them and they are now a big part of our life. However, they are both female and have had their litter so now I have got 7 cats around my house, (all female). They are all quite wild, we have no access to veterinarians on the island and I am desperately trying to find out if there is any pregnancy pills I can get hold of so that they will stop breeding. The rest of the year we spend in London.
When we are not on the island our neighbours are looking after the cats for us and luckily I have been able to ship in cat food and have been able to get hold of worm treatments for them, but our main problem is now trying to stop them breeding. Would be very grateful for any help. Thank you.

Answer
Hi
As you know having them spayed would be the best option but i guess unless you were able to take them elsewhere and have this done this is not an option.

i have heard that there are cat pregnancy pills available from vets, however you would have to go and speak to a vet about this option and if it is available long term etc. i'm sure any good vets will be happy to advise you.

best wishes Kate