Ideas please!

Just had a very interesting chat with one of our readers who is writing her will. She wants to split probably £200k between some really deserving charities and I need a little bit of help on this!
There are three areas she wants to help: Horses, primates and dogs.
I can think of lots of lovely doggie charities, but am struggling with UK-based horse and primate.
Margaret wants smaller charities that can really make a difference to the animals.
If anyone can explain what a donation of several thousand would mean to them please post or email and I will forward so she can investigate! She really wants her money to make a difference to the animals.
Please mark your letters 'Margaret's legacy' and I will pass them on.
She's been reading our new Charity Spotlight section in the magazine, so is already aware of those listed - but if anyone could say something like - with £5,000 I could rehome/save X number of dogs - that's the sort of information that would be helpful to Margaret. It really is such a good idea to write a will so your hard-earned cash can really make the most impact.
(Post anything for Margaret's attention to Margaret's Legacy, Dogs Today, 4 Bonseys Lane, Chobham, Surrey, GU24 8JJ and we will forward - would prefer by post please as Margaret isn't on the Internet.)