Having been involved with major charities for several years before my present job, I am absolutely appalled at the waste that goes on. I would encourage anyone to obtain a copy of their accounts from the Charity Commission just to see how much they spend on "admin and marketing" - ie look at the real cost of them raising every pound. Looking at the level of their reserves (ie if all the money stopped tomorrow, how many years could they continue their service provision at that level - some have 5 years' worth).
Consequently I don't give to major charities and only to the local ones.
Indeed when I recently lost my cat, a major national charity was more interested in getting my bank details than the welfare of my animal. Conversely, the local stray cat fund could not have been more helpful - their only concern being the cat. Any guesses which one got a donation with my grateful thanks?