Maybe you have found what you were looking for by now, but if not maybe its Doin' the Horse by Skippy Brooks Combo. Its on You Tube.
Are you sure its from the 50's?
It sounds very like a Jonathan Richman track from the 70's.
http://www.youtube.com/watch?v=GdZAQwIMx7k
Ha ha - that is very well known. It's not horses hooves but some type of percussion instrument. 1970s hit so your description had me thinking about the wrong genre/era. Nearest I was thinking of was Dick Dale.
Damn, you've gone and got it - I was going to suggest you created a SoundCloud.com clip of you humming it for us all to have a laugh, sorry, I meant listen
This is the best clip by far
http://www.youtube.com/watch?v=gg7WG6tCbrw
and this is even better
http://www.youtube.com/watch?v=bmnlXQffeNo
Its driving me mad trying to find what a 50s ?? guitar band instrumental with horse clip clopping sounds is titled.
I have heard it a good few times ....
......and the key is that its a guitar band instrumental with a horse clip clopping sound in the background.
I will have to go and sing it in a oldie record shop at this rate That will be embarrassing!
You know it goes dum dum dum da da da da dum ,dum dum dum da da da dum in quite a deep guitar tone with the coconut sound in the back ground
Yes Im going mad! Do you just hate it when you dont know the name of a track. I'm not even massively into it. Oh well worth a try. Should I offer a small prize as an incentive ?