Footpath question

I have lived near to a yellow signed footpath now for nearly 5 years, all this time there as been horses in said field footpath runs through. I personally have had no trouble with the horses though haven't used the path for a while as there's a better path/walk going oppersite way. About two three months ago I heard a chiuaha(spelt very wrong lol) was trampled by the horses,just after a sign went up saying horses can kick keep to footpath and dogs on lead. Now for my question today I walked by the stole and there's a new sign saying keep out this is private property and not a footpath would they be able to do this or have they put sign up to hopefully stop people going through, im just curious as I said earlier I don't use the path

Sorry silly phone stile not stole

Contact your County Council. It`s almost certain this sign is illegal.

Find out if it's a public right of way (something like an OS map of the area might help)
http://wtp2.appspot.com/wheresthepath.htm

http://www.environmentlaw.org.uk/rte.asp?id=207
I think there are laws about dangerous livestock kept in land with public footpaths too, generally this relates to certain kinds of cattle (e.g. dairy cows as mentioned above) but if the horses have a history of being intimidating they may be falling foul of this.
The Ramblers Association website has a look of info too, unfortunately it's blocked on my work internet but if you want to browse the address is http://www.ramblers.org.uk

Or for a quick look try Street map. (not definitive).