Hi Roy
Yes indeed I can see a resonable counter claim here against the stud farm. A claim is based on negligence and it seems you did everything you could to avoid the horses and unfortunatley could not. The issue is whether you were driving negligently, this is obviously something that a solicitor can deal with for you.
The main issue revolves around why the horses were there? They were there solely due the the negligence of the stud farm in that they did not secure them correctly. I would therefore say that your counter claim would be stronger than their claim against you.
I would ask your insurers NOT to admit liability on your behalf and to ensure that they deny liability and make a counter claim for the damage to the car.and personal injury. If you took out legal expenses insurers ask the insurers to appoint solicitors as this will be the easiest way of dealing with the matter. Most no win no fee solicitors will not deal with counter claims, which is what this is.
I hope this helps.