I have recently been involved in an accident whilst riding to work. I had just pulled out of my street when a dog ran across my path causing me to fall off. Luckily I was travelling at slow speed so suffered no injuries, however my brand new motorcycle was badly damaged. I have asked the owner to pay for the repairs, but he has refused and told me that I should have been able to stop in time.
The owner has a duty to keep control of his dog. The Highways Code states that dog owners must not let a dog out on a road on its own and must keep it on a short lead when walking on the pavement. If the dog was off its lead and shot across the road into your path then you likely have a good case against the owner for failing to control his dog. It would be sensible to ask the owner if he has any public liability insurance as this often covers this type of incident. If not, or if the owner is not willing to engage with you then you will need to consider whether it is worthwhile bringing a claim against him.
In this situation and if you benefit from your own comprehensive motorcycle insurance then you may be best utilising your policy. Your insurer can repair your motorcycle and then use their recourses to seek to recover these costs from the dog owner. Depending on the terms of your insurance you may be left to pay the excess, but this may be the least bad option when compared to bringing against the owner personally.