It depends on the circumstances but there have been decisions in the past by courts and authorities to suggest that it is the nature of a dog to kill and wound small animals. Therefore, in the event of your pet being wounded or killed by a dog, it is not a certainty that the police would take any action. However, the police will take action if the dog was 'dangerously out of control'.
If the police do not take action the other possible recourse is to take civil action against the dog owner but this would depend on the circumstances.
To allow us to assess whether this requires a police response please contact us and provide as much information as possible about the incident, the dog involved and if you are aware of who the owner is.
There are however different regulations where the attack involves farm animals and this answer does not take into account deliberate attacks or dog fights which are offences. In all circumstances where you suspect that dog fighting, hunting with dogs, attacks on farm animals or deliberate dog attacks are in progress, are planned or have taken place please contact us online or via telephone on 101 to report.