One of my employees was cutting a fenced in back yard at a customers house when out of the blue a little dog came running at the machine. The employee quickly tried to kill the blades but the dogs paw got cut and required medical care. Am I liable for this or is the homeowner responsible for controlling their domestic animal? The fence had no dog warning signs and when the employee looked in the back yard he did not see any dogs present. Has anyone run into a situation like this before?