Bark n Fly day care centre told the Daily Record: “A senior member of the Bark n Fly team immediately took Lani to their vets where she was examined. Sadly, there was nothing they were able to do, confirming Lani had sustained a single fatal puncture wound through her intercostal muscles.
“As there had been no audible evidence of altercation between any of the four dogs in the field, it was accepted that there was no requirement to report the incident as one of the brutal or aggressive behaviour of any of the other dogs.
“All parties agreed that it was a tragic accident. It was impossible to say which of the three other dogs had caused the accident and, as a result, inform the owner of the dog responsible.”
So, because you can't identify which of the dogs (that you claim was in the field with the dead animal at the time) killed it, it's 'Oh well, shit happens'?
I hope the owner sues you into the ground.