It seems like it may be all too common to get this type of treatment from our law enforcement and legal system. Our house was robbed a few months ago and they actually caught the guy with one of our stolen items in his hands a few hours after it happened. It had GPS tracking and we had to track it ourselves, but at least we lucked out and got an officer willing to go to the coordinates we gave him and arrest the guy. But we had the worst time getting anything else out of the police or the DA. They refused to get a search warrant to look for the rest of our stuff. It was a pure PITA and we could never even manage to get the recovered item back even though it was absolutely positively identified as ours. We were given a date of the first court appearance, but never notified when the date changed. Nothing. All we got was the ol' runaround from everyone we talked to. Finally, we were notified after he was convicted of probation violation (that was all he got). We had to look it up ourselves to find out if he went to jail or not.
But in this case a life is involved and they *really* should be more cooperative. Even if it is "only" an animal. I wish you good luck getting Max back. I sure hope he is safe and well. What a ridiculous mess!