That sux . It does however sound like you live in a very rural area. I assume people who have cornfields are not walking there dogs on a leash. Sounds like bad luck . Also the owner sounds like a conserned party in this . Some would have told you to F off , not check up on you. This is a tuff one. I live in NY and if a persons dog was off the leash , i'd be whipping them both. Again , this is a tuff one. Hope u feel better ASAP.
Does your insurance cover this ? If not they should pay for your med bills. Is the dog dead ?