Okmulgee authorities are calling it the worst case of animal cruelty they've ever seen.
What makes this crime unusual is the person poured "acid" on a dog while it was chained inside a fenced yard.
Okmulgee Animal Shelter Director Debbie McBee says the injuries to the dog were bad. "I was sick at my stomach, I really was. I know what I feel like to get a little burn on my finger and to have your whole back burned like that, it had to be awful."
Officials decided to put the dog down.
No one has been arrested. If you have information, call the Okmulgee Police Department at 756-3511.
A $500 reward is being offered.