They've ruled out the possibility of an accident or medical condition.
"Terrible pain and suffering has been inflicted on an innocent cat and it is important that those responsible for this cruelty are held accountable so it doesn't happen again," SPCA Auckland CEO Andrea Midgen said.
"This cat is very friendly and comfortable around people, and our team believes she could have had a family.
"We also want to hear from anyone who recognises this cat or can help reunite her with her owner."
SPCA Auckland rescued her, and is now treating her at its animal nospital.
Anyone with information should call SPCA Auckland on (09) 256 7300.