Hemolytic anemia is a common veterinary emergency. While the differential diagnosis list for hemolytic anemia is long, clinical findings, laboratory data, and other diagnostic clues can substantially narrow the list of possible etiologies, allowing clinicians to quickly institute life-saving treatment regimens. In this case, the presence of Heinz bodies on blood smear analysis was a key piece of diagnostic evidence that, together with clinical signs and patient histology, allowed for the timely diagnosis and treatment of zinc toxicosis. This case repmi will review the relevant case history, laboratory findings, and diagnosis for a case of Heinz body hemolytic anemia and will describe the pathophysiology and treatment of zinc toxicosis.