A lot of people may be more familiar with Heinz as ketchup but for this question. This is not referring to ketchup but rather the denatured hemoglobin that can be found in the red blood cells.There are some living things that start to experience this when they are suffering from chronic liver disease.
Exhibiting Heinz bodies means that there are some red blood cells that have been destroyed because of various reasons. There are also some dogs and cats that may start to show symptoms of having this after eating food products that are not right for them.
A talasemia is characterized because of deficiency of the a chain, when there is the phenotype where you can find heinz bodies its correspond to the genotipe --/-a so it cant be because of excess of chain a