Final answer:
Rouleaux formation is the finding supported by a feline blood sample exhibiting stacked red blood cells that disperse upon addition of saline.
Step-by-step explanation:
The finding that would be supported by a feline blood sample exhibiting stacked red blood cells observable with a microscope that, upon addition of saline, results in dispersed cells, is Rouleaux formation.
Rouleaux formation is the stacking of red blood cells, which can occur due to a variety of conditions and diseases. When saline is added to the sample, the cells should disperse, indicating Rouleaux formation. This phenomenon is caused by the interaction between the surfaces of red blood cells and various factors in the plasma. An example of Rouleaux formation is seen in multiple myeloma, a type of cancer that can cause abnormal proteins to accumulate in the blood.