What Causes Rouleaux Formation in Dogs?

A dogs' red blood cells are unique; they present as biconcave disks that appear pale in the center. Produced in the bone marrow, healthy red blood cells are round and homogenous, with no nuclei. When an abnormal amount of cells grow, they begin to stack up and cause rouleaux formation.

Erythrocytes, or red blood cells, make up approximate 25 percent of a dog’s total cell count. Red blood cells are constantly being produced in bone marrow. Old cell are destroyed by macrophages in the liver, spleen and bone marrow. Generally, cells in dogs have life spans of three month. Rarely, red blood cells may stack on top of each other like coins, causing the formation of rouleaux.

Rouleaux is often related to protein abnormalities or chronic inflammation, according to Dr. Mary Jo Burkhard. While inflammation in itself may not be a major concern in dogs, how his body responds to the inflammation may lead to rouleaux. Additionally, dogs release an acute phase reactant family of proteins in response to inflammation, which may result in rouleaux formation.

Multiple myeloma is a form of cancer that attacks B-lymphocytes, or white blood cells, which produce antibodies as part of the canine's immune system. Your dog may appear lethargic, weak or sore when moving. He may also experience bleeding from his nose or gums. In response to the invasion of cancer, the dog's immune system produces immunoglobulins. This, in correlation with decreased plasma in bone cells, may lead to rouleaux.

A blood test showing increased serum proteins, particularly fibrinogen and globulins, may indicate your dog is at risk for rouleaux. Also, proteinuria, or protein in your canine's urine, is an indication he is susceptible to rouleaux formation. However, a blood smear viewed under the microscope showing the red blood cells stacked on top of each other is required for a definitive diagnosis. Treating rouleaux involves treating whatever's causing the rouleaux formation. For instance, clearing up the inflammation causing the production of proteins helps stop rouleaux formation, since old stacks of cells die and new single cells form when a normal level of protein or plasma is present.