Bella, a 5-year-old pit bull terrier, wasn’t feeling well. She was lethargic, had dark urine and was icteric. Her owner, Carol, a veterinarian who graduated from UC Davis, knew something was wrong with Bella, so she started blood tests on her dog. The tests revealed a low red blood cell (RBC) count, and Carol immediately suspected that Bella had a case of immune-meditated hemolytic anemia (IMHA). This can be a fatal disease, as it causes a dog’s immune system to destroy its own RBCs.
Carol moved quickly to treat her dog, and over the next two days, Bella received two transfusions of packed RBCs. She also received treatment to suppress her immune system, but unfortunately, she was not improving or even responding to the care. Carol knew it was time to seek alternative treatment options with the specialists at the UC Davis, and she admitted Bella to the veterinary hospital.
The Emergency and Critical Care Service at UC Davis immediately got to work, administering two additional packed RBC transfusions to Bella after her RBC count dropped significantly overnight from her admission figure. But there was so much breakdown of RBCs that veterinarians with the Internal Medicine Service discussed with Carol proceeding with the use of therapeutic plasma exchange (TPE).
TPE has made headway in veterinary medicine over the past few years as a blood purification procedure, joining the ranks of hemodialysis and hemoperfusion. TPE is an apheresis (i.e., removal of impurities from blood) treatment in which plasma contaminated with damaging (pathogenic) antibodies, toxins or abnormal proteins is separated from the patient’s flowing blood and exchanged with donor plasma that is returned to the patient to render the patient less susceptible to or free from immunologic attack or other pathologic processes.
Bella received three TPE treatments while at UC Davis. After her first day of treatment, she did not need any further blood transfusions. On her sixth day of hospitalization, her RBC count had increased to 32 percent and her reticulocyte (new RBC growth) count continued to show a strong regenerative response to the anemia. Bella was healthy enough to be discharged that day, though she isn't quite out of danger yet. There is still a risk of Bella forming blood clots, which can be a cause of significant mortality in IMHA patients, and which she was prescribed anticoagulant medications for. Additionally, to help suppress her immune system from attacking her own cells further, Bella was placed on an immunosuppressive therapy of medications.
Two weeks after discharge, Bella showed a positive recovery at her recheck appointment. She was bright and her RBC count was at 40 percent, within the normal range. She will need to continue immunosuppressive therapy for at least 4 to 6 months to keep her in complete remission of IMHA.
Bella’s success is how UC Davis is showing TPE to be emerging as an innovation in veterinary therapeutics for IMHA. It should be considered a first-line, rather than a delayed, therapy for animals with severe IMHA unresponsive to initial blood transfusions or medical therapy.
“We are very grateful for everyone at UC Davis,” Carol said. “Her TPE treatments were lifesaving, and everyone treated her with loving care.”