The dogs in the study underwent a range of cancer surgeries, including mandibulectomy, or removal of part of the lower jaw bone; maxillectomy, or removal of part of the upper jaw bone; chest wall resection, which is performed to remove a section of the muscle and ribs of the chest; and liver lobectomy, which involves removal of a tumor of the liver.
In these complicated cancer surgeries, the patient has a high risk of blood loss, so the surgeon knows ahead of time that the dog may need a blood transfusion. In many cases, veterinary surgeons manage this by making sure they know the patient’s blood type, and using blood from a veterinary blood bank if they decide the patient needs it during the surgery.
But using banked blood is expensive, and maintaining a blood bank is labor intensive. “And, personally, because banked blood is a limited resource, I’m always thinking about whether that next emergency case might need the blood more,” says Dr. Sarah Boston, the veterinary surgical oncologist who was the primary investigator of the study.
In this study, Dr. Boston and her colleagues tested an approach that’s commonly used in elective surgeries in humans with a high risk of blood loss called autologous blood transfusion. Before surgery, the patients donated their own blood, so that it would available for transfusion if needed—a luxury veterinarians don’t have when it’s an emergency surgery.
The veterinary team took the patient’s own blood at least six days before surgery, usually when the dog was already at the practice and sedated for diagnostic tests, to minimize stress. “We tried to hit a window that would give the dogs time to replace the red blood cells we took, but we couldn’t wait too long, because the stored blood only lasts about a month,” says Dr. Boston. “One thing I didn’t anticipate was pet owners’ enthusiasm for this approach. Many of them had heard about this approach on the human side and they really appreciated that they could do this for their pets.”
The medical team separated the blood into fresh frozen plasma and packed red blood cells, which is what gets administered during a transfusion, keeping the red blood cell count up and ensuring an adequate supply of oxygen to the patient’s tissues. Separating the blood and freezing the plasma helps the elements of the blood last longer.
Dogs received their own plasma at the start of surgery, and their own packed red blood cells at the first sign of hemorrhage during surgery.
In some cases, dogs have reactions to banked blood transfusions. However, none of the dogs receiving their own red blood cells developed transfusion-related complications.
The medical team checked the percentage of red blood cells in the dogs’ blood before and immediately after the surgery, and 24 hours after the transfusions. “The results 24 hours later were almost identical to the results pre-surgery,” says Dr. Boston. “That’s good news, because you want good oxygenation for wound healing.”
“One of the real upsides of this approach was that I felt so free to give the transfusion,” says Dr. Boston. “In the moment of making this decision in surgery, I didn’t have to think about the cost to the client or worry that I was taking the blood from an emergency patient who might need it more.”
“And it’s exciting to share the good outcome from this research. It’s such a practical option for veterinarians—an idea that’s easy to use. And it could lead to other applications. I had a colleague who was going to perform surgery on a bear and needed to be prepared for a transfusion. You can’t just go to a blood bank for that.”
Sarah Boston, DVM, DVSC, DACVS, ACVS Founding Fellow of Surgical Oncology, ACVS Founding Fellow of Oral & Maxillofacial Surgery, is a surgical oncologist at VCA Canada Mississauga Oakville Veterinary Emergency and Specialty Hospital in Ontario, Canada and an adjunct faculty member at the University of Guelph. Dr. Boston joined the VCA family in February 2018. She is Past-President of the Veterinary Society of Surgical Oncology and has authored numerous journal articles and textbook chapters on surgical oncology. Sarah is also a cancer survivor and author of Lucky Dog: How Being a Veterinarian Saved my Life. In her spare time, she enjoys writing and stand-up comedy, as well as spending time with her husband, Steve, and their dog, Rumble.
“"It’s exciting to share the good outcome from this research. It’s such a practical option for veterinarians—an idea that’s easy to use. And it could lead to other applications."”