After a restless night, Norman refused a treat the next morning. His owners recognized the change and arranged a veterinary appointment that day, setting in motion the discovery of multiple splenic masses before they fully ruptured.
Veterinarian Dr. Rebekah Hartfield found that Norman’s abdomen felt unusually tight. His gums appeared normal, but testing showed slight anemia indicating blood loss, while X-rays revealed a problem involving his spleen.
Hartfield recommended immediate surgery. During the splenectomy, which removed Norman’s spleen, she found multiple masses that had not completely ruptured. Later testing confirmed hemangiosarcoma, an aggressive cancer arising from the cells that line blood vessels.
“We literally saved Norman in the nick of time,” Hartfield said of the surgical findings. The operation addressed the immediate danger from the affected spleen and gave his owners more time with him, but Hartfield stressed that it did not cure the underlying cancer.
Small changes can justify a veterinary call
Hemangiosarcoma often affects the spleen, although it can also occur in the heart, liver and skin. Splenic tumors may develop with few apparent signs until they rupture and bleed into the abdomen.
Decreased appetite, lethargy and unexplained changes in usual behavior can be early warning signs. These changes do not establish that a dog has cancer, but they provide a reason to contact a veterinarian, particularly when they persist or appear alongside other signs of illness.
Norman’s case also shows why a dog’s gums cannot be the only measure of whether something is wrong. His gums looked normal during the examination even though testing found slight anemia associated with blood loss.
Sudden weakness, collapse, very pale gums, or a painful or enlarged abdomen require immediate veterinary attention. The 2023 ABROVET veterinary oncology consensus review also identifies breathing difficulty and fainting among signs that can accompany internal bleeding or shock. Owners who see these signs should seek emergency veterinary care rather than attempt home treatment.
Those symptoms can have causes other than hemangiosarcoma. A veterinarian must evaluate the dog and determine what testing is appropriate.
Finding a mass is not a final diagnosis
Veterinarians may use bloodwork and imaging such as abdominal ultrasound, chest X-rays or CT scans when evaluating suspected hemangiosarcoma. Imaging can locate a splenic lesion and help assess disease elsewhere, but it cannot reliably determine whether every splenic mass is malignant or benign.
A definitive diagnosis generally requires examination of tissue under a microscope. Cornell veterinary guidance notes that biopsy is needed to confirm hemangiosarcoma when a tumor is in a location that can be removed surgically. In Norman’s case, confirmation came after his spleen was removed and the masses were tested.
Splenectomy can reduce the immediate risk of life-threatening bleeding from a ruptured splenic tumor. It is generally not curative for splenic hemangiosarcoma because the disease carries a high risk of spreading beyond the removed organ.
Further discussions may include an oncology referral, chemotherapy or comfort-focused care, depending on the cancer’s stage, surgical findings, the dog’s overall health and the family’s goals. Available evidence suggests chemotherapy may delay progression for some dogs, but outcomes vary, and no single approach guarantees a particular result.
Location matters as well. Superficial hemangiosarcoma confined to the skin may follow a less aggressive course and sometimes can be addressed through complete removal. Tumors beneath the skin or in muscle can carry greater risk, while internal disease involving organs such as the spleen is generally more aggressive. Any new skin mass still requires veterinary assessment because appearance and touch alone cannot establish whether it is cancerous.
Older and larger dogs have been associated with increased risk, and some breed patterns have been identified. Those associations do not prove why an individual dog developed the cancer, and the exact cause is generally unknown.
Norman’s refusal of one treat was not diagnostic. Its importance was that it occurred after a restless night and represented an unexplained departure from his usual behavior. His owners acted that day, creating an opportunity for veterinarians to identify and remove an immediate threat before the splenic masses fully ruptured.
What would you do if your dog were in this situation? Share your thoughts in the comments.
By Sarah Mitchell — 8 years as a local-news reporter covering animal welfare, shelters, neighborhood disputes, and public-safety pet stories.
