A splenectomy is the surgical removal of a dog’s spleen, either partially or completely. It’s one of the more common abdominal surgeries in older dogs, typically performed because a mass has been found on the spleen or because the spleen has ruptured and is bleeding internally. The good news: dogs can live normal lives without a spleen. The harder question, and likely the one on your mind, is what led to the surgery and what the diagnosis means for your dog’s future.
Why Dogs Need a Splenectomy
The spleen sits along the left side of a dog’s abdomen, tucked near the stomach. It filters blood, stores red blood cells, and plays a supporting role in the immune system. Splenic disease is a significant source of illness in aging dogs, and masses on the spleen are relatively common. The most frequent reasons for removal include:
- Splenic masses or tumors. These are the leading reason. A mass may be discovered during a routine exam, on imaging for another problem, or after a sudden collapse caused by internal bleeding.
- Splenic rupture. A mass can rupture and bleed into the abdomen, creating a life-threatening emergency. Dogs may suddenly become weak, pale, or collapse.
- Splenic torsion. The spleen twists on itself, cutting off its blood supply. This can happen alongside bloat (a twisted stomach) or on its own. Signs are often vague, though a vet can sometimes feel the enlarged spleen through the skin. It requires emergency surgery.
- Trauma. A severe injury to the abdomen can damage the spleen beyond repair.
Benign vs. Malignant: What the Numbers Say
If your vet found a mass on your dog’s spleen, the immediate worry is cancer. But the odds are more encouraging than many owners expect. In a study of 182 dogs that underwent splenectomy at a surgical specialty clinic, 57.7% had benign diagnoses with no malignancy at all. Common benign findings include hematomas (blood-filled swellings) and nodular hyperplasia (non-cancerous overgrowth of normal tissue).
Among the malignant cases, hemangiosarcoma, an aggressive cancer of the blood vessel lining, was the most common, diagnosed in 32.4% of all dogs in that study. The challenge is that there’s no way to tell benign from malignant just by looking at the mass during surgery. The removed spleen is always sent for biopsy (histopathology), and results typically take several days to a couple of weeks.
How Vets Decide Surgery Is Needed
Ultrasound is the primary tool for evaluating splenic masses before surgery. It reveals the size, shape, and internal structure of the mass, and can detect free fluid in the abdomen, which suggests bleeding. CT scans add another layer of detail. Research has identified some patterns that help vets assess risk before surgery: 95% of malignant splenic tumors measured larger than 2.5 cm on ultrasound, while 95% of benign tumors were smaller than 2.5 cm. Malignant masses also tend to have irregular margins, appearing in two-thirds of malignant cases, while benign tumors more often have smooth, regular borders.
These imaging clues help guide the conversation, but they aren’t definitive. Fine needle aspiration, where a thin needle draws cells from the mass for examination, can sometimes provide more information before surgery. In many emergency situations, though, there isn’t time for extensive diagnostics. A dog bleeding internally from a ruptured splenic mass needs surgery immediately.
What Happens During Surgery
The surgery is performed under general anesthesia through an incision in the abdomen. There are two types:
A partial splenectomy removes only the affected portion of the spleen. The surgeon ties off the blood vessels feeding that section, then cuts along the line where the tissue changes color, indicating where blood supply has been interrupted. This approach preserves some splenic function and is used when the problem is localized.
A total splenectomy removes the entire organ. This is more common when a large mass is present, the spleen has twisted, or there’s widespread disease. The surgeon carefully ties off or seals each blood vessel connecting the spleen to the body, including short vessels attached to the stomach, then lifts the spleen out. If the spleen is twisted, those ligations are done with the spleen still in its rotated position to avoid releasing harmful byproducts into the bloodstream.
Recovery After Surgery
Most dogs stay in the hospital for one to three days after a splenectomy, depending on how stable they were going in. Dogs that arrived as emergencies with internal bleeding generally need more monitoring than those with planned surgeries.
Once home, activity should be restricted for at least one to two weeks. That means no running, jumping, or rough play, just short leash walks for bathroom breaks. Skin sutures or staples are typically removed 7 to 14 days after surgery, though some vets use dissolvable stitches placed under the skin that don’t need removal.
Your vet may recommend an iron supplement to help your dog rebuild red blood cells, especially if there was significant blood loss before or during surgery. Appetite usually returns within a day or two, and most dogs are noticeably more comfortable within the first week.
Cardiac Arrhythmias After Surgery
One important complication to be aware of: heart rhythm abnormalities are common after splenectomy. In a prospective study using continuous heart monitors, 22 out of 50 splenectomized dogs developed rapid ventricular tachycardia, a type of abnormally fast heartbeat originating in the lower chambers of the heart. The risk was dramatically higher in dogs whose splenic masses had ruptured (16 of 23 dogs) compared to those without rupture (1 of 17).
These arrhythmias typically occur in the first few days after surgery, which is one reason dogs are monitored in the hospital during that window. Notably, standard spot-check heart readings every six hours were unreliable at catching these episodes, even when they were happening frequently. Continuous monitoring is far more effective. Most post-surgical arrhythmias resolve on their own, but some dogs need medication to stabilize their heart rhythm during recovery.
Life Without a Spleen
Dogs can live perfectly well without a spleen. The body’s other organs, particularly the liver and bone marrow, compensate for the spleen’s blood-filtering and storage roles. You won’t need to make major lifestyle changes for your dog. There is a modestly increased vulnerability to certain blood-borne infections since the spleen plays a role in clearing bacteria from the bloodstream, but this rarely causes problems in practice for most pet dogs.
The far bigger factor in long-term outlook is the biopsy result. If the mass turns out to be benign, your dog’s prognosis is excellent, and many go on to live a normal lifespan. If the diagnosis is hemangiosarcoma, the picture is more serious. Among dogs with confirmed splenic hemangiosarcoma that survived at least the first day after surgery, median survival time was around 80 days. Chemotherapy can extend that in some cases, and your vet or a veterinary oncologist can discuss whether that’s appropriate for your dog.
What Splenectomy Costs
Pricing varies by location, hospital type, and the size of your dog. At a veterinary surgical specialty practice, estimates including imaging, anesthesia, medications, and histopathology range from roughly $1,750 to $2,500. Smaller dogs fall on the lower end; dogs over 60 pounds are on the higher end. Emergency scenarios, complications, or additional procedures like blood transfusions can push costs higher. General practice hospitals may charge less than specialty centers, so it’s worth asking for a detailed estimate. Many clinics offer payment plans or accept veterinary financing.