Spleen Functions, Hematoma, and Removal (Splenectomy) in Dogs

Linda Crampton is a biology teacher, writer, and long-time pet owner. She currently has dogs, cats, and birds in her family.

The Spleen: An Important but Not a Vital Organ

The spleen is a very useful organ in both dogs and humans. Although it has important functions, it's not essential for survival. A splenectomy is the recommended treatment for certain disorders. In dogs, one of these disorders may be the presence of a hematoma in the spleen. A hematoma is a swelling filled with blood, which may be in either a liquid or a clotted form.

One of the dogs in my family received a diagnosis of a hematoma in his spleen and was treated with a splenectomy. In this article, I'll describe my dog's experience and also provide information about the spleen and hematomas.

I'm a science writer, biology teacher, and long-time pet owner, but not a vet. If your dog is exhibiting similar symptoms to the ones that I describe or has any symptoms of ill health that don't disappear quickly, make sure that you consult a veterinarian. The vet will offer specific advice and treatment for your dog's particular situation.

Location of a Dog's Spleen

A dog's spleen is located near the stomach on the left side of the abdomen (from the dog's point of view). It's dark red in color and is an elongated organ that is often described as being tongue-shaped.

The size, shape, and position of the spleen vary slightly in different dogs. The spleen's position is also affected by factors in its immediate environment, such as the fullness of the stomach.

Functions of the Spleen

The spleen's functions are related to the circulatory and immune systems. The organ is covered by a fibrous capsule and contains two contrasting types of tissue—red pulp and white pulp.

  • The red pulp makes red blood cells in the fetus. After birth, most of these cells are made in the blood marrow inside certain bones instead. In dogs, however, the spleen can increase its production of red blood cells if necessary. The cells carry oxygen from the lungs to the tissues and organs.
  • The spleen stores whole blood and acts as a reservoir in case the body needs extra blood. In this case, the spleen contracts and pushes the blood into the circulatory system.
  • The spleen also stores red blood cells and platelets. Platelets are involved in the blood clotting process that stops bleeding.
  • In addition, the spleen acts as a filter, removing old and damaged red blood cells from the blood. It saves useful substances from the cells, such as iron, for recycling.
  • The white pulp contains lymphocytes, a type of white blood cell, as well as other cell types belonging to the immune system. This system protects the body from infection.
  • The white pulp also destroys infectious microbes, including bacteria and viruses, and contributes to the immune system's attack against these invaders.

An Ultrasound Exploration of a Dog's Abdomen

Possible Causes of a Splenic Hematoma in Dogs

There are several possible causes of a splenic hematoma (a hematoma in the spleen) in dogs. These include trauma caused by a blow to the spleen, the existence of a bleeding disorder in the dog, and the presence of a bleeding tumor in the spleen. The tumor may be a hemangioma, which is benign (non-cancerous) or a hemangiosarcoma, which is malignant (cancerous). Some older dogs develop a splenic hematoma for no obvious reason

Based on his symptoms, a physical examination, a blood test, an X-ray, and an ultrasound test, our vet initially thought that a bleeding tumor was responsible for Ryan's discomfort. The tumor could have been either benign or malignant. We were extremely relieved when we were told that the problem was "only" a hematoma caused by blunt force trauma.

In retrospect, we thought that a heavy fall on his side while playing with another dog may have caused Ryan's hematoma. It was important that he received treatment. Blunt force trauma can sometimes be just as deadly as some types of cancer if it's not treated quickly. If the spleen ruptures, very dangerous internal bleeding may occur.

Possible Symptoms of a Splenic Hematoma

The symptoms listed below can be caused by conditions other than a splenic hematoma. Make sure that you see a vet for a diagnosis if your dog exhibits any of the symptoms. The dog's problem may be minor and easily cured, but it may also be more serious and require immediate treatment.

Possible symptoms of a splenic hematoma include:

  • Lethargy
  • Loss of appetite
  • Abdominal pain
  • Abdominal distention
  • Pale gums (due to blood loss)
  • Difficulty breathing (if the spleen is greatly enlarged)

Possible Effects of Blood Loss in the Abdomen

Blood loss from a splenic hematoma may be slow and intermittent, as Ryan experienced. In this case, the blood can sometimes be absorbed by the dog's abdomen.

When Ryan first exhibited symptoms of ill health, we thought that it was time to make a vet appointment soon. Then his behavior returned to normal, and it seemed that he had recovered from whatever was wrong with him. A few days later, the symptoms reappeared and were worse, so this time we took him to the vet immediately. The vet told us that Ryan's symptoms corresponded to the times when his spleen was bleeding. When the bleeding stopped, he felt better.

There is a danger that a hematoma in the spleen could rupture instead of leak. The surgeon said that Ryan's spleen was close to rupturing when he had his splenectomy, so we are very glad that he had the surgery when he did. Severe internal bleeding caused by a ruptured spleen can cause shock, a condition in which there is a rapid and dangerous drop in blood pressure.

Removal of the Spleen, or Splenectomy

The recommended treatment for a splenic hematoma will depend on the dog's condition. In some non-emergency situations, a vet may try treating a dog with compression bandages, intravenous fluids, and careful monitoring. Sometimes the spleen needs to be removed, however. This is especially true in emergency situations.

Unfortunately, as in Ryan's case, it may not be possible to determine the definite cause of an enlarged and bleeding spleen in a dog before surgery or even during surgery. An examination of the spleen by a specialist is required to determine whether cancer cells are present.

My family agreed with the vet's suggestion that the spleen should be removed, even though the swelling and bleeding might have been due to a malignant tumor of the spleen that had already released cancer cells to other areas. Our goal was to give Ryan as long a life as possible. We wanted to get the spleen removed, since that was the immediate emergency, and then consider the next steps once we had a definite diagnosis for the problem. We received the diagnosis of a hematoma caused by blunt force only after the spleen had been removed and examined by a pathologist.

Blood vessels travel to and from the spleen, but a vet who specializes in surgery can expertly disconnect and seal these during a splenectomy and keep bleeding to a minimum. A blood transfusion may still be necessary after the surgery, but Ryan didn't need one. Our vet told us that another common problem immediately after a splenectomy is a heart arrhythmia, which needs to be treated straight away. Ryan was monitored carefully but never experienced this problem. In fact, the vet said that he recovered amazingly well from the surgery.

Laparoscopic Splenectomy

Ryan's spleen was removed in open surgery. In this procedure, a relatively large opening is made in the abdomen in order to reach the spleen and its blood vessels. The opening needs to be closed by stitches afterwards, or in Ryan's case, by staples. This is the most widely used technique for performing a splenectomy in dogs.

A newer surgical technique called a laparoscopic splenectomy involves making several tiny incisions in the abdomen, which are known as ports. Special surgical instruments are inserted through each port. A camera enables the surgeon to see the inside of the abdomen.

Laparoscopic surgery is said to be minimally invasive and is less traumatic for the body than conventional surgical techniques. Not all surgeons have experience in performing this type of surgery, however.

Post-Surgical Care and Living Without a Spleen

It's important that a dog doesn't nibble an incision site and destroy the stitches or staples, which is why Ryan is wearing a cone in two of the photos in this article. The cone is also referred to as an Elizabethan collar or an E-collar.

The vet will probably recommend that the dog avoids climbing stairs for a while and eats frequent small meals rather than a few large ones. The dog won't be allowed to go for walks at first, but will soon be allowed to go for short ones.

Other organs can take over the spleen's functions after a splenectomy, so a dog can live very well without a spleen. For example, like the spleen, the liver breaks down old and damaged red blood cells and recycles some of their components. It increases this activity when the spleen is removed. Although in general humans without a spleen live a normal life, we are more susceptible to certain infections after a splenectomy. According to vets, however, this is not much of a problem in dogs lacking the organ.

Insurance or a Saving Fund for Pet Emergencies

The cost of major veterinary surgery is very expensive. As cute and tempting as a puppy or a dog may be, it's very important to consider the financial future before bringing the dog home. It would be a horrible situation to be unable to afford a treatment that a pet needs in order to be free of pain or to survive.

Pet medical insurance plans are available, but a person needs to be clear about what a plan covers before signing up for it. Another technique for preparing for pet emergencies is to set aside a specific amount of money from every pay period and place it in a separate savings account.

Pets can be dear friends and deserve the best that we can give them. Assessing whether we can afford to take care of a pet and preparing for financial emergencies if we bring an animal into our family are important factors in pet ownership.

Update: In Loving Memory

Unfortunately, I have some sad news to share in this update to my article. Ryan's diagnosis of a hematoma caused by blunt force was wrong, even though it was made by a specialist. He did in fact have cancer. I'm glad that Ryan's spleen was removed, however. He returned to health and had a happy three months of life. Then his symptoms returned, and we discovered that he had multiple tumors in his abdomen.

If your dog is diagnosed with hemangiosarcoma, you should have a detailed discussion with your vet about possible treatments and a prognosis for your pet. It's important to discover and understand as much as you can about your dog's specific condition.

My advice to anyone who has a hematoma or tumor removed from their dog and is told by a specialist that the swelling is benign is to delight in the news and enjoy their pet's renewed health. I would also suggest that they try to give their dog as good a life as possible. If you are ever in this situation, don't wait to take your dog on that special walk that you've been thinking about or to let your dog experience a fun activity that you've been meaning to try. As is true for both dogs and humans, we never know what the future will hold.


  • The spleen in dogs and cats (written by a vet) from WebMD
  • Enlarged spleen in dogs from PetMD
  • Splenic Masses from ACVS (American College of Veterinary Surgeons)

Questions & Answers

Question: How did your vet determine that more tumors were present? My dog had her spleen removed this summer and a non-cancerous tumor was found in it. l am curious to know what symptoms your dog exhibited that made you go back to find other tumors.

Answer: About three months after his spleen was removed, Ryan exhibited nausea, lack of interest in food, weakness, and a swollen abdomen. At times he was giving little cries. The vet used ultrasound to find multiple tumours in his abdomen. Needle aspiration found blood in his abdominal cavity.

Question: I am so sorry to hear about Ryan. My 7 year old male GSD just got a splenectomy. How was Ryan's quality of life after the surgery?

Answer: Ryan's quality of life after the surgery was good until the true nature of his problem arose. As I say in the article, he seemed healthy and happy for three months after the surgery. He recovered from the operation well and seemed to return to normal until his multiple tumours created problems. His condition was complicated by the fact that he had cancer that had spread. The splenectomy was helpful for him, but because of his specific situation, it wasn't a long-term solution for his problem. I hope your dog recovers well.

© 2014 Linda Crampton

Linda Crampton (author) from British Columbia, Canada on August 31, 2020:

That’s entirely up to you and your particular situation. All I can say is that veterinarians are generally highly trained and skilled individuals. I am guessing (but don’t know) that some conditions might be harder to diagnose, recognize, or treat in particular animals or in particular cases than in others. I hope your grandpup enjoys renewed health and a long life.

Barbara Knowles on August 31, 2020:

My Grandpup just had a Splenectomy, His parents got the results today that it was just a hematoma no cancer found. The vet did a biopsy On his liver also no cancer found. Since you found out three months later that it was cancer do I trust this diagnosis?

Linda Crampton (author) from British Columbia, Canada on April 15, 2020:

It's good that you took your dog to the vet. I hope she recovers quickly.

Debra on April 15, 2020:

My dog is 11 yrs old and had a hematoma on her ear so she started not being able to walk so we took to the vet and they did surgery all she is doing is laying down and just started drinking water again

Linda Crampton (author) from British Columbia, Canada on May 09, 2019:

I can't answer this, Jane. As I say in the article, I'm a pet owner but not a veterinarian. You need to contact your vet to ask him or her about your dog's situation. Best wishes to you and your dog.

Jane Speller on May 09, 2019:

My poodle cross has just undergone a splenectomy which revealed a benign tumour, Her recovery has been slow and she is showing low red cell count and vet has recommended a sample of bone marrow. What could this mean?

Linda Crampton (author) from British Columbia, Canada on November 18, 2018:

Thank you for the comment, Anne. I am so sorry that you and your dog are experiencing this situation. I hope everything works out as well as possible and that you have a lot of time left with a dog who feels fine. Best wishes to you both.

Anne on November 17, 2018:

Thank you Linda, your article was very helpful. It is generous of you to share such a painful experience, you must miss Ryan very much. My precious Terrier underwent an emergency splenectomy 2 days ago, due to a large mass. Her condition last week was exactly how you described with Ryan, one day hiding under the table and obviously unwell, the next fine. Luckily my vet performed an ultrasound and discovered the unexpected mass which had caused the spleen to rupture. I now await test results of the tumour. Your article has informed me of what to expect, what questions to raise with the vet, and what symptoms to look out for especially in regards to metastasis. It is devastating, thank you for describing your journey.

Linda Crampton (author) from British Columbia, Canada on November 04, 2018:

Best wishes to you and your dog, Jennifer. I know the situation is very worrying, but I hope the outcome is good.

Jennifer Cummins on November 04, 2018:

Thank you so much for this article. My much loved Irish Terrier has been diagnosed with two tumours in his spleen. We are about to fix a date for a splenectomy and hopeful that it is non-malignant. Your article has been so informative and has helped me in this nightmare situation.

Linda Crampton (author) from British Columbia, Canada on November 28, 2014:

Thank you so much for the visit and the comment, thougtforce. I appreciate your kindness.

Christina Lornemark from Sweden on November 28, 2014:

I am so sorry to read about Ryan, and I know you miss him so much. Such a beautiful dog and I personally feel strongly for large breeds. This hub is very interesting and you explain everything so well. It is a very useful article.

Linda Crampton (author) from British Columbia, Canada on November 25, 2014:

Thank you very much, Margaret. I appreciate your visit and your kind comment a great deal.

Margaret Schindel from Massachusetts on November 25, 2014:

I'm so terribly sorry to hear about Ryan's misdiagnosis and recent passing. This is a wonderful article that will help save many other dogs' lives and, as such, is a beautiful tribute to your bel0ved Ryan.

Linda Crampton (author) from British Columbia, Canada on November 25, 2014:

Thank you so much for the kind comment, Martie. I appreciate it very much. Your last statement is very true. We were told that the pathologist analyzing Ryan's spleen was an expert at diagnosis, but it turns out that our vet was more accurate about Ryan's problem than the pathologist.

Martie Coetser from South Africa on November 25, 2014:

For some reason I have never done any research on the spleen, so I found this hub extremely interesting.

But oh, the unexpected sad news about Ryan pulled my tears. I am so sorry, Linda. So true, we will never know the future, and we have to accept the fact that doctors and vets don't have supreme knowledge and wisdom.

Linda Crampton (author) from British Columbia, Canada on June 25, 2014:

Hi, Peggy. Thank you very much for the comment and the pin! Yes, we were so relieved that Ryan didn't have cancer and that we got him to surgery on time. He's part of our family!

Peggy Woods from Houston, Texas on June 25, 2014:

So glad that your Ryan is doing well and that the spleenectomy resolved his problem with no further treatment necessary such as would have happened had there been a diagnosis of cancer. He is a handsome boy! Pet insurance policies can certainly help defray expenses! Pinning to my dogs board.

Linda Crampton (author) from British Columbia, Canada on June 22, 2014:

Thank you very much for the comment, Thelma! Ryan's illness was a scary time for us, but luckily his experience had a happy ending. I hope your Sunday is lovely, too!

Thelma Alberts from Germany and Philippines on June 22, 2014:

I´m glad that Ryan is fine now. That must be a scary moment for you and your dog. I have never heard of this sickness. I hope it will not happen to my dog. Thanks for sharing this very well written and informative hub. Have a lovely sunday!

Linda Crampton (author) from British Columbia, Canada on June 18, 2014:

Thank you for the visit and the comment, Dianna. I'm glad that your sister is doing well without her spleen!

Dianna Mendez on June 18, 2014:

Your dogs are so adorable! My sister had her spleen removed years ago and she is doing quite well. I guess this proves your facts on this article. Thanks for the information which was quite interesting to read.

Linda Crampton (author) from British Columbia, Canada on June 14, 2014:

Thank you very much for the comment, Peg. I'm so sorry about Dolly. It's horrible when a pet has an illness that can't be treated. Dogs can be such wonderful family members.

Peg Cole from Northeast of Dallas, Texas on June 13, 2014:

Oh I'm so glad to hear that Ryan is doing okay. He is so cute! Your pictures of him are adorable and the explanation of the trouble he had was thorough and informative.

Our vet told us he sees about 3 cases a month involving spleen issues. In fact, our 14 year old Dolly was diagnosed with a tumor on her spleen that was inoperable. We were grateful that we'd had so many years to enjoy having her as part of our family, but it's never enough time.

Linda Crampton (author) from British Columbia, Canada on June 10, 2014:

Thank you very much, Mel. I appreciate your visit. Yes, I'm glad to say that Ryan is almost completely back to normal now and is happy again.

Mel Carriere from Snowbound and down in Northern Colorado on June 10, 2014:

So glad your pup is doing well. He looks like an amicable fellow. You are absolutely right that dogs deserve the best medical care available, which is why I don't have one, because I don't think I could dedicate the time or resources. Great hub!

Linda Crampton (author) from British Columbia, Canada on June 09, 2014:

Thanks, Deb. Yes, a pet is definitely a long term commitment. It we can afford the expenses, though, pets can be wonderful companions!

Deb Hirt from Stillwater, OK on June 09, 2014:

Glad to hear that Ryan is happy and well again. A et is a long term commitment, and I have had my share of expenses, too, in that regard. However, they are a part of our lives and must be well cared for.

Linda Crampton (author) from British Columbia, Canada on May 29, 2014:

I'm very glad that your dog's leg problems were solved, Audrey! It's so hard to see our pets in discomfort or pain. Thanks for the visit. I appreciate your comment.

Audrey Howitt from California on May 29, 2014:

So glad that Ryan is ok! Our dog had 2 leg surgeries before we got wise and bought pet insurance--She is a happy and healthy dog now and I am glad--Pups are wonderful!

Linda Crampton (author) from British Columbia, Canada on May 29, 2014:

Hi, Heidi. I'm sorry about your experience with cancer in one of your dogs. I've experienced the same heartbreak. I've also experienced receiving horrendous vet bills of thousands of dollars! Surgery - especially emergency surgery on a big dog - is very expensive. As you say, though, the investment is worth it for a believed pet! Thank you very much for the comment and all the votes.

Heidi Thorne from Chicago Area on May 29, 2014:

You make excellent points about the investment that pets can be! After a $5K weekend vet bill for our first dog over 20 years ago, we've always gotten pet insurance for them. It's really helped with so many issues and cancer riders are available (which, unfortunately, I've had to use).

But the investment is so worth it. Your pictures of Ryan and Misha are just adorable! Voted up, useful, beautiful and interesting!

Linda Crampton (author) from British Columbia, Canada on May 29, 2014:

Thank you for the lovely comment, Cynthia! I appreciate your visit.

CMHypno from Other Side of the Sun on May 29, 2014:

As usual I am in awe at the depth of your knowledge Alicia. I hope Ryan has made a very speedy recovery and can look forward to many happy years with you and your family.

Linda Crampton (author) from British Columbia, Canada on May 28, 2014:

I'm glad that your dog is doing so well, Bill. I hope she stays healthy and lives for a long time. Thank you very much for the comment.

Bill De Giulio from Massachusetts on May 28, 2014:

Hi Linda. So glad to hear that Ryan is okay and doing well. They are both beautiful. I was not aware of this potential issue with the spleen so this is good info to know. Our 12 year old shih tzu has not had any problems with her spleen but has had other issues over the years. At 12 she is in remarkably good condition and should have a long life ahead of her.

Linda Crampton (author) from British Columbia, Canada on May 28, 2014:

Hi, Liz. I'm glad that your dog recovered, too! Thank you very much for the visit and the comment.

Elizabeth Parker from Las Vegas, NV on May 28, 2014:

Thanks for posting this. My dog had an aural hematoma, but I never even thought of it for the spleen! I'm glad Ryan is okay. He is adorable!

Linda Crampton (author) from British Columbia, Canada on May 27, 2014:

Thank you very much for the comment, Flourish. We have three cats, but so far neither the cats nor Misha (the black lab) have had any major health problems. Ryan's been the unlucky one! I love the information about the sign in your vet's office.

Linda Crampton (author) from British Columbia, Canada on May 27, 2014:

Thank you, Rebecca. (I think that Ryan's a cutie, too! )

FlourishAnyway from USA on May 27, 2014:

Linda - Ryan is adorable, from his puppy photos to his adult photos. I didn't know much about spleen problems in dogs as I have cats with just about every other medical situation, so I learned something from reading his story. I home he has a long happy life. The photo of Ryan in a cone reminded me of a sign in my vet's office: "It's all fun and games 'til someone ends up in a cone."

Rebecca Mealey from Northeastern Georgia, USA on May 27, 2014:

Thanks. Good info to know for dog owners. Ryan sure is a cutie!

Linda Crampton (author) from British Columbia, Canada on May 27, 2014:

Hi, Nell. Thanks for the comment, the vote and the share! I'm very relieved that Ryan is okay, too. It was a tense time when we were waiting for the test results.

Nell Rose from England on May 27, 2014:

Hi Alicia, I am so glad that your dog is fine now, what a nightmare! but its something I would never have thought of, so this is really useful for those dog owners who may find something is wrong but not sure exactly what, the best thing is to take them straight to the vets as you said, that must have been a scary moment there, but I am glad he is okay now, voted up and shared! nell

Linda Crampton (author) from British Columbia, Canada on May 27, 2014:

Thank you very much, Bill. I appreciate your kind comment!

Bill Holland from Olympia, WA on May 27, 2014:

The dogs were adorable and the information right on! Great article and very interesting.

Linda Crampton (author) from British Columbia, Canada on May 27, 2014:

Thank you very much for the visit and the comment, DDE!

Devika Primić from Dubrovnik, Croatia on May 27, 2014:

Hi AliciaC what an interesting hub!

I so enjoyed reading and learning about the spleen. The dog has to go to through so many changes and symptoms. You kept me reading on and so contently. A well-planned and informed hub.Voted up!

Spleen Functions, Hematoma, and Removal (Splenectomy) in Dogs - pets

In animals with splenic torsion, the blood vessels to the spleen are twisted into a pedicle that contains the mesentery and vessels. Do not untwist the spleen since this will allow cellular breakdown products, thrombi, and other toxic substances to be released into circulation.(1) Ligate the entire vascular pedicle with full and transfixing ligatures and remove the spleen.

After removal of the spleen, check all ligated vessels for lack of persistent hemorrhage and then close the abdomen routinely.

Postoperative Care and Complications

Maintain supportive care immediately after surgery consisting of intravenous fluids, analgesics and monitoring of vital signs. If preoperative or intraoperative blood loss was excessive monitor the animal’s PCV postoperatively and consider blood transfusion if the PCV drops below 20. With appropriate care most dogs will recover from splenectomy quickly with many being discharged from the hospital the day after surgery.

The most common complication associated with splenectomy is hemorrhage. Other potential complications include pancreatitis, cardiac arrhythmias, and postoperative pain.

The prognosis for dogs undergoing splenectomy varies depending on the splenic disease. Dogs and cats with splenic trauma, splenic torsion, or benign neoplasia have a good prognosis assuming they survive the perioperative period. In contrast, animals with malignant neoplasia, most commonly hemangiosarcoma, have a poor prognosis due to the tendency for metastasis of the primary tumor.(2)


1. Richter MC. Spleen, in Veterinary Surgery: Small Animal, eds. KM Tobias, SA Johnston, Elsevier, St. Louis, 2012, pg. 1341.
2. Spangler WL1, Kass PH. Pathologic factors affecting postsplenectomy survival in dogs. J Vet Intern Med. 1997 May-Jun11(3):166-71.

Increased Infection Risk

What Causes Elevated Platelet Counts?

Without a spleen, serious infections can result following what would normally be minor illnesses. The risk can be lowered by the administration of vaccines for pneumonia, meningitis and influenza prior to surgical removal of the spleen, if possible, or soon after. The risk of developing serious infections is much greater in children than adults, according to APSA. Usually it will present within two years of splenectomy, but infection can occur at any time. It is important to keep vaccines current.

The prophylactic use of antibiotics is advised by many physicians, particularly for children until they reach adulthood. But an increase in drug-resistant pathogens makes this approach controversial. All patients should be educated to avoid unnecessary risks and to take prompt action at the first sign of illness.

  • Without a spleen, serious infections can result following what would normally be minor illnesses.
  • The risk can be lowered by the administration of vaccines for pneumonia, meningitis and influenza prior to surgical removal of the spleen, if possible, or soon after.

Spleen Functions, Hematoma, and Removal (Splenectomy) in Dogs - pets


(original graphic by


The spleen is an oblong organ (some would say it is tongue-shaped) seated just below the stomach. Its consistency is similar to that of the liver. While one can live perfectly well without a spleen, the spleen does provide some helpful services to the body.

(original graphic by

    The spleen contains lots of long winding narrow blood vessels full of hair-pin turns for circulating red blood cells to make. This means that there are a lot of red blood cells working their way gradually through the spleen at any given time effectively making the spleen a storage area for blood. If one has a severe hemorrhage and needs extra blood, the involuntary muscles of the spleen contract, squirting forth a fresh supply of blood. The spleen provides nature’s blood transfusion, if you will.

Older red blood cells become more brittle than their younger counterparts. As they attempt the tortuous route through the spleen, many older red cells do not make it out the other side. These cells rupture trying to make the tight turns and their iron is captured and recycled by the spleen. The spleen thus helps remove old red blood cells from the circulation, sort of a clean-up function.

The spleen also performs a function called “pitting” where it is able to bite off sections of the red blood cells passing through. The areas of the red blood cell that the spleen has designated for it to bite off or “pit” have been marked by the immune system. In this way the spleen can remove red blood cell parasites from the circulating red blood cells, helping keep cells functioning that otherwise might become irreparably damaged if their infection is allowed to persist. Sometimes entire red cells are removed from the circulation in this way thus preventing the spread of the red cell parasite inside. This sounds like a good thing but it can get out of hand. For example, in Feline Infectious Anemia, the spleen commonly removes so many red blood cell portions that the infection is difficult to detect plus the patient becomes dangerously anemic (not from the actual parasite but from the spleen removing large numbers of infected red blood cells). In severe cases of this condition, the spleen may have to be removed.

    The above functions take place in what is called the “red pulp” of the spleen. The spleen also contains what is called “white pulp.” The white pulp is essentially part of the lymphatic system, sort of like a lymph node. It serves the same functions as a lymph node but is connected through the circulatory system. Lymph nodes are centers of activity for the immune system, especially antibody producing lymphocytes. Material from the local area of the body drains to the lymph node via the lymph vessels and the lymphocytes may or may not become stimulated into reacting depending on what sort of material is present. A reactive lymph node enlarges (the obvious example is the submandibular nodes that swell when one has a sore throat). The white pulp of the spleen sees material from the circulatory system rather than material from the local lymphatics. Lymphocytes circulate through the splenic white pulp just as they do through the lymphatic vessels, carrying messages involved in the war against body invaders (bacteria, viruses etc.)

    There are several reasons why the spleen might need to come out. In dogs, by far the main reason is a growth or mass on the spleen which has broken open and started bleeding and much of the discussion below regards this scenario. Other reasons to remove the spleen involve curtailing the pitting function reviewed above. In immune-mediated anemia, the spleen is removing too many red blood cells and the patient is suffering for it. Usually medication is used to suppress the immune-system but sometimes this is inadequate and the spleen must come out. Similarly, animals being considered as blood donors sometimes have their spleens removed to curtail the pitting function and facilitate the detection of blood parasites that might preclude use as a blood donor.

    Additional reasons to remove the spleen include infiltration by cancer. In particular, there is a form of mast cell cancer in cats which is largely limited to the spleen and removing the spleen can be provide a long remission or even cure. Sometimes the spleen is ruptured in a trauma and must be removed to control the bleeding. For the most part, spleens are removed because they have grown a mass which has started to bleed so our discussion will begin here.


    Most spleens are removed because they have grown a tumor. Tumors can be benign (like the red pulp hemangioma) or malignant (like the red pulp hemangiosarcoma, white pulp mast cell tumors, or white pulp lymphosarcoma). In dogs, most splenic masses are either hemangiomas or hemangiosarcomas while in the cat they are usually either mast cell tumors or lymphosarcomas.


    Both these tumors arise from the blood vessels of the red pulp and amount to a bunch of wildly proliferating abnormal blood vessels. Eventually the growth ruptures and the spleen bleeds. When a vascular organ like the spleen bleeds, a life-threatening blood loss can result.

    • Usually the patient is suddenly weak.
    • The patient may be obviously cold.
    • If one looks at the color of the gums, the patient will be pale in color.
    • If the bleed stops on its own before it has gone too far, the patient may be dramatically better the next day or even a few hours later.

    Unfortunately, the splenic mass is certain to bleed again and if the spleen is not removed, eventually the patient will bleed to death.

    If the splenic tumor is benign, removing the spleen is curative provided that the patient has not lost too much blood to survive the surgery. Ideally, the splenic mass is detected before it has ever bled and the spleen is removed at a time when the mass is not actively bleeding. Of course, if the splenic mass IS actively bleeding and cannot be stopped with pressure wraps, removing the spleen becomes an emergency surgery it is not appropriate to try to wait until the bleeding has stopped. Expect blood transfusions to be necessary before, during, and possibly after surgery.

    If the splenic tumor is a malignant hemangiosarcoma, the spleen can still be removed to control the bleeding but the problem is that hemangiosarcoma is an aggressive cancer. With the removal of the spleen and primary tumor, the patient is probably spared death by bleeding to death only to eventually succumb to cancer. Since the decision to go to surgery often hinges on whether or not the tumor is malignant, some effort should be made to make this determination if delaying the surgery can be safely done. Chest radiographs and abdominal ultrasound are performed to look for evidence of tumor spread.

    If there is evidence of tumor spread: this means the tumor is malignant and best control will entail both removal of the spleen and chemotherapy follow up. Many people opt for euthanasia at this point though newer drugs have held promise. Please see the hemangiosarcoma page for more details.

    If there is no evidence of tumor spread: it may be possible to effect a permanent cure by removing the spleen though lack of visible tumor spread does not mean the tumor is benign. An actual piece of spleen tissue for biopsy will be needed to settle the question of malignancy.


    Radiograph showing an enlarged spleen (circled).
    (original graphic by

    There are several ways to detect a splenic mass. The first way, is by physical examination. A large firm mass in the area of the spleen may be palpable during a routine physical examination. From there, radiographs are taken of the belly to see if the mass appears to be on the spleen and radiographs of the chest are taken to see if there is evidence of cancer spread there. Based on these findings (plus basic blood work) a decision for or against spleen removal can be made. Unfortunately, many large dogs are simply too well muscled for splenic masses to be detected in this way.

    Another method of detecting a splenic tumor comes on the basic blood panel. An unexplained “responsive anemia” is discovered. A responsive anemia is one typical of bleeding (as opposed to an anemia of chronic disease where red blood cells simply are inadequately produced.) An older large breed dog with an unexplained bleed is highly suggestive of a splenic tumor. The next step would be radiographs to see if a mass is apparent followed by chest radiographs for tumor spread as above. These findings on the blood panel are especially suggestive of a splenic mass if there has been a history of sudden weakness or collapse typical of a recent bleed. Splenic tumors tend to bleed intermittently (and usually insignificantly) prior to a large bleed that produced obvious symptoms. These smaller bleeds are generally enough to alter the blood panel. If blood work is suggestive of a splenic mass, radiographs can be taken to confirm the presence of the mass.

    It can be difficult to determine from the radiograph if the mass is coming from the liver or from the spleen.


    Unfortunately, eventually the dog will have a bleed from which he cannot recover. If you think your dog is having a bleed at home, you can apply an ace bandage around the belly in a snug manner to essentially apply pressure to the bleed. This is surprisingly effective and may stave off the inevitable temporarily or until you can get your dog to an emergency hospital for more definitive support such as a blood transfusion. There is a Chinese herb called Yunnan Baiyo which can assist in blood clotting and may be helpful in minimizing the severity of future bleeds.

    Chemotherapy may still be an option even if the spleen and its malignant tumor are left behind. A newer approach to chemotherapy, called "metronomic" chemotherapy, focuses on eliminating the blood supply of the tumor rather than on killing the tumor directly. Lower doses of chemotherapy drugs are used which leads to far less potential for side effects. If this is something you are considering, it will be necessary to consult an oncologist for the most up to date information.


    We have already mentioned the splenic mass as well as excessive red blood cell removal by the spleen as reasons for splenectomy. There are some other situations where splenectomy may be needed:

      In this condition, the stomach bloats with gas and twists on its axis effectively cutting off its circulation. This is a huge emergency usually requiring surgery. The issue with the spleen is that the spleen rides just below the stomach so that when the stomach twists, the spleen twists along with it. Frequently the spleen must be removed or partly removed.
      If the patient suffers blunt trauma to the abdomen such as getting kicked by livestock or being hit by a car, the spleen may rupture and dangerously bleed. If a tear in the spleen is small, it may be repaired (sewn together) but if the rupture is severe, it may be easiest to simply remove the whole spleen.


    When a dog with a splenic mass is going to have its spleen removed (“splenectomy”) there are some issues to understand.

    • The spleen may begin bleeding at any time up until it is actually removed. If this occurs, blood transfusion is likely going to be needed (either with artificial blood or whole blood, depending on what is available). It is possible that multiple transfusions will be needed. A parameter called the “PCV” (“packed cell volume”) will be monitored to make sure the amount of circulating red blood cells does not fall dangerously low. If one is lucky, the spleen will not be bleeding at any time during surgery. Some patients must receive blood transfusions prior to splenectomy to insure they have a reserve of red blood cells in case of surgical bleeding.


    The spleen is supplied by numerous blood vessels which must
    be ligated or sealed in order for the spleen to be removed.
    Be prepared for blood transfusion(s) to be needed.

    Splenic Masses

    The term "ACVS Diplomate" refers to a veterinarian who has been board certified in veterinary surgery. Only veterinarians who have successfully completed the certification requirements of the ACVS are Diplomates of the American College of Veterinary Surgeons and have earned the right to be called specialists in veterinary surgery.

    Your ACVS board-certified veterinary surgeon completed a three-year residency program, met specific training and caseload requirements, performed research and had research published. This process was supervised by ACVS Diplomates, ensuring consistency in training and adherence to high standards. After completing the residency program, the individual passed a rigorous examination. Only then did your veterinary surgeon earn the title of ACVS Diplomate.

    Splenic hematoma and nodular hyperplasia are the most common non-cancerous lesions found in the spleen and account for 20–41% of all splenic lesions. They are benign nodules/masses of clotted blood. Surgical removal is curative.

    Hemangiosarcoma is a common malignant tumor of the spleen usually seen in older dogs (8–10 years of age). Any large breed dog appears to be at an increased risk especially German Shepherds, Golden Retrievers, Labradors, and Poodles.

    Signs associated with splenic masses can be subtle and include weakness or may be more obvious e.g. collapse and sudden death if the mass ruptures and bleeds internally. Mucous membranes, such as the gums, may be pale and heart and respiratory rates can be increased. Other signs can include

    • abdominal distension
    • weight loss
    • inappetence
    • fainting or weakness

    Your primary-care veterinarian may run several tests to obtain a presumptive diagnosis and to prepare for surgery. These may include blood tests, urinalysis, a clotting profile, examination of fluid obtained from the abdomen, and chest and abdominal radiographs (Figure 1). Abdominal ultrasound is another useful method to identify and characterize masses in the abdomen as well as look for free fluid or blood. Echocardiography (ultrasound of the heart) may be recommended as some dogs may have tumor spread to the heart.

    Surgery is the primary method of treatment for dogs with splenic masses. This involves removal of the spleen (splenectomy). Removal of the spleen is preferred to a biopsy as it serves as both a diagnostic and therapeutic procedure (Figure 2). Patients are stabilized prior to surgery. This may require fluid therapy or a blood transfusion and intensive care monitoring.

    The final diagnosis relies on microscopic examination the mass after surgical removal. Splenic hematomas and hemangiomas as well as other benign disease can have a similar clinical presentation and must be differentiated from hemangiosarcoma. Up to 2/3 of dogs with splenic masses have a malignant tumor (2/3 of these are hemangiosarcoma). Dogs with a ruptured splenic mass requiring a blood transfusion are more likely to be diagnosed with hemangiosarcoma. The remaining patients have benign masses that are effectively treated with splenectomy.

    Your dog’s activity should be restricted to short leash walks only during the first two weeks of healing. Your dog may need to wear an E-collar or tee shirt to prevent self-trauma to the surgical site.

    Benign splenic masses are effectively cured with surgery. Unfortunately, survival times with surgery alone for dogs with hemangiosarcoma may be 2–3 months or less. One year survival is less than 10%. Ultimately dogs die from metastatic disease. Chemotherapy may increase survival times up to 6–8 months.

    Complications that may be associated with surgery include hemorrhage (ongoing bleeding), cardiac arrhythmias (irregular heart rhythm), and pancreatitis (often manifested by vomiting). An ECG to look for arrhythmias is recommended after surgery. While this may require treatment, most arrhythmias resolve within 24–48 hours.

    Photos provided courtesy of Elizabeth Hardie, DVM, PhD, Diplomate ACVS.

    Watch the video: Removing The Spleen - What Is A Splenectomy? (July 2021).