The spleen is present in the left-forward part of the abdomen near the stomach in dogs. The size of surrounding organs and the stomach affects its location. It is a dark, red-colored organ which is relatively big in size and is the largest secondary lymphoid organ in a dog's body. It is covered by a fibrous tissue which is tough and hard. The pedicle is the place where the blood vessels enter and exit the spleen.
Functions of the Spleen in Dogs
- The spleen helps in the smooth functioning of the lymph and the immune system. The white pulp present in it consists of immune response cells which assist the immune system to fight infections.
- Another function is that it assists the blood systems in the filtration of blood. The marginal zone helps in filtration by separating the red and white pulp. This organ has the capability of eliminating or removing the abnormal and old blood cells or particles present in the blood. It also has the ability of trapping the foreign particles and bacteria from the blood circulation, thus filtering the blood.
- The red pulp helps in red blood cell formation and also in trapping and storing the immune proteins called antigens. This function of the spleen is termed as hematopoiesis
- This organ also helps in the storage of blood, which is capable of contracting with the increase in the metabolic demands. While it does not perform the function of contraction, it relaxes and serves the role of a blood reservoir and releases more red blood cells into the bloodstream.
Spleen Diseases in Dogs
An enlarged spleen can signify a disease which can have an effect on the dog's immune system. It can also give rise to massive production of red blood cells and can also be a reason for anemia. Bleeding disorders, tumors, and blood clots occur due to a spleen disease called hematoma. Hematoma means collection of blood. Twisting of the spleen is also a commonly-observed disease in large and deep-chested dogs, which can cause health problems.
Twisting can cause stomach dilation and torsion. Benign tumors like hemangiomas can also affect this organ. Malignant and cancerous tumors like canine hemangiosarcoma affects middle-aged and older dogs. This is a severe disease which should be treated as soon as possible, as it can lead to death. Apart from hemangiosarcoma, malignant tumors like lymphosarcoma, mast cell tumors (MCT), and multiple myeloma can also attack the dog's spleen.
In order to find the underlying problem of the disease, exploratory surgery of the abdomen might be required. If despite the surgery the problem still remains unknown, the spleen tissue will be required for diagnosis. However, most of the time, the illness can be identified by conducting an abdominal ultrasound medical examination or a complete blood count test. Bone marrow aspiration, microscopic examination of the blood, and abdominal radiographs may also be helpful for the same.
At times, if the condition goes out of hand and the growth on the spleen bursts leading to internal bleeding, the vet will recommend a procedure known as a splenectomy, which entails complete removal of the spleen. The growth is then tested to know whether it is malignant or benign and the follow-up is done accordingly. However, most dogs are said to survive only for a few months after this surgery if the tumor turns out to be malignant. There is also a high chance of metastatic diseases affecting the dog. This, however, depends on the individual dog as many have been known to pull through the surgery.
If you find anything wrong with your dog, take him/her to the vet immediately. Also, regular health checks should be undertaken to ensure that your dog is healthy. After all, prevention is better than cure.