The spleen is a tongue-shaped organ in the abdomen that filters the blood by removing old red blood cells from the bloodstream, storing iron, and removing bacterial pathogens. In addition, the spleen stores blood for emergency situations, such as a hemorrhagic shock.
A splenic tumor is a mass or lump within the spleen. Such tumors tend to affect older dogs of 8 to 10 years of age, with German Shepherds, Golden Retrievers, Labrador Retrievers, and Poodles among the breeds most prone to the cancers that cause splenic masses.
Of all splenic masses, two-thirds are malignant, meaning they are cancerous and can spread to other parts of the body. Of the malignant splenic tumors, two-thirds are hemangiosarcoma, which is a particularly aggressive tumor that originates from blood vessels. Because the spleen is such a blood-enriched organ, it is generally one of the first places for this cancer to appear, eventually spreading to the liver, lungs, heart, brain, spinal cord, skin, and muscles. Other, less common malignant tumors that affect the spleen include lymphosarcoma, leiomyosarcoma, fibrosarcoma, and mast cell tumors.
Benign masses in the spleen are most commonly hematomas, or bruises. If your pet presents with a splenic mass and internal bleeding, there is a 76% risk of it being a malignant splenic tumor and a 70% risk of that tumor being the result of hemangiosarcoma.
Whenever your pet is showing signs of a health issue your first step is to contact your primary care veterinarian. If it is indicated that your pet may have a splenic tumor or another serious condition, a veterinary specialist is available at an ExpertVet certified hospital.
If your dog has a splenic mass, you probably won’t notice any difference in your pet until the mass actually ruptures, which can happen during exercise or rough motion or for no reason at all. Because most splenic masses are caused by a cancer of the blood vessels, the blood vessels – and therefore mass walls – are weak and prone to breakage.
You will know, however, when a splenic mass ruptures because it can be painful for your pet. When a mass ruptures, it causes internal bleeding and is accompanied by acute weakness or collapse, pale gums, and a rapid heart rate. As the internal bleeding progresses, the abdomen will fill with blood, resulting in significant distress for your pet that might include crying out, panting, pacing, or lying still. The hemorrhaging caused by a ruptured splenic mass is an emergency situation, and should be addressed as such with immediate veterinary attention.