What Does the Dog’s Spleen Do? Key Functions Explained
The spleen is a vital organ nestled just below the stomach in dogs, playing several important roles related to blood and the immune system. While some dogs may require spleen removal surgery due to cancerous tumours or other issues, many live healthy lives afterward without complications. Certain breeds, such as the golden retriever, are more prone to spleen problems.
The fact that dogs can live without their spleen sometimes leads to confusion, with owners mistakenly thinking it is an unnecessary organ, similar to how humans regard the appendix or adenoids. However, the spleen’s functions are both important and unique. This article explores what the spleen does when healthy, why its removal is sometimes necessary, and how dogs adapt and thrive post-splenectomy.
What Does the Dog’s Spleen Do?
The dog’s spleen serves as a multifunctional organ with key roles:
- Blood Reservoir and Storage: The spleen stores red blood cells and platelets. When the dog experiences blood loss or needs extra oxygen delivery, the spleen contracts to release stored red blood cells back into circulation, helping recovery.
- Removal of Aged and Damaged Red Blood Cells: As red blood cells age, the spleen filters and breaks them down, recycling iron and other components to support new blood cell production.
- Immune System Support: The spleen filters harmful pathogens, blood cell parasites, and foreign particles from the bloodstream. Through a process called "pitting," it removes disease-causing sections from red blood cells, reducing the need to destroy entire cells.
- Contribution to Hematopoiesis: Beyond storage and filtering, the spleen is involved in producing certain blood cells, acting as a secondary site for blood cell formation outside of bone marrow.
- Lymphatic System Backup: The spleen helps stimulate lymphocytes—the immune cells that produce antibodies—especially if lymph nodes have not already activated an immune response, thus aiding in infection control.
Altogether, the spleen aids in maintaining healthy blood composition and provides crucial immune defence, reducing risk from infections and blood parasites.
How Can Dogs Live Without a Spleen?
Despite the important roles the spleen plays, dogs can usually live normal lives without it due to the body’s ability to compensate:
- Backup Function: Many of the spleen’s tasks are supportive or secondary. For example, the spleen only releases stored red blood cells during emergencies like anaemia or severe blood loss, which many dogs never experience.
- Other Organs Assist: Organs such as the liver can take over certain functions, like storing iron.
- Immune System Compensation: The immune system has multiple layers of defence. Lymph nodes and other organs largely maintain immunity even if the spleen is removed.
While splenectomy (removal of the spleen) is a serious procedure, it is usually only performed when necessary, such as with splenic tumours, which are a common concern in older dogs. Your vet will always explore alternative treatments first. If removal is necessary, with proper veterinary care and monitoring, your dog can live a full and healthy life.
Understanding your dog's spleen and its functions can help you appreciate the resilience of canine health and the importance of responsible veterinary care.
