Topography
The dorsal extremity (head) lies under the last ribs, between the gastric fundus and the left kidney, and is the most fixed part. The body and ventral extremity follow the greater curvature of the stomach and, being mobile, shift with gastric filling. In the cat it is relatively smaller and narrower than in the dog.
Structure
Capsule and trabeculae with smooth muscle, white pulp (lymphoid tissue around the arterioles) and red pulp. The feline spleen is non-sinusal: it lacks the true venous sinuses found in the dog's spleen.
Clinical relevance
- Radiography: on the lateral view the normal feline spleen is barely visible; on the ventrodorsal view its head appears as a triangle lateral to the fundus. A clearly visible spleen on the lateral view suggests splenomegaly.
- Splenic mast cell tumour: one of the most common causes of diffuse splenomegaly in the cat; splenectomy is the treatment of choice.
- Lymphoma: the other common splenic neoplasm. Haemangiosarcoma is much less common than in the dog.
- Other causes of splenomegaly: extramedullary haematopoiesis, haemoplasmosis (Mycoplasma haemofelis) and feline infectious peritonitis. Ultrasound-guided fine-needle aspiration guides the diagnosis.
3D model
Segmentation from the CT of a cat (pixelbeaker model), simplified and registered to the atlas skeleton.