Note for Pet Owners:

This information is provided by Provet for educational purposes only.

You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

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Cancer of the spleen is frequently seen in large breed dogs and by far the most common type of cancer is hemangiosarcoma, a malignant form of cancer that frequently spreads to other organ systems.

Other, less common  forms of cancer of the spleen include :

  • Hemangiomas (benign)
  • Leiomyosarcomas
  • Fibrosarcomas
  • Non-neoplastic hematomas also occur

Definitive diagnosis can only be made bby histopathological examination of a removed spleen, or biopsy of lesions. Survival times are much better for the non-hemangiosarcoma tumours.

Hemangiosarcoma is a cancer of the vascular endothelium.

Breed Occurrence
Cancer of the spleen can occur in any dog - but it is most frequently seen in large breeds or cross-breeds. The German Shepherd Dog is at increased risk  to develop hemangiosarcoma of the spleen compared to other breeds, and it occurs most frequently in dogs aged 8-13 years of age.

The most common initial signs are associated with internal rupture of the tumour leading to internal hemorrhage causing

  • Sudden onset weakness and collapse
  • Shock
  • Anemia
  • Abdominal distension

Metastatic spread throughout the abdomen is possible if the tumour has ruptured. Otherwise the liver is the  most common organ to which hemangiosarcoma spreads.

If the spleen is not removed repeated hemorrhages are likely, and the risk of spread increases greatly.

Splenic hemangiosarcomas can usually be easily felt on abdominal palpation, They are also easily identified as medium to large mid-ventral abdominal masses on radiography and ultrasound examinations.

Removal of the spleen (splenectomy) is the treatment of choice. Severely anemic patients require intravenous fluid support, and very large tumours can put pressure on vital organs such as the major blood vessels so positioning during surgery  (lie the animal slightly tilted to one side so the mass does not compress the caudal vena cava) is important to minimise complications due to pressure

According to published papers the mean survival time in dogs with hemangiosarcom is only about 3-4 months, however there are cases that have survived 1 year or more following surgery. This is most likely if the diagnosis is made at the time of the first hemorrhage.

Long term problems
Metastatic spread to other organs - eg liver, brain.


Updated October 2013