Disclaimer: This blog is for educational purposes and the cases described are not from any one animal. Please be warned that this blog contains pictures from real animal post mortems and graphic descriptions of disease.
Chief bounded into the house after returning from his evening run around the park – he knew dinner would be ready for him! Half way across the hall, a couple of metres from his food bowl, he collapsed on the floor. He seemed unconscious, and his owner dropped the can of food she was opening to rush over. Lucky for Chief, his owner was a vet. She tried to keep a cool head as she checked him over. His pulse was fast but weak and his gums were very pale; he was starting to regain consciousness but was too weak to stand up; his breathing was fast and ragged; he didn’t react to his name — these were all signs of shock from blood loss. She carried Chief to the car and sped to the veterinary surgery. His owner already realised that he must be anaemic or bleeding internally. There had been no sign of anything amiss with Chief, and he was checked often at home (no doubt far too often if you asked him!). Even so, at the back of her mind, Chief’s owner knew what could be wrong.
She’d called ahead to colleagues at the practice, and the scene when they arrived was like something out of an ER episode. However, despite their best efforts, Chief passed away. Resuscitation was attempted, but unsuccessful. Distraught, Chief’s owner brought him to us for a post mortem to check whether her suspicions has been correct.
Inside the abdomen, the cause of Chief’s sudden collapse was immediately obvious. Litres of blood filled the space around his abdominal organs. As his owner had thought, he’d bled internally. Our job was to find out from where, and why.
One by one the organs and their attachments were checked, before removing them for more thorough examination. From what we knew already and after finding a blood-filled abdomen (haemoabdomen), top on my list was a haemangiosarcoma. This is what Chief’s vet thought, too.
The word ‘haemangiosarcoma’ can be broken down. ‘Haem’ = blood, ‘angio’ = vessels, and ‘sarcoma’ = a category of tumour, so altogether haemangiosarcoma = a tumour of blood vessels. In fact, these tumours are a mish-mash of rapidly growing and badly developed bundles of blood vessels.
Being cancer, the blood vessels grow uncontrollably and so are poorly formed . They are very prone to bleeding, and will often have many little bleeds all the time. These clot and heal, but will use up many of the platelets and clotting factors in the blood. Eventually there is a big bleed because all these factors essential for clotting have been exhausted. It cannot clot, and just keeps bleeding.
The spleen is the most common site of origin for this tumour. Not surprisingly, when the spleen was examined, we found a large, dark-red mass was present.
Haemangiosarcomas are malignant tumours which can spread around the body by leaking tumour cells into the blood. Some of the places they commonly spread (metastasise) to are the lungs, right atrium chamber of the heart, the brain, kidneys and liver.
These metastatic tumours, which are said to have ‘seeded’ elsewhere, also bleed.
Haemangiosarcomas can originate from other sites apart from the spleen, including the heart, bladder and skin. If they originate or spread to the heart, blood can fill the sac which surrounds the heart (the pericardial sac). Blood in the pericardial sac squeezes the heart from the outside and prevents it from filling properly. This is called cardiac tamponade, and means when the heart beats it has nothing to pump around the body.
The problem with haemangiosarcomas is that they can appear and then grow very suddenly, the animal may have no signs of ill health until the bleeding causes shock and collapse. If they are detected, some can be surgically removed, although they have often spread by this time, so chemotherapy is used in some cases. Sometimes they can be detected because they cause external signs, such as a bladder haemangiosarcoma which bleeds into the pee.
Unfortunately, Chief’s tumour wasn’t obvious until he collapsed, and so there was little his owner could have done in this case.