What is hemangiosarcoma (HSA)?
HSA is a very aggressive cancer of vascular tissue (blood vessels.) Because of this it can form almost anywhere but tumors most frequently initiate in the spleen, heart, and occasionally the skin. Because it begins in a blood vessel it usually spreads, often to the lungs or liver.
How do I know if my dog has HSA?
If you find a dark or purplish lump on your dog’s skin, it may be an HSA tumor. You might also find a soft mass under the skin or a hard mass with an associated ulcer on the skin surface. However, most cases are internal. Dog’s whose cancer starts in the spleen or heart may be lethargic, anorexic, lose weight, develop fluid in the abdomen, or have difficulty breathing. If your dog has tumors you can see or feel, or any of the internal symptoms for more than a day or two, get your dog to the vet for an exam. Sometimes a weakened blood vessel will rupture causing an internal bleed which can be catastrophic. If the dog is over 4 years and suffers sudden collapse this may be a sign of HSA. A veterinarian will examine the dog, do blood tests, or tumor biopsy. If the abdomen is distended he may withdraw some of the fluid for exam. Short of direct identification of a tumor and biopsy, diagnosis is made by exam and ruling out other possible causes of the symptoms.
What does having HSA mean for my dog?
Unfortunately, prognosis for this cancer is very poor. Most dogs only survive weeks to a few months after diagnosis. Sometimes the first indication you have that your dog is sick is a sudden catastrophic collapse. Any Aussie over 4 years that dies suddenly from no apparent cause may have died from HSA; if at all possible a necropsy should be done to verify whether or not HSA was the cause. The skin form, if caught early enough, may be cured by tumor removal. It is also the easiest type to treat with the longest survival time.
Is HSA common in Aussies?
The 2007 ASHGI cancer survey found it to be by far the most common cancer in the breed. The 2009-10 health survey found that 5% of the dogs surveyed had hemangiosarcoma and the longevity survey conducted in 2017 indicated that frequency since then has increased to 18% of total deaths.
Is HSA inherited in Aussies?
Yes. Specific gene(s) have not yet been identified but they probably are risk factors – not a guarantee the dog will develop cancer but something that significantly increases the likelihood the dog will do so. The 2017 longevity survey found that dogs with hemangiosarcoma were very likely to have offspring that developed the disease.
What does HSA mean for my breeding program?
Affected dogs are often old enough they may have been bred already. If semen is stored from an affected male it should be discarded. First step kin of affected dogs (parents, full and half siblings, and offspring) should be bred only to mates with pedigrees as clear of HSA as possible and who have no affected close relatives.