Hemangiosarcoma often grows undetected, and presents few or no signs until the cancer is in the late stages of metastasis. However, if symptoms are present, they may include the following (sources: PetMD).

  • Difficulty breathing
  • Pale gums
  • Collapse / loss of consciousness
  • Inability to perform routine exercises
  • Lethargy (weakness, inability to get up)
  • Malaise/depression
  • Loss of appetite (anorexia)
  • Weight loss

Additional symptoms that may become apparent following a medical exam include:

  • Accumulation of fluid within abdominal cavity - visible abdominal distention
  • Accumulation of fluid within thoracic (chest) cavity
  • Trouble with coordination (ataxia)
  • Irregular heart beats/arrhythmia
  • Enlargement of the liver

Note: many of these symptoms (e.g. lethargy, loss of appetite) may be easy for pet owners to overlook or misinterpret. It's important for pet owners to familiarize themselves with these symptoms and to be vigilant of any changes in their pet's behavior or condition.