what killed my dog?

[jdog2011]

my jack russell was 11 1/2 years old.  she was certainly declining in vitality, and there were a few episodes in the last couple of months when she would inexplicably refuse to eat for 3 or so days and act very lethargic.  occassionally i would find a small amount of bloody -looking discharge from her rectum, but my vet said all her bloodwork looked normal.  

the day before she died she seemed tired but otherwise normal.  she fell asleep in my bed like always, but then around midnight in my sleep i accidentally pushed her and she fell off the bed.  this has happened dozens of times before, but this time right after it happened, something definitely seemed wrong.  She started alternating between labored  breathing and light rapid panting.  she seemed to have trouble getting comfortable.  every few minutes her stomach muscles contracted.  i looked over her body and couldn't find any signs of injury, nor did my touch on any part of her body seem to bother her.  she was even able to walk outside for a bowel movement.  there was no blood in her stool.  after monitoring her about an hour she seemed to be better and we both laid down and went back to sleep.  when i woke again at 5 am to check on her, she had died.  her body didn't look bruised or unusual in any way.  i later found 2 tiny drops of blood on the blanket she had been laying on.

is it possible that my dog died of internal bleeding from just a 2-foot fall off the bed, or was there an underlying health issue i didn't know about?  i'm devastated over this and would really like to know what happened.  i live in a very small town and there was nowhere i could have taken her in the middle of the night, but i still feel awful about what happened.

[jdog2011]

Thank you so much for taking the time to answer my questions.  Your answer gave me so much piece of mind knowing it was not my fault and there was nothing I could have done to save her.  I appreciate it very very much.

[Aleda M Cheng, D.V.M., C.V.A]

I am very sorry about your dog!

I think that your dog's loss of vitality and occasional episodes of inappetance may have signaled an internal problem in her abdomen such as a tumor of the spleen or liver, or both, such as a hemangiosarcoma or other vascular tumor.  These abdominal space occupying masses can cause inappetance and inexplicable lethargy, which can occur as a result of small ruptures within the tumors.  These tiny ruptures cause blood loss within the abdomen and therefore a transient anemia which can help to explain the lethargy.  The occasional blood that came out of her rectum can also be explained by one of these small ruptures.  

On the night of her death a large rupture could have occurred coincidentally to her falling off the bed or precipitated by the fall.  This was no fault of your own since the mass and potential for rupture was a time-bomb just waiting to happen.  The rupture caused the sudden panting and labored breathing.  The rupture also caused massive internal bleeding which resulted in death.  Please don't feel responsible.  The tumor was responsible and not you.  Lastly, there was nothing that you could have done to save her.

Of course this is only my best guess since only a post-mortem exam can give a definitive diagnosis, but the symptoms really seem to fit.