Oh man, I had a sweet little lab whose personality changed like that. She never ran to attack out of the blue, but took great offense if a strange dog “got up in her grill” as dogs do to get acquainted.
Her necropsy turned up a liver dark and hard as a stone, according to the vet who did it. (Her liver levels got checked every year beause she was on anti-seizure meds, but the last test was not particularly alarming.)
A liver can “blow” without warning and quite suddenly.
My sweet old Ibizan was being treated for degenerative myelopathy and on Nov 4/08 day [yeah, it was a VERY bad day] I awoke to find her totally bloated and drowning in her own body fluids [massive, acute ascites] because her liver gave out in *one* night.
She was fine when I went to bed and dead 7 hours later.
Just like that.
I’m sure the poll people thought I was insane because my eyes were swollen from crying but I went to vote anyway, for all the good it did.
I’m terribly sorry for your loss.
Sometimes, no matter what you do, you can’t do anything.
:(