Two possible causes, an internal parasite or a bacterial infection. Given the swollen belly, I would suspect bacterial. Treatment would most likely have been ineffective given the quick death vs first noticing a problem. Maracyn II for SW
(treated in a QT
) for 7-10 days at double the dose added each day would have been the best approach.
If parasitic, Metronidazole would be a good first approch or Piperazine if that was not effective.
No symptoms leading up to this? Seems quite sudden....