Cant determine cause

F 1yr 8mo 9lbs Miniature Shnauzer Shows (32hrs) low heart rate, lethargy, dazed, diarrhea, unsteady on legs, normal blood pressue Ruled out: heart, kidney, liver Vets considering toxin (of unknown origin), gastric disease Any insight would be helpful as we want our sweet girl home and its been hard with the vets not being able to identify whats going on. She has been hospitalized and being monitored.

Hello!  It's not unusual for vets not to have a diagnosis at first but often the most important thing in the early stages is not that that they can name the disorder, but give appropriate treatment for the symptoms which may be lifesaving.  However, medium term knowing what the problem is is very helpful!  I wonder if they have measured Potassium and Sodium (Addison's), and checked for Thyroid disease?  However, most vets will have a list of things it 'could be' by now (the differentials) and be working through them - they should be happy to explain this process to you.