Human waste is classified as a BioHazard it contains the following very unpleasant bacteria.
- C. diff
- cholera
- E coli
- Dysentery
- Norovirus
- Hepatitis A and E
- Giardia
- Pinworms
I suppose that is why we go to such extremes to make sure that it is disposed of in a safe manner not just chucked in a bin for someone else to find. The outside of any bag can also have traces of the above.
The health of the Nation was drastically improved by digging up the roads and putting in sewers to take away the feces and urine from the gutters and also away from water courses.
Cholera is an infectious disease that causes severe watery diarrhea, which can lead to dehydration and even death if untreated. It is caused by eating food or drinking water contaminated with a bacterium that can come from human feces.
Dog muck on the other hand does not create much of a problem for humans. We don't get cross infection from it but it can be a hazard to health especially from slipping in it and falling. If dog muck was classified as a BioHazard humans would be up in arms about it.