ahhh-chew!!!

The answer is both.
It just so happens that I study this.
Bacterial infections are more easily transmitted.
Viral infections are difficult to transmit, but it is still a risk.
See, viruses are very specific to cell protein coats.
So are bacteria to a certain degree, but they aren't as picky.
Viruses are in most cases species specific. SARS is an example where a virus crossed the species barrier.
Most viruses are difficult to spread between species. Although interspecies viruses are rare, it is something to be cautious of.
Therefore, when I am sick, I am super careful around my furkids.
Just because it is rare, doesn't mean transmission can't happen.
Many times you wont know if you are carrying a bacteria instead of a virus. Bacteria can be passed more easily.
Best to be careful. Hope this helps, but the answer is yes and no.