It's time to get you clued up, just in case.
The space occupied by someone with a virus gets contaminated by the virus. Any virus. Including Ebola. Most viruses break down outside of a live body, but Ebola survives in a dead body, so it probably survives on surfaces too. Sweat, skin cells, you name it. I'm a tad worried about water supply, even: urine's infectuous too.
Given that, then it's not what's in the dog, but what's on the dog, which was a primary cause of concern. Don't minimise this one until we know what kills it: many bugs don't like the cold, SARS didn't.