Except that there are no examples of Ebola being transmitted to a human by a dog. Humans are regarded as not infectious when asymptomatic. Dogs apparently are, too. Otherwise, there would be some evidence of transmission from dogs to humans. There is for other primates. There is for bats. Not dogs, though.
People are freaking out over one paper written in 2005 that showed dogs in Ebola hot zones tested positive for antibodies to Ebola. That’s all it showed, everything else is speculation.
You very likely have MRSA in your nose, you do realize that, don’t you? Why don’t you come down with it?
a) animals (including humans) that have antibodies but have probably cleared enough of the virus to be no longer infectious, i.e., they may have small amounts of the virus but not enough to transmit;
b) animals (including humans) that are fighting off the virus successfully (and so have no or few symptoms) but who carry an infectious level of the virus;
c) animals (including humans) that are not fighting off the virus successfully (initial stages) but who show no or few symptoms yet but who carry an infectious level of the virus;
The fact that there is no direct proof of transmission from dogs is meaningless (there's no direct proof of transmission from bush meat either: by the time an outbreak is detected, the meat and carcass are long gone).
The question is: can an asymptomatic dog carry enough live virus to serve as a transmission vector? We probably don't have enough knowledge to make that judgment, but based on the disease and other animal cases it certainly seems possible.
Don't get me wrong: I feel sorry for the dog, but I don't see any reasonable alternative to putting it down and cremating the remains.