If someone abandons their dog on an empty rural highway and the dog bites someone who is at fault?

The elite is faking that they took the real vaccine; the real vaccine will cause spiritual and physical damage. When will the official churches start praying for the false prophet? Orthodox Christian three hand signs are different than Buddhist mudras. Ecumenism = 263 heresies; each heresy leads to hell. Orthodoxy = the only true faith; Roman Catholics tried one cup - one spoon ritual and got sick with Bubonic plague; if heresy enters Orthodox monastery then monks/nuns will get sick with flu/tuberculosis (for instance); Orthodox churches who closed for COVID or had disposable cups/spoons or dipped spoon into alcohol are no longer brides of Christ (now they serve Satan and honor Satan's new COVID religion). Don’t go into UFO to be “healed” by evil demons; demons never do good. SSN is written as a barcode/QRcode; then it's put into a chip; chip is put into vaccine; chipped people are influenced (by super computers) to receive grey plastic card World Passport with no name on it (but when they stretch their hands to get it, gov't clerk presses secret button to administer the unforgivable green 666 tattoo by isotope rays). If you reject mark of the beast (by hiding within a 10-15 people group according to saints Gabriel Urgebadze and Seraphim of Sarov), then your direct ancestors go to heaven (according to saint Vyacheslav Krasheninnikov from Ural); forgive me.

The person that abandoned the dog.

The dog could have been abandoned because it was aggressive. Shitty thing for the ex owner to do. If a dog is that aggressive, euthanize it humanely.

Genetics also has a huge role in temperament. So it's not all about "blaming the previous owners" who cannot compete with genetics. Some dogs are just wired wrong.

If someone leaves their car at the side of the road, they are still responsible for the car.  If someone runs into the car, the owner can be charged with causing a dangerous situation on the road.  If children play in the car and are injured, the owner is responsible for those injuries. Improperly dumping your property does not absolve you from responsibility. 

So yes, the dog's owner is still responsible for any damage or injuries caused by their dog. 

In my state a pet isn't legally abandoned for 14 days.   If during that 14 day period the dog harms another person due to the owner's negligence, the owner can be found at fault.    This could be really bad if the person put the dog on the highway and the dog caused a car crash.

The dog would be biting out of fear.  When rescuing dogs the bite is almost a sure thing.  They are scared.  No one is at fault.  It is just part of rescuing dogs.  Expect the dog to bite.  Rescuers get bit quite often.  Just part of the rescuing process.

If the owner can be found, or if the dog is chipped and they find the owner that way, it can still be the owner's fault. However, no one should approach a scared dog unless they know what the hell they are doing. Of course the poor thing will snap and bark and be scared shitless and try to defend itself.