Actually Pavlov did research about the digestive system for which he got the Nobel prize of medicine a few years earlier.

> Did they interview the dogs and ask them if they actively and consciously decide to produce saliva? > Is "dogs have human-like conscious mind" even a scientific consensus?

That's exactly the point - once you have understood the significance of the experiment you understand that it is not important:

A veteran with PTSD can have a surge in adrenaline, heart rate, and cortisol when hearing a car backfiring but he can not suppress it.

Whether the dog was conscious or not about the salivation is completely and utterly irrelevant. In 1907 this was for the first time evidence of a mind-body connection not being accessible to the consciousness. Seriously, forget about the dog. This is all proven beyond any doubt for conscious humans. Nobody cares about what the dog felt.

Associative learning was already known at that time which in its simple form is just circus tricks. The experiment extended this to physiological responses which are not accessible to consciousness in humans.