The thing is it is highly doubtful that Pavlov ever used a bell. Also the experiments were no fun for the dogs.
He redirected the animals’ digestive fluids outside the body, where they could be measured.
https://en.wikipedia.org/wiki/Classical_conditioning#procedures




Since Pavlow is so famous you see often the dogs depicted as cute and someone ringing a bell. Not as fixated pepsin machines. At least in the past that was my mental image. Might be a me problem.