Thanks Pierre, for reading and for sharing how Benji's paws smell!

Since the glands in his paws are scent glands, my understanding is that the smell is indeed mostly pheromones and undetectable by us.

From Wikipedia:

"Scent glands are exocrine glands found in most mammals. They produce semi-viscous secretions which contain pheromones and other semiochemical compounds. These odor-messengers indicate information such as status, territorial marking, mood, and sexual power. The odor may be subliminal—not consciously detectable."

Source: https://en.wikipedia.org/wiki/Scent_gland