“Maybe.”
Not maybe. Definitely. We can’t even experience or directly observe the consciousness of another human being, much less that of an animal.
“however, do we have any evidence whatever that any animal counts to 100 or can conceptualize what 1,000 is?”
Absence of evidence is not evidence of absence.
“I think we can agree that this kind of thought is unique to humans.”
It might be, but that’s just an unproveable assumption, and unproveable assumptions are not the best things to go basing even more elaborate hypotheses on.
Science would be better off, in my opinion, sticking to its more reliable principles, like the idea that it is outside the province of science to try to deal with the unobservable and the unmeasurable. And since consciousness is currently in that category, then it is outside the bounds of science to speak about until something changes.