Dogs can count.
At least up to four. I have established a routine with our dog about going out on his own to do his outdoor business.
I am convinced that before we got him, he never had a back yard and was the pet of an older person, living in some small apartment community, who only took him out for a walk once per day.
I have been working for nine months now to break down this inset behavior with him.
I "treat" him for successes and not for misunderstandings. Being that it is often snowy or very wet outside, when he comes in I have him "dance" to help clear his feet (he is a jumper - no problem getting him to dance on a dry surface before he comes back inside). Anyway, there are four tiny, tasty treats involved with our routine.
BUT, if I try to hold back, he will not even go inside without performing all his duties, each of which comes with the benefit of a tiny treat.
He will try all he knows to get his fourth treat, even repeating what he has already done and trying to figure what he needs to to do next.
He can count, at least to four.
On another more comical note: this dog grunts and moans and vocalizes more than any dog I have ever had and that list is in the dozens. He is a talker and he is convinced that his opinion counts for something. I love this little guy!