How many species of dogs are there ?

I think most people would be quite surprised by the answer, which I found at the QI column at The Telegraph.

And are there more species of dogs than horses?  A yes-or-no answer is sufficient here.

Before you click the link, do your best to come up with answers on your own.  I will also post the answer in the Comments in case the source undergoes linkrot.

You learn something every day.