What happens when Watson makes deductions about the walking stick?

Deductions are more Holmes's thing really, so when Watson tries his hand at the art of deduction, it's not surprising that he often gets the wrong end of the stick. (No pun intended.) However, one shouldn't be too critical, because on this occasion, Watson does at least correctly deduce that Dr. Mortimer must practice medicine in the country, as his walking stick shows signs of having been used quite a lot.
As we might expect, though, it takes the legendary Sherlock Holmes to flesh out the details and provide us with a much more complete picture. He deduces that the initials on the walking stick, C.C.H., indicate that Dr. Mortimer was a student at Charing Cross Hospital in London. From this seemingly unimportant nugget of information he deduces the fact that Mortimer is a young man who's not especially ambitious in his career, as he's chosen to practice medicine in the countryside rather than the city. Most impressively of all, Holmes is able to establish from the tooth marks on the walking stick that Dr. Mortimer is the owner of a medium-sized dog.
There's a reason why Holmes is the detective and Watson is his assistant. This episode shows us what that reason is: Holmes's vastly superior powers of deduction.