Why does my dog lick the carpet?

Typically they are lacking some sort of nutrients. Older dogs generally do

this. I've had a couple that started doing this that were around 8 yrs. old. Something to keep close attention to.

My dog does the same. Mine generally concentrates around areas where you might have dropped some food, like around the table, and he does it most in and around the kitchen. It may very well be that your dog is looking for some scraps, although it can very well just be boredom that's making him lick around.

Could be boredom

It could be that it just tastes nice - if anything has been spilt or dripped down the cupboards he will taste it.

My dog (a collie) is exactly the same.

I think the answer is boredom. Try researching environmental enrichments for dogs.

Try this, it's a bit wordy but there are some great ideas like using puzzle feeders;

http://www.hilltopanimalhospital.com/enrichment-do...

It could be food or they smell something on it. If you have any food particles on your hands and touch the cupboard, then that could be it. He could like the cool temp or texture. Could be bored too.

Boredom or there is a nice smell or taste on your carpet.

He could be leaking pee, which can happen in older dogs. He's cleaning it up.