**Why is my dog drinking his pee when he urinates inside?**

Dog's drinking urine can be a sign of a few different things:

- health problem
- behavior problem  
- improper housebreaking  
- a simple stage that some dog's go through as younger dogs and it passes naturally

This answer is linked with this post https://pets.stackexchange.com/questions/496/how-should-i-correct-my-dog-when-i-catch-him-drinking-his-urine/508#508. 

The inside of your home is the den and pack animals naturally like to keep their dens clean. They will want to relieve themselves as far away as possible from where they eat and sleep.

From [wolfcountry.net][2]
 
>During nursing the mother will clean the pups and stimulates them to urinate and defecate by licking the genital region. She swallows all of their excretions, keeping 
the birthing area clean and odor-free.  

In wolf packs the entire pack protects the mother and the den and help to raise the puppies.

Given he doesn't do this when he is outside, I wouldn't regard it as a problem, per se, he is doing what comes naturally and cleaning up.
  
[Why a Dog Laps Its Own Urine][1]

> One reason is that urine doesn't absorb into linoleum, tile or
> finished wood like it does into dirt, grass and concrete. It remains
> pooled on the floor, tempting the dog's curiosity. Another reason is
> that, while a dog may not be housebroken, it may still know that
> urinating inside is forbidden. It will lap up its urine to hide the
> evidence.

**Conclusion:**


You've stated your dog came from a reputable breeder, implying he was well cared for as a pup; so it's unlikely this is caused from the syndrome of dogs in confined spaces learning to eat and drink their own waste.


Given the information that it only happens when you forget to take him out at night or when  go to bed early (so he has to hold on longer overnight) I would say it's just your dog trying to fix up fix mishap and no great problem.


My suggestion is that the cause of the problem sounds like:
  
 
- He needs to be taken out more frequently.



  [1]: http://www.ehow.com/facts_5329585_dog-laps-its-own-urine.html
  [2]: http://www.wolfcountry.net/