Guys i know these fellows are not koolies, but i would like to call on your expertise here.

I have 2 Tibetan Spaniel 16 month old brothers. entire males. These little guys have lived together, played together, share a pen, sleep together on the same chair since day 1, but the last few days they just want to get stuck into each other.

Tibbies are normally a very sociable lot that get along well with anything, This behaviour has me totally puzzled, as to why all of a sudden.

There are no females in season or even close to coming in, and normally when the girls are in, these two boys still managed to stay together without fighting.

After they have a scrap, within a minute you will see them licking each others face as if comforting each other.

With these two the top dog has clearly defined his position as top dog, and as the other one stands back and lets top dog go first to me , or the water dish or the food bowl etc i would say they have outlined their status with each other.

Nothing else has changed in the house to throw them off balance in any way, i am puzzled by this, any ideas what may be going on here?

At 16mths their hormones could still be causing them to do this as I know with my huskies that between 15-24mths is the 'narky' time with my boys. I'd say it could just simply be establishing/maintaining a pecking order as they mature, the submissive one may be giving subtle "challenges" or testing the water a little with the dominant one.
I know with my huskies 2 boys, usually brothers that get along perfectly as they grow will suddenly start with one another out of the blue & often I can't keep them together with girls around in heat as they really want to pick at one another until early 2yr olds or nearly 3yr olds when they have matured hormones have settled down.

Thats my take on it anyways...

Thanks mushoz, that makes sense to me too.

If it comes to it, i would even consider getting one desexed, but dont really want to resort to that unless i have no choice as they are both showing great potential for the show ring.

But some people have even said that desexing doesn't always stop this type of problem anyway.