[QwOpHGyZ]

My puppy is 19 weeks today, for the past few weeks i have noticed some brown/light brown "highlights" showing up on both sides of his neck, (he is black with some white on his chest & paws.) We were taking a walk yesterday and I noticed some brown/bronze on his sides (very suddle but noticesable) almost like a pattern of "lines". Almost like a brindle? Can anybody tell me what this is about? Has anybody experienced this before? What is going on/ should I be corncerned about this? Good thing is that he is very shiny and the "highlights" makes him look even shinnyer. Any input will be greatly appreciated. Thanks in advance...