Image is copyright free from Wikimedia Commons
Click "read more" to see my opinion! Even though my answer is below, feel free to post your guesses.
This is an Alapaha Blue-Blood Bulldog and appears to be a brindle-merle piebald with a mask. So, what's his genotype?
He has to be homozygous AyAy sable, because he clearly has a red base color that expresses other pigment. It does not appear that this breed has any other form of the agouti gene, so it's safe to assume he's not carrying recessives.
This dog also has a melanistic mask, and thus he is homozygous EmEm masked. All red and brindle Alapahas appear to have masks, and thus it is safe to assume he doesn't carry any other gene.
This dog appears to have brindle striping and thus is heterozygous kbrk brindle (brindle carrying non brindle). I'm assuming him to be heterozygous because his stripes do not appear to be very dense. It appears that kbrkbr dogs are the dark or "black" brindles sometimes seen.
This dog is also clearly merle. Though it is possible that his degree of white is caused by homozygous merle, Alapahas dog have the piebald gene. Due to the amount of white on his head, I believe him to be heterozygous Mm merle.
This dog is also piebald, and could be either spsp or spsw. Extreme white piebald does occur in the breed, but this dog's degree of white spotting is in the middle, so I believe him to be homozygous spsp piebald.
So, that's AyAy EmEm kbrk Mm spsp, or masked brindle-merle piebald.
I might return to this breed for an Unusual Breed post.
EDIT: Okay, I was mistaken. The Alapaha does in fact have the tan marking gene in its population. Thus, this dog could be either AyAy or Ayat at the agouti locus.