Demystifying "Tail Chevrons" in Bullmastiffs and Mastiffs

It’s not often that Molosser esoterica or oddity eludes me. But last month, while scrolling through my Facebook feed, I came across a post from National Purebred Dog Day about the “tail chevron” in Bullmastiffs.

Whaa?

“If you look closely at the tail of some fawn Bullmastiffs, you might find a jagged, dark zig-zag—a ghostly thumbprint left behind by the shadows of a 19th-century English forest that served as a tactical weapon of camouflage,” the article begins. “While not codified in the official AKC breed standard, some long-time fanciers point to the ‘chevron’ marking on the tail as a visible echo of the breed’s working heritage.”

An earlier version of the story posted on Facebook described this undulating tail marking as a hangover from the brindling that is also found in the breed. But genetics-savvy posters stopped their feet, pointing to the fact that the brindle pattern is dominant and doesn’t just “appear” after an absence over multiple generations. A few days later, when I retrieved the article, it no longer had any reference to brindle.

No matter — I was sufficiently intrigued. So I visited the BullMastiff Lovers Group, where someone had recently asked: “Question does anyone have a bullmastiff that has zig-zag lines on their tail?”

Enthusiastic respondents posted photos of their own dogs, which on closer inspection appeared to have more of a waving pattern in the hair, which on some dogs was also found on the rump and even along the back.

It reminded me of the marcelled pattern found in some breeds, such as the American Water Spaniel and the Chesapeake Bay Retriever (though the latter’s standard doesn’t use that precise term). Marcelled coats have an S-shaped wave to them, reminiscent of the undulating curves found in the bobbed hair of 1920s flappers.

Marcelled hair.

Similarly wavy coats are sometimes also found in Mastiffs, which, of course, is the Bullmastiff’s predominant ancestor, following the standard’s formula of 60 percent Mastiff and 40 percent Bulldog.

Some of the Bullmastiffs pictured also had different forms of cowlicking, including one who bore a whorl (his owner called it his “whirlpool”) that would have easily been at home on a Rhodesian Ridgeback.

What’s the point in all this?

First, that some people will make legends out of just about anything.

And second, yes, that long-ago ancestors sometimes make an appearance in modern-day dogs. “Fluffs” appear in virtual every Molosser breed. And given the amount of Saint Bernard blood in the Mastiff and by extension the Bullmastiff, a little wave here and there is to be expected.

I wish it was sexier than that, but, alas, the truth usually isn’t.