Coco is in heat. Yes, it happens twice a year, and it requires me to pay a bit more attention to potential, um, situations, than I normally do. It certainly isn't like the old days, when male dogs roamed about, and having a bitch in heat would cause untold commotion, stalking, and desperate howling late at night. These days, it's almost as if nothing is happening. Even though the scent can be detected for miles, people don't let their dogs roam, and there are almost no male dogs who still have their nuts. Of course, almost is not 100%. There's always that chance, so I remain vigilant.

Thanks to the fresh snow on Sunday night, I learned that there is a late-night frequenter to the property who has left tracks demonstrating a keen interest in Coco. Odd, because as I said, there aren't any dogs that wander, or else they'd be waiting for her in the yard. But this is no dog.

Coco's nocturnal admirer is (I am sure) a fox. A red fox (Vulpes vulpes to be exact).

It looks like this one:

I've seen the fox in the yard before, and Coco has a disturbing habit of rummaging around in the bushes where he lives, and I suspect she's eating something I'd rather not think about, and where I'd rather not "go" in this nice clean blog post. But she's familiar with him, and after looking at the tracks carefully, I'm sure they're from the fox. They're longer and skinnier than normal dog footprints, and...

Hell, here's a picture showing the difference:

It's a match with the tracks in the snow. Furthermore, the fox tracks went right through the hedge without any hesitation, and then looped around and through the yard, then through the neighbor's yard, as if this was an extended detour from its normal nighttime prowling route. There were a lot of tracks circling this house, and around Coco's little spots of yellow snow.

Naturally, a "what if" scenario crossed my mind. While it certainly isn't my goal to play mad scientist with my dog, it did occur to me that mating with the fox would not be a physical impossibility, and that if I left her in the yard in the wee hours of the morning, that little guy might just take a shot at it. Foxes are wily creatures, though, and thousands of years of experience in avoiding man would naturally make them hesitant to get caught in a tie-up (from which escape is impossible for twenty minutes or so).

But lets say that for whatever reason, the deed took place. According to virtually every source I have consulted, the odds are overwhelmingly against a successful pregnancy, because there is said to be a chromosomal incompatibility. Foxes and dogs are in the Family Canidae, but foxes are in the subgenus Vulpes, and cannot interbreed with dogs the way wolves and coyotes can.

If pregnancy did occur, the theoretical result would be a "Dox":

Contrary to popular myth, dogs cannot successfully interbreed with red foxes. Dogs have 78 chromosomes, but red foxes have only 38 chromosomes.* This severe mismatch is a barrier to hybridisation. In spite of anecdotal evidence of hybrids and claims that hybrids are superior to ordinary dogs, there have been no genetically verified "doxes".

An unconfirmed female terrier/fox hybrid was reported, and later euthanized (put to sleep), in the UK. British gamekeeper folklore claims that Terrier bitches can produce offspring with dog Foxes. The supposed hybrids (known as a dox) are natural variation in the domestic dog. There has been a reported cross between a domestic dog and a South American fox, but the latter was a fox-like wolf, known as the maned wolf, and not a true fox.

In Saskatchewan, Canada there was another supposed dox, this time a female miniature sheltie with a wild fox. There was a litter of three, but only one survived. The surviving (a female) was sterile, and looked like an almost pure fox, with slight variations. However, the variability of dogs in appearance makes it impossible to determine whether an animal is hybrid based on looks alone.

I'm not about to try, but that doesn't mean I trust Coco.

Right now, she's wearing a very stylish diaper to keep her discharge from staining up the whole house:

I don't know, but if I were a fox, I might think she looked foxy!

But I'm in no mood to make genetic history right now. Besides, Coco couldn't take the publicity.

* Chromosome differences alone are not an absolute bar. Wiki's discussion of "humanzees" states that "having different numbers of chromosomes is not an absolute barrier to hybridization." (There are tions, ligers, and the beefalos.... Oh my!)