Monogamy, Not a Doggy Thing
The appearance of a single pitch-black pup in a litter of immaculate white puppies might have people wondering whether it's possible for puppies to have more than one father. Who's your daddy, little pup? While you won't find puppies taking paternity tests on the Maury or Jerry Springer show to help solve a family mystery, in dogs genetics may often pitch in and provide a plausible explanation. If you're scratching your head in disbelief wondering whether Sophie, your purebred dam messed around with some determined mutt in the neighborhood, or if you're plain curious, read on to discover a little more about the world of canine reproduction and genetics.
The world of animals is populated by several romantic examples of monogamy coming from beavers, otters, foxes, bats and wolves , but dogs, even though related to wolves, are far from being monogamous beings. Why is that?
While dogs and wolves share the exact same number of chromosomes (78 arranged in 39 pairs) they are quite different beings, courtesy of the thousands of years separating them. Indeed, there are more than a dozen of differences between wolves and dogs which sets them apart. Many of these differences are due to domestication. Just as with dogs now shedding for the most part year-round rather than seasonally as they used to, domestication has likely also played a role in making them more promiscuous.
What's the purpose of being monogamous in the wild? Most likely, monogamy offers some advantage in altricial species who give birth to young that are particularly vulnerable and benefit from extra parental supervision and protection.
This remains the most commonly accepted explanation since offspring appear to have a better chance of surviving when both parents are involved in raising them, according to Live Science.
Wolf Versus Domestic DogThe Making of A Multi-Sired Litter
Did you know? When it comes to being faithful, urban coyotes win the title as most loyal partner. According to a study conducted by scientists with Colorado State University, "coyotes living in cities don’t ever stray from their mates, and stay with each other till death do them part."
According to Steven Lindsey, wolves tend to reach sexual maturity at around 22 months. Wolves are monogamous and females go into heat only once a year during peak breeding season giving birth to pups when the rigors of the winter are over.
When the wolf pups are born, they are in a helpless, underdeveloped state and are raised in their maternal dens so they are safe from predators.
Helping raise the pups is a family affair that involves the older siblings, aunts, and uncles and also the pups' father. Since the pups are too young and vulnerable to venture out of their dens, it's the job of dad and extended family to bring back to the pups tasty meals of regurgitated meat, according to The Field Museum.
When it comes to dogs though, things are quite different. Dogs are polygamous and female dogs can go into heat between 6 and 12 months of age and for the most part bi-annually (the basenji is an exception) pretty much at any time of the year. Female dogs are often willing to mate with multiple partners, given the opportunity. And when the puppies are born, they are raised in comfy, temperature-controlled whelping boxes.
Dog owners have replaced the extended family that a dog's ancestors relied on and are readily available for assistance. For many years, indeed dog owners have assisted with the whelping process, taking care of struggling pups and, instead of regurgitating food, weaning pups are provided with a nice bowl of puppy mush! How's that for convenience?
"Wolves breed only once a year, during the winter months so the pups will be born in the spring, when food is plentiful and the weather less severe. The season begins in late December and proceeds until late February or early March."~Wolf Education and Research Center
So we know for a fact that dogs are polygamous. Indeed, for centuries, humans have been selectively breeding male dogs with multiple females and females with multiple males. With females, though things can get tricky, so for those folks professionally breeding, it's best to let them breed with only one particular male during a heat cycle and then keep'em under strict supervision as accidents have been known to happen even under the nose of the most observant and responsible breeders.
If allowed to breed with multiple males, a female dog may therefore give life to what's known as a multi-sired litter or dual-sired litter. Here's a little sneak peak into what happens.
When a female is in heat, she produces several ova (eggs) that are readily available to be fertilized for several days. Since one ovum (egg) and one sperm is all it takes to make an embryo and ova are released over a 24 hour time span, Sophie can have some eggs fertilized by Romeo and then some others fertilized by Homer, giving life to a litter of pups fathered by different dogs. So yes, puppies can have more than one father, meaning that within the same litter, some puppies may be sired by one male while the rest may be sired by another, but never both.
It can therefore be quite upsetting for a breeder, who paid a nice amount of money for stud services (so that Princess the purebred poodle could be mated with handsome Happy Jack, a multi-champion poodle) to discover that Scruffy the neighbor's mutt was able to breed with Princess a day later when she escaped the yard. The breeder may therefore not be too enthusiastic when he discovers 63 days later that Princess gave birth to a part purebred, part mixed-bred litter!
The Truth Comes Out
If you really need to know whether you're dealing with a multi-sired litter, you can skip all the drama associated with a lie detector test and instead invest in a good dog DNA testing kit for dogs which should be able to tell you whether your female dog had an "affair" with more than one dog. Some DNA tests should be also helpful in matching up the DNA of a particular puppy with the DNA of a suspected biological father. With this proof in hand, you can therefore register a multi-sired litter and provide the proof to any buyers.
Did you know? Some breeders purposely breed their female dog to two different studs either because of poor-quality or low sperm count or to attain more genetic diversity without having to breed too many times. These multi-sired litters can even be registered with the American Kennel Club under "Multi-sired litter registration" as long as both parent dogs are purebred breeds and all criteria are met including proof of parentage determined through the AKC's DNA Profile Program.
- The Field Museum, Dedicated Animal Dads That Care for Their Young, retrieved from the web on October 22nd, 2016
- International Wolf Center, Wolf Families. retrieved from the web on October 22nd, 2016
- American Kennel Club, Stud Double, retrieved from the web on October 22nd, 2016