The Birds and the Bees, part one

The Birds and the Bees, part one

Most of our dogs and cats are spayed at a pretty early age nowadays, in hopes of stemming the tide of homeless pets. Timely spay surgery also has a protective effect against some cancers, so the majority of our female pets will never know the nuisance of a reproductive cycle. We ourselves have become a generation of pet owners that knows little about the mating habits of the domestic dog and cat, and yet there are still many reproduction-capable pets out there. Here is a peek into their private lives.

Let’s begin with the canine: female dogs can begin producing offspring when they pass through their first estrous (or “heat”) cycle. That’s usually around six or seven months of age, with smaller-breed dogs maturing first and large-breed dogs maturing later, sometimes past the 12-month mark. The canine estrous cycle runs its course approximately twice a year and is marked by swelling of the genital area, as well as a light flow of red- or pink-tinged liquid. The discharge usually persists for about ten days. Just as that’s winding down, fertility levels peak and, for the next ten days, she becomes receptive to the advances of male dogs. These gentlemen will be attracted from surprisingly remote locations by pheromones carried on the air (which are undetectable to the human nose). Male dogs will go to great lengths to reach a female at this time. It’s a shock to many people that closely related dogs will mate with each other, so don’t make any assumptions at all regarding your pet’s inhibitions. In general, dogs don’t have them.

When the swelling goes down and the neighborhood dogs start staying home to watch TV, the excitement is over for a while. But inside the female dog, changes continue to take place. Regardless of whether puppies have been successfully conceived, her hormones go through all the fluctuations of a complete pregnancy. That means lab tests don’t distinguish between pregnant and non-pregnant dogs, so no one can tell for sure what’s going on in there until the appearance of actual fetuses on an ultrasound. High blood levels of hormones make an empty uterus especially prone to infection. That type of infection is very dangerous and usually requires emergency surgery.

False pregnancy occurs when the female dog’s body starts to really believe that its empty uterus is carrying a litter of pups. You might even observe a distended abdomen and milk production in the mammary glands. This condition often comes complete with phony “pups”. Good mothers will attempt to nurse the “pups” and bathe them meticulously, oblivious to the fact that their brood is actually composed of stolen slippers and Beanie Babies. Once any pregnancies and false pregnancies are completed, it’s time for a female dog’s body to return to its normal state. Pups are nursed and weaned, slippers make their way back under the bed, and Beanies return to the toy box… until the whole thing starts all over again.

Next time: the secret life of cats.

Dr. M. S. Regan