Dogs have an innate instinct to chase small animals that run away from them. When they encounter possums, the possum’s tendency to play dead triggers the dog’s prey drive. Additionally, possums release a foul scent that dogs find unpleasant and confusing.
If you’re short on time, here’s a quick answer: Dogs hate possums because the possum’s tendency to play dead triggers the dog’s prey drive. Also, possums give off an unpleasant and confusing scent that dogs dislike.
In this comprehensive article, we will explore the reasons behind dogs’ animosity toward possums in depth. We’ll cover the evolutionary history behind dogs’ prey drives, explain why possums play dead, analyze the chemical compounds in possum scent glands, and provide tips for keeping dogs and possums safely separated.
Dogs Have an Innate Drive to Chase Fleeing Prey
Origins of Dogs’ Prey Drive
Dogs descend from wolves, who survived by hunting and eating meat. As dogs evolved from wolves, they retained this prey drive and instinct to chase small fleeing creatures. The prey drive is deeply ingrained in dogs’ genetic makeup and persists despite thousands of years of selective breeding as pets.
The prey drive starts in the dog’s most primitive structures of their brain called the limbic system. When dogs see potential “prey” move quickly, the visual information triggers their chase response. Its an innate, hard-wired behavior that originates from wolves hunting to survive.
Just as dogs chase rabbits, squirrels and cats, possums also trigger this strong natural instinct to pursue.
Why Dogs Chase Animals That Run
The fast, jerky movements of fleeing creatures like rabbits, cats or possums tap into dogs’ chase instincts. These stimuli are extremely provocative and stimulating for dogs. When they see an animal like a possum suddenly sprint away, dogs get a strong urge to run it down.
Chasing prey is self-rewarding behavior for dogs and releases euphoric brain chemicals like adrenaline and dopamine. They quite literally get high off the exhilaration of a good chase! This primal adrenaline rush fuels their unrelenting drive to hunt down fast-moving possums and other critters.
Possums Trigger the Prey Drive by Playing Dead
Playing dead is a possum’s natural first line of defense against predators like dogs. But this actually triggers dogs’ prey drive instead of deterring them. The initial movement of the possum running for safety provokes the dog. Then once cornered, the possum lies utterly still, pretending to be dead.
To curious dogs, the motionless possum now represents a toy for them to pounce on or pick up in their mouth for entertainment. Unable to restrain themselves, dogs will harass, attack and even kill lifeless “playing dead” possums.
Sadly, a possum’s best survival mechanism ends up arousing a dog’s excited chase and prey drive.
The Purpose of the Possum’s Defensive ‘Playing Dead’
Instinctive Thanatosis Protects Against Predators
Possums have evolved an ingenious defensive strategy to protect themselves from predators like dogs – instinctive thanatosis, or playing dead. When threatened, possums enter a comatose-like state where their body goes limp, heartbeat and breathing slow dramatically, and they appear lifeless (1).
This response is involuntary and triggered by extreme fear and stress.
Playing dead can deter attackers as the seemingly lifeless prey loses its appeal – predators like dogs typically prefer live, active targets (2). Additionally, the possum’s emission of a foul-smelling fluid from its anal glands simulates the smell of decay and putrefaction, further repelling the predator.
This unconscious act of playing dead is so convincing that it fools many predators into believing the possum is rotten carrion not suitable for consumption.
To Dogs, Lifeless Prey Is Confusing Yet Intriguing
Most dogs retain their innate drive to hunt and will eagerly chase possums that run and hide. However, when cornered possums play dead, this thwarts the dog’s expectation for an active chase and kill. The abrupt change from fleeing prey to lifeless corpse is perplexing and frustrating for dogs.
They often continue investigating through aggressive pawing and biting, motivated more by curiosity than hunger at this point (3).
Additionally, the pungent scent emitted by frightened possums can be quite intriguing and irresistible to inquisitive dogs. So while playing dead may initially confuse dogs, the odor produced around the anal region actually draws dogs in to investigate further through licking, sniffing, and biting the area – much to the possum’s dismay if pretending to be dead!
The fact remains dogs have an innate drive to hunt possums. When this desire is paired with humans startling possums by day when they typically sleep, unfortunate interactions occur. Possums just want to wander at night, find food, and be left alone!
Their only defense is playing dead and hoping their Oscar-worthy performance convinces dogs they are not prey worth pursuing.
Possums Release Repulsive Scents When Afraid
Chemical Composition of Possum Scent Glands
Possums have two main scent glands located near their anus and genitals that produce a foul-smelling secretion when they feel threatened. The main components of this secretion are volatile sulfur compounds like hydrogen sulfide, methyl mercaptan, ethyl mercaptan, and thioacetates that give feces and rotting flesh their characteristic odors.
In addition, compounds like isovaleric acid and cresol contribute to the potent, pungent smell. When encountering predators like dogs, possums reflexively emit this noxious cocktail that lingers heavily in the air to deter pursuit.
Dogs Find Possum Odors Unpleasant and Alarming
A dog’s sense of smell is 10,000 to 100,000 times more acute than humans. Their nostrils have over 220 million olfactory receptors attuned to a vast range of scents compared to our humble 5 million. So dogs experience possum scents on an entirely different scale of sensitivity.
Volatile sulfur compounds trigger specialized olfactory receptors in dogs that convey signals of danger, disease, and decay – key threats for avoidance. Additionally, thioacetates smell nauseatingly sulfurous and cresols reek of urine or feces.
When combined in the possum’s defensive spray, these chemicals assault a dog’s nostrils with an intensely sickening stench that likely induces profound disgust, fear or anxiety.
Veterinarians also note that just a tiny amount of isovaleric acid can cause gagging in dogs. So faced with gallons of thiscompound from possum scent glands, most dogs beat a hasty retreat rather than endure the hideous odor.
Their powerful noses tell them quite clearly that messing with possums is an awful idea!
Keeping Dogs and Possums Safely Separate
Block Possum Access and Dog Escape Routes
Possums like to sneak through small openings to access food sources, so it’s important to possum-proof your home and yard. You’ll want to block any holes where possums could enter, like openings in roof vents, cracks in the foundation, spaces under porches, etc.
Use wire mesh, caulk, or other sealing materials to plug these access points.
It’s also key to make sure your fence is secure with no weak spots where your dog could escape and go possum hunting. Possums tend to lurk in bushes, woodpiles, sheds and other semi-sheltered spots, so trim any overgrown vegetation back from the fence line.
Also check that fence gates latch securely and add locks if needed. Keeping your dog safely contained in the yard will prevent those hair-raising encounters.
Train Your Dog to Ignore and Avoid Possums
While blocking physical access is important, you also need to train your dog to leave possums alone. Use positive reinforcement like rewards and praise when your dog disengages from possums. If he spots one and then looks back at you, celebrate that choice! You can also teach a strong “leave it” cue.
Asking your dog to “leave it” then rewarding calm behavior teaches him that possums aren’t to be chased.
Finally, keep your dog leashed on walks to maintain control. If you spot a possum, create distance and use treats to re-focus your dog’s attention on you instead. Staying vigilant and being prepared to intervene will prevent those terrifying tussles.
With some prevention and training, you can keep both pets and possums safe!
Conclusion
In the evolutionary battle between predator and prey species, there are bound to be antagonistic behaviors. Possums have developed defense mechanisms like playing dead and scenting that successfully protect them from most predators – but they also serve to engage a dog’s instincts in all the wrong ways.
Now that you understand the natural reasons dogs dislike possums, you can take preventative measures in your own yard. Securing your property, training your dog, and encouraging both animals to avoid confrontation will allow possums and dogs to coexist safely in your neighborhood.
