Why do dogs like tennis balls? Raise your hand if you have a dog who loves to chase tennis balls and would do anything for a game a fetch. Even dogs who do not like to play fetch will find tennis balls intriguing enough to chase around and play with, but unlike dogs who love to fetch, they'll rather keep the tennis ball for themselves. So why do dogs like tennis balls so much? Turns out, dogs see balls differently from the way we see them, and the instinct to chase them dates back to ancient times, long before being fed in shiny bowls and given fluffy dog beds.
A Glimpse into the Past
Even though dogs have been domesticated for centuries, old instincts are still alive. In order to survive, a dog's ancestors had to hunt, and in order to succeed, they relied on predatory sequences of behaviors which consisted of eyeing, orienting, stalking, chasing, grabbing, killing , dissecting and consuming. These behaviors, classified as predatory behaviors, were not learned behaviors; rather, they came naturally as they were essential for survival purposes. It is thanks to these instincts, and later, the process of domestication that we get to enjoy our dogs today.
A Watered Down Instinct
In domesticated dogs, predatory drive is less pronounced than in their wild cousins who depend on their ability to hunt to fend for themselves, explains veterinary behaviorist Dr. Nicholas Dodman. We will therefore find many breeds of dogs who still display some predatory drive, but the instinct has been customized through many years of selective breeding. Humans have basically bred a dog's instinct to bite and kill, out of the domestic dog, explains dog trainer Victoria Stillwell. This modification has allowed humans to utilize several working dog breeds in several tasks.
We therefore have herding dogs who still display predatory behaviors such as eyeing, stalking, chasing and nipping, but to prevent harm to the animals being herded, the final consummatory phase has been bred out. Dogs bred for retrieving downed fowl will retrieve downed fowl, but they do so with a soft mouth that leaves no teeth marks. Pointers sniff and detect wild game, but they limit to their predatory behavior to pointing. Spaniels instead limit themselves to locate and flush birds out of bushes so that the hunters can point and shoot.
What Dogs See
Despite the fact that predatory behavior has been "watered down," or perhaps, it's better to say it has been "truncated" through years of selective breeding, a dog's instinct to chase still remains strong. In modern settings, with no animals to chase, dogs often resort to finding different outlets for their predatory drive. This may include chasing bikes, shaking stuffed toys, digging holes, playing with Frisbees, playing with tug toys, and of course, chasing tennis balls. To us humans, tennis balls are meant to be bounced around using a tennis racquet, while to dogs they act as substitutes of prey, fulfilling an instinctive need to chase, pounce and grab, and in some dogs, even dissect, but all in the name of play.
Just Like Prey
When you toss a tennis ball, its erratic, unpredictable movements mimic those of panicked prey. The dog will therefore chase the tennis ball, catch it and then he may shake it with a fast side-to-side movement meant to"kill it." This side-to-side movement is a nifty neck-breaking behavior meant to kill a small prey animal, explains Jean Donaldson in the book "Oh Behave! Dogs from Pavlov to Premack to Pinker." Some dogs even go further on to remove the fuzzy layer of "skin" break the ball into pieces, "disemboweling" it of its contents, and dissecting it with a satisfied face. While all this may sound gory, consider that usually dogs don’t confuse toys such as a tennis ball with live animals or people, explains dog trainer Victoria Stillwell. They know the difference.
Predatory drive is a far cry from aggression. Indeed, the instinct to chase prey objects is greatly different from other forms of aggression, such as aggression triggered by competition for resources or self-protection, explains dog trainer Pat Miller. However, just because predatory behavior is instinctive doesn’t mean we should accept its inappropriate manifestations. It's our job as owners to ensure our dog's predatory instinct doesn't get them in trouble and to provide our dogs with appropriate outlets for their predatory behavior rather than suppressing it. One great outlet includes chasing and fetching balls.
Watch the Dangers
Tennis balls and dogs may seem like a perfect match, the ball bounces erratically, and the fuzzy covering allows dogs a good grip, but there may be some dangers to be aware about. Dogs with strong jaws may compress the ball and the ball may pop open in the back of the dog's throat causing suffocation, warns veterinarian Dr. Marty Becker. Dogs who chew tennis balls also risk a blockage. The cheaper versions can be easily chewed in half even by dogs with weaker jaws and some are even full of chemicals. If you choose to use tennis balls, always supervise play and don't turn tennis balls into chew toys. Even better, invest in safer, sturdier toys.
Did you know? Another danger coming from chewing tennis balls is dental wear. According to the American Veterinary Dental Society, dogs that chew on tennis balls cause wear to their premolars and canines overtime.