Why does my dog bark when I squeak a tennis ball?

Question

My dog Rocky is a healthy 9 month old bull mastiff. For some reason, he has an old toy, which is a squeaky tennis ball. Originally, whenever I would squeeze it, he wouldn’t care much, but lately I’ve noticed that he will bark not very loudly and occasionally will make a sound similar to Chewbacca. Then, when I try to give the ball to him, he isn’t interested. Is there any reason why he is doing this and should I be concerned?

Answer 1

The most probable explanation is that he connects the noise with the ball and with play time and fun. His "Chewbacca sound" is probably an invitation to play, maybe mixed with a slight note of indecision because he would really like to have the ball right now but you're playing with it and he doesn't know how to get it from you.

There are several theories coursing the internet as to why dogs love squeaky toys. Some of them include:

• The toy imitates the screams of a prey animal (source). This seems to mostly affect those breeds of dogs that were specifically bred for hunting, like terriers (source). Dogs are descended from wolves. Wolves may have listened for “squeaking” sounds of injured or frightened prey to know when to attack (source).
• Dogs learn to love the sound of squeaks (source), because they either mean play time or get our attention (because we find those squeaks annoying). In my personal opinion this is the most viable theory. The squeaks add another dimension to the play (sound in addition to the smell and feel of the toy) and may feel more rewarding than biting a toy that doesn't make a sound. Add to that the fact that squeaks don't usually occur outside of play time.
• Squeaky toys activate the feedback loop (source). It's scientifically proven that certain squeaks activate the reward center of the brain, which releases feel-happy-chemicals. Whether this is caused by the hunting instinct or a learned behavior doesn't matter - the dog wants more

So in general there is nothing to be worried about. However, since the toy activates the brains reward center (just like gambling and drugs do), there's a real risk of addiction here. If your dog is a "ball junky" who wants to play every second of every day or if he's so focused on the ball that he ignores everything else around him, you shouldn't encourage this behavior even more by squeaking the toy.