Why Do Dogs chase Cats?
Is it as simple as dogs are from Mars and cats are from Venus? No. It has more to do with nature and in some cases nurture.
Dogs are predators, cats are prey
People often joke about how dogs hate cats. That’s really not the truth. The truth is a dog is a predator. A dog is hard wired to pursue anything that moves quickly. Cats are also predators, but since they are smaller, they also know they can become someones dinner quite easily. This makes cats very cautious. Cats startle easily. When a dog startles a cat, the cat usually runs for it. It’s in the dogs genes to run after it.
As mentioned above, a dog is hard wired to chase prey. There are many breeds that have a stronger “prey drive” than others. You are far more likely to see a German Shepherd run-in across a lawn chasing a cat than you are to see a Chihuahua or a Chinese Crested doing the same thing. First of all, the cats is probably bigger than the Chihuahua, so if the Chihuahua is smart, he wouldn’t go running off after the cat in the first place. But also the ancestral instincts of the German Shepherd are far closer to the surface than they are for the Chihuahua. German Shepherds have been bred to maintain some of their predatory instincts. This is what makes them such good tracking dogs, guard dogs, attack dogs, and search and rescue dogs.
Some dogs are encouraged to chase cats
Some dog owners think its amusing to watch their dog chase after a cat or other small animals. When the dog makes a move towards a cat, the owner will reward the dog. This praise causes the dog to think running after the cat is a desirable behavior. Many dogs can be made more aggressive when their owners reward aggressive behavior.