Why can't cats and dogs be friends?

NO. Cats and dogsare not natural enemys. However, some do not always get along. If you happen to buy a dog and you also have a cat, letting them meet face to face is not the best idea.

When a dog and cat meet, you should put the dog on a leash and let the cat stay inside. Now just let them face each other through a glass door so they can get used to looking at each other.