Sure, there’s that “fighting like cats and dogs” saying, but dogs and cats can also make great friends. And adding a cat to your household may prove simpler than taking care of two dogs — once you get past the initial adjustment period. For one thing, you won’t have to master the art of walking two dogs at the same time.
That said, you need to add a cat carefully. First, think about how your dog reacts around cats he sees outside. If your pup behaves very aggressively, it may not work. However, some dogs who chase cats when they’re out walking behave perfectly gently around a cat who is a member of the family. The best matches tend to be between easygoing, friendly dogs and playful, confident kitties.
Even if you’re pretty sure they’ll do well together, introduce the dog and cat very gradually. Keep them in separate rooms at first, allowing them to “get to know” each other a bit by first sniffing something the other has been lying on. Eventually, let them have supervised visits, but keep the dog firmly under control until you know how he’s going to behave. Don’t leave them together in the house unsupervised until they’ve made it about a month without problems.
There are a couple of other things you need to plan for in a mixed cat-dog house. Some dogs will eat dirty cat litter. It doesn’t hurt them, but it’s disgusting. A hooded litter box is usually sufficient to keep the dog out.
Also, dogs love cat food, so you’ll probably need to feed the cat on a table or other high spot that the dog can’t reach.
Not all dog/cat combinations will work, but with a little diligence and some close observation, you might just create a lifelong friendship that’s beneficial to everyone involved.