Your cat will need 24/7 access to a dog-free room where they feel safe and have everything they need. Their sanctuary room must be fully enclosed, which means a secure door and no open ceiling. It can be large or small but must contain food and water bowls, a scratching post, bed, litter box and some toys. 

In preparing the room, you need to cat-proof it by removing any breakable items, poisonous plants, toxic cleaning products and all human medications. Hide electric wires and cables, so your cat can’t chew on them and risk electrocution. Cats feel safer when they have little cubbies or tunnels where they can hide. Do what you can to get these set up as well. 

All dogs should learn basic commands, like “sit” and “down.” So, if the new pet in the home is a dog, start teaching him to obey these commands. Training should be a pleasant experience for your dog, so keep sessions short and make sure you reward with treats. You can learn how to train your dog with videos on YouTube or your pet supply store may offer training sessions.  

Before introducing your dog and cat, take your new pet to the vet to get the all-clear on his/her health. Your dog and cat should be kept in separate rooms for the first few days at least, with your cat in his/her sanctuary room. They will get used to one another being in the house just by hearing and smelling each other. 

They will learn to associate the other pet with something enjoyable if you feed them at the same time with each on the other side of a closed door. Every time you feed them you can place their bowls a bit closer to the door. Keep this up until you see that both pets are perfectly calm eating right up against the door. 

Now that they are comfortable eating “together” on opposite sides of the door, it’s time for them to officially meet. Do this in a common area of your home, not in either pet’s sanctuary room. You must be there to observe their interactions. It’s best if the first few times they meet it’s for a short time only and it’s kept calm. You need to contain your dog on his/her leash while your cat is free to wander. Neither pet should be held in your arms, as someone could get hurt if either pet gets upset or aggressive.  

Encourage good behavior by asking your dog to sit and if he complies, give him/her a treat as a reward for being calm. To be fair, your cat should also be given treats. If one or the other starts getting aggressive, it’s up to you to calmly distract them. You can do this by tossing a toy to get the cat to leave the room or redirect your dog by calling his/her name and giving a treat. It’s now time to separate your pets again by taking them both to their sanctuary rooms. 

Conduct your meet and greet sessions every day, so that your pets keep getting familiar with each other. Reward them with their favorite treats when they’re together. Let your cat leave the room if he/she wishes, but do not allow your dog to give chase. It’s best if you can bring each session to an end before either one gets upset or aggressive. 

Once you’ve had a series of short meet and greets and you see that your dog and cat are getting along just fine, it’s time to let them loose under your supervision. Still keep your dog on a leash, but let it drag on the floor. This way you can keep him/her from chasing after the cat by stepping on the leash. If things get tense, return to the initial introduction steps until things calm down again. Be patient while repeating the process, making sure that your cat has 24/7 access to his/her dog-proof sanctuary room, just to be safe.  

Being realistic, you will need to supervise all interactions between your cat and dog for the next few weeks and perhaps longer. So that your cat feels safe being in other rooms of the house, make sure that you have shelves or tall pieces of furniture that your cat can jump up on to get away from your dog if necessary. It will be quite a while before your dog and cat can be trusted to be alone in the house together without supervision. So, proceed cautiously by keeping them separated when you’re out of the house.