Separate the puppy from your cat by placing them in adjacent rooms separated by a door. Make sure you provide your cat with the basics: litter box, food and water station, toys, perches and such. In this manner, both your new puppy and your cat will be able to get used to hearing and smelling one another without the risk of direct interactions during this sensitive time.
Placing a blanket or towel with your puppy’s scent in the room with your cat will help ease the transition. You can also place a blanket or towel with your cat’s scent in the room with your puppy. Using pheromone products like Feliway will also help ease the transition for both your cat and your puppy, respectively.
During this time, be sure to spend time bonding with each pet individually. Give both animals time to become relaxed and comfortable in their individual areas. Once both pets seem relaxed with the current situation, switch their positions.
Allow your puppy to occupy the room where your cat has been and your cat to occupy the room your puppy has vacated. You can switch rooms several times during the introductory period.
Once both puppy and cat are comfortable with the scents and smells of one another, it’s time to introduce them face-to-face. Keep a barrier between them initially. Place your cat in a large open-sided carrier or use a baby gate the cat cannot get over, under, or through. Keep the puppy on a leash during the initial encounters so that you can supervise and direct his activities until you feel comfortable that both pets will tolerate one another.
Reward your puppy for being calm and quiet when near your cat. Avoid allowing your puppy to chase, harass or otherwise torment your cat. The goal is to teach your puppy that he is rewarded for good behaviour when your cat is around. Bad behaviour should not be encouraged or allowed to occur but should not be punished if lapses do occur accidentally, as this may create unwanted responses and issues between your puppy and your cat.
In most cases, with time, your new puppy and your cat will come to accept each other and may even become friends. However, each situation is different and you should assess the reactions of both animals before you allow them to remain together unsupervised.
As in all situations, be sure your cat has perches at [human] eye-level or above where he can escape from the attentions of your puppy if necessary. Your cat should also have a private area where the puppy is unable to follow for times when he feels the need to be alone.
And don’t forget to spend plenty of alone time (without your puppy present) snuggling or playing with your cat.