How to introduce a new pet ‍into your household

Let’s say Santa brought you a new cat or dog for Christmas and now you have multiple pets vying for your time and treats. 

By Malcolm Mayhew
Virbac Copywriter

While the addition of a pet to a household is always a celebratory event, sometimes conflicts can arise between the new pet in town and the pets that have long established their residencies.

Here at Virbac, we understand the stress these changes can cause - for pets and for owners - when not everyone in your pet household is getting along. We want to help make this process as seamless as possible so we have launched a two-part blog series featuring tips on introducing a new pet into your home. This week, we’ll discuss cats; a blog post specifically about dogs will come next week. 

Cats are solitary and highly territorial creatures that often require weeks or months to adjust to changes in their environment and lifestyle, according to the Animal Humane Society. A kitten’s adjustment period can take 2-4 weeks, an adult cat’s up to 4-6 weeks. 

To help smooth the transition, follow these steps provided by the Humane Society:


Create a room specifically for your new cat. Keep them isolated from your other cats and give them their own food, water, bed and litter box for at least one week, or until your veterinarian has examined them and screened them for contagious diseases. “It is important to let your veterinarian know you have other cats in the home and to ensure your new feline friend isn’t carrying infectious diseases, such as feline leukemia and FIV, that may affect the health of your current residents,” says Genna Mize, DVM, a consulting veterinarian at Virbac.

Keep your new cat inside his/her room, feed your cats on opposite sides of the same door. Meal by meal, push their bowls a little closer to one another and then finally crack open the door, allowing them to see and smell one another.

Let your new cat explore. Put your resident cats in a separate room and let the new cat in your household roam freely and get accustomed to the scent of your resident cats. 

Introduce the new cat but monitor behavior and limit their time together. It’s OK if there’s a bit of hissing and crouching initially; that’s to be expected. But you want to avoid letting them establish a pattern of aggressive or fearful behavior; let their first encounter be a short one.

If they fight, separate them and go back to step 1. If a fight breaks out, separate them immediately by distracting them and putting the new cat back into the space you created for them in step 1. Don’t try to pick up the cat while they’re fighting; you could get bitten or scratched. To help support your cats in this stressful environment, Dr. Mize suggests ANXITANE® (L-Theanine) Chewable Tablets, which helps keep cats calm and relaxed. 

Continue to monitor their behavior. Be cognizant of any tension or aggressive behavior. If one cat is staring at or fixated on another, offer him/her a treat. This will distract them from one another and also teach them that good things happen when the other cat is near. 


  • Understand the introduction of a new cat or kitten to a household is as big of an adjustment for them as it is for your resident cat. Assure your resident cat by spending a bit more time with them. 
  • Some cats bond easily, others not so much. Know that the new cat and resident cat may spend their lives hissing at one another, or they may instantly bond. It could go either way. 
  • If, after a month of following these steps, your new cat and resident cat are acting aggressively toward one another - terrorizing or causing injury - long-term success may be unrealistic. Rehoming one of the cats or keeping them separated permanently may be your best option to keep everyone safe.