Hi! This is advice from Maddie's Pet Assistant. Hope it helps!
It’s common for cats to adjust slowly to other cats. Continue to implement positive measures to help them gain confidence in their new environment and build trust with the people and animals.
Here are some helpful tips:
- Use positive reinforcement for introductions as long as necessary. Follow the instructions in the links below.
- At first, keep a visual barrier between them for short sessions and keep them as calm as possible. When the animals begin to relax, start to increase the time they spend near each other.
- Next, advance to barrier-free visits. If problems arise that cannot be corrected quickly and easily, resume the use of a barrier.
- Once your cats have had several, relaxed, barrier-free meetings, you may begin very short unsupervised visits, gradually allowing them more time together.
Note that a medical problem, such as pain or illness, may be the cause of your cat’s fearful behavior. Make sure he/she is eating and drinking, urinating, and defecating, and consider taking your cat to a veterinarian to rule out any medical reason behind this behavior
If you feel at any time your cat’s behavior around your resident cat is worsening, please seek the help of a qualified cat behaviorist or trainer who uses rewards to get results, or your veterinarian.