New Feline Introduction (Feline)
Introductions occur when a pet parent integrates a new cat into a home that already contains a cat. Intercat aggression throughout the lifetime of the cats can significantly increase due to aggression during introductions.
Common names: Integrating the new cat, New cat introductions.
Scientific names: Integrating the new cat, New cat introductions.
There is no age, sex or breed predilection. Mature unneutered pets may complicate the introduction process.
Clinical signs (primary, most to least frequent, scientific term, synonyms)
There are no clinical signs in the pet.
Causes (scientific, common term)
New cat introduction complications result from normal feline behavior.
Organ systems affected (most to least affected)
There are no organ systems affected.
Stepwise introductions are indicated for all new cat introductions into households with cats. Improper introductions can lead to intercat aggression throughout the lifetime of the cats, elimination issues and stereotypic behaviors.
If aggression is noted at any step during a new introduction, action should be taken to move back to the previous step. Timelines introduced below assume minimum aggression. If aggression is noted, the timeline can significantly increase.
Step 1. When possible, the resident cat (RC) should experience a change in routine about a month before the introduction. For example, access to certain rooms in the home should be limited, food dishes moved, and interactions with the pet parent decreased.
Step 2. The introduced cat (IC) should be housed in a room with water, food, a scratching post, toys and a litter box. The room should not be a room where the pet parent spends the majority of time or where the RC routinely spends the majority of time. The door should have a gap at the bottom of about half an inch to one inch to allow paws through.
The RC's schedule should remain as close to normal as possible. Opportunities for interaction by the door should be encouraged with treats placed by the door on either side, as well as the use of toys.
After a full 24 hours, switch a piece of bedding, affording the cats more opportunity to investigate odor.
Step 3. If no aggression is noted after three days, cats should be switched for a few hours a day so that the IC is now in the larger space and the RC is in the space where the IC resided. This will allow the cats to further investigate odors.
Step 4. If no aggression is noted after three days, the solid door should be replaced with a temporary screen door so that the cats now have visual contact. Cats should be able to move out of visual contact if desired. Observations of aggression should be noted. Treats should be dispensed on both sides of the screen to encourage interaction.
Step 5. If no aggression is noted after two days, short interactions in the same space should be conducted. Equipment needed: a squirt bottle and loud noisemaker (such as a penny can) to disengage aggression, should it occur. Interactions should be short, and observations of aggressive behavior should be noted. If aggressive behaviors are noted, the next session can be extended. If either cat continually runs and hides, return to step 3 for three to four more days.
Step 6. Full integration of IC into home. Litter boxes (one for each cat, plus one extra), food and water should be in the open. Hiding places, with easy escape options, should be readily available.
Excessive fear or moderate aggression displayed by either the introduced cat or resident cat that cannot be managed by pet parents may benefit from consultation with a certified applied animal behaviorist (CAAB; www.certifiedanimalbehaviorist.com), a diplomate of the American College of Veterinary Behavior (ACVB; www.dacvb.org), or another qualified professional.
Careful attention to detail is key to any successful behavior-modification program.
Following a stepwise process will likely lead to successful integration of the new cat.
Hetts, S. Pet Behavior Protocols. Lakewood, CO: American Animal Hospital Association,1999; 133-151.
Levine, E., Perry, P., Scarlett, J., Houpt, K.A. Intercat aggression in households following the introduction of a new cat. Applied Animal Behaviour Science. 2005; 90:325-336.
Emily Weiss, PhD, CAAB
Steven Hansen, DVM, MS, MBA, DABVT, DABT
© 2007. The American Society for the Prevention of Cruelty to Animals (ASPCA)