Introducing A New Dog to Your Cat
Introduce Gradually continued...
6. The final step is to allow the animals to interact more freely. Begin with short periods of time together, especially after the dog has been well exercised. Keep a close eye on the dog. To be absolutely risk-free, muzzle the dog until you are confident that he will not harm the other pet. As you gain more confidence, give the animals more time together. Make sure there are plenty of escape routes and safety refuges for the small pet, such as kitty condos, shelves and areas behind furniture to which the dog cannot reach.
7. We’ve heard numerous anecdotes of dogs who were fine with a small pet until the animals were left alone together. We recommend that you keep the dog crated or otherwise confined away from the other pet during your absences. It is not sufficient to keep the small pet caged and the dog loose. The dog could harass and frighten the pet, or even break into the cage.
WebMD Veterinary Reference from ASPCA Virtual Pet Behaviorist

