(From WRO Newsletter, As Reprinted in the Aug/Sep ‘96 CRC Newsletter)

Considering adding another dog to your home? Adding a new puppy or dog to a household where dogs and cats already reside takes time and effort to be successful. Jo Ann Eurell, DVM University of Illinois College of Veterinary Medicine, Urbana Illinois, has a special interest in animal behavior and she offers a few suggestions to make the transition a safe and smooth one.

First, assess your household's current pet status before you add another animal to the mix. If you have an aggressive dog, the nature of the aggression must be identified and managed. Consider the physical condition of your current animals. For example, an older arthritic dog may be less tolerant of a puppy's boisterous behavior.

Ensure that proper facilities are in place to accommodate a new animal, such as a separate pen or room, or better yet, a crate. Food bowls and toys can also pose problems. Puppies are used to sharing food with their litter mates but an older dog may not appreciate this. Feed the animals separate bowls in separate areas. Dr. Eurell notes that sharing the same water bowl is usually not a problem. Until the animals learn to share don't let the new puppy play with the older dog's toys. Have a toy on hand just for the new puppy.

To ensure that your household pets stay healthy it is important to have the new puppy examined by a veterinarian as soon as possible. (Depending on the breed, a puppy should be 8 to 12 weeks old before it is removed from its mother and litter mates). Some owners head straight to their veterinarian after picking up a puppy from a breeder or humane society. A veterinarian can examine the animal and reduce the threat of disease transmission to existing pets, notes Dr. Eurell.

Take the initial introduction slow. "Allowing the new puppy to bound out of the car and into the dog's yard is a big mistake," Eurell says. "All dogs should be on leashes in case things get out of hand .... You are in control." The introduction phase can take hours, days, weeks or even months depending on the situation. In multiple-dog households, introduce the puppy to one dog at a time. "The dogs need a chance to establish the pack's dominance hierarchy," says Eurell. "Usually the oldest or largest animal will reign as the 'top dog' of this hierarchy."

The most common mistake owners make is to leave a new puppy alone with the established pet or pets, "Never leave a new puppy alone with these pets during the get-acquainted stage," says Dr. Eurell, "especially if the established dogs are older. "Puppies don't understand the pecking order and they haven't learned the necessary submissive skills. The older dog may give signals of dominance but the puppy doesn't know how to read them. This situation often results in injury with the older dog biting or pinning down the younger animal."

The puppy needs to be of comparable size before it should be left alone with the pack," It's up to the owner to decide when that time is right. "Older dogs recognize the puppy as an infant. They will discipline the youngster until they can't take it anymore. That's when the tolerance level drops and aggression escalates." says Dr. Eurell.

It's important to provide equal attention to both the new and established pets. This includes one-on-one time, appropriate exercise and play time, and lots of love. If it appears that the new animal is getting all the attention, the older dog may become jealous and redirect its jealousy aggression toward the puppy and cause injury. "Animals are very intuitive. You may notice that the dog will put its body between you and the new puppy or try to ‘steal' your attention from the puppy.

Introducing the puppy to a cat household should be done just as cautiously. The same rules apply. Supervise the interaction and closely observe the cat's body language. Much of the acceptance will depend on the cat's previous experiences with dogs.

The introduction of an adopted dog to an adult cat needs to be on the cat's terms. Again, be ready for problems. Most cats are easily stressed by the presence of a dog. They may tolerate the behavior for a short while, then exit.

Unhappy cats may show their disapproval with abnormal behavior such as urinating in places other than the litter box.

For the most part, dogs and cats adjust to new pets without incident. However, since the consequences of a problem can be severe, it is wise to assume that a dog or cat could react adversely and take proper precautions.

Dr. Eurell recommends reading How to Raise a Puppy You Can Live With, by Clarice Rutherford and David Neil; or Second-Hand Dog; How To Turn Yours Into A First-Rate Pet by Carol Lea Benjamin.