Creature Comforts : Right Pet Entrance Can Make an Open-Door Policy a Success While Shutting Out Unwanted Rascals

Pet doors--many of them bearing new and improved safety devices--are giving dogs, cats and their owners greater freedom to go about their business.

“I have three cats, and I was letting them in and out all night,” said Susan Christopher of Garden Grove, a pet door owner of two years. “Now I don’t have to get up 20 times during the night.”

Pet doors tend to be particularly popular in households where, due to the demands of work or school, pets are left alone for hours at a time.

“Both my husband and I work and, rather than have indoor or outdoor dogs, our three dogs are free to come in and out of the house,” said one Irvine resident.

There is a flip side to this open-door policy, though.

Most pet doors can’t prevent unwanted animal visitors from checking in and out. A number of pet door owners report occasionally finding cats or dogs other than their own dropping in for a visit--or dinner.

Cathleen Mattie of Laguna Beach installed a cat door in a new apartment only to have the cat belonging to the previous tenant make use of the feline-friendly opening.

“He comes in and eats the food,” Mattie said. “He visits maybe once or twice a month.”

And, while not a convenient entry, it is a potential one for unwanted human visitors willing to get down on all fours and work at it.

“It’s phenomenal what small openings people can get through,” said John Robertson, police chief for the city of Orange. “I’ve taken (burglary) reports where people told me the pet doors were their system if they got locked out so--surprise, surprise--they got burglarized that way,” Robertson said.

Of course, pet door makers are trying to make their products smarter than the neighbor’s pet and the local burglar.

The bottom line is that pet doors are not for every household. One factor to take into consideration is how difficult access by unwanted visitors will be; another is one’s personal level of security consciousness. Those things need to be weighed against the advantages of Fido and Tabby being able to let themselves in and out.

Committing to a pet door is a little like committing to your pet: There’s often no turning back. Once installed, many pet door styles leave a permanent hole in your human-size door.

That’s why panel-like attachments designed specifically to slide into glass doors have increased in popularity.

“It’s the most popular pet door at my stores,” said Lee Hein, manager of Pet Care Co. stores in Huntington Beach and Newport Beach. “It’s easy to put in, and the dog is generally let out through the sliding glass door anyway, so it’s easy to train the animal to use it.”

This panel door attaches to the main sliding door and locks into place, preserving the integrity of the original door.

And if you decide to do away with the pet door, the glass panel extension can be removed, leaving little more than a few drill marks on the original frame.

More traditional pet doors are installed permanently into a door, wall or window.

These types are typically sold as a kit consisting of a plastic frame with a clear plastic or plexiglass door designed to swing back and forth so animals can push in and out of the home without opening the main door.

Most professionally designed pet door kits run between $20 and $300 and take about an hour to install, according to Alan Lethers, owner of San Pedro-based Patio Pacific, a mail-order firm specializing in pet doors.

The frames can be fitted to window screens, walls or wooden doors by cutting or sawing a space for the flap and attaching the frame with nothing more sophisticated than a drill.

The flaps are replaceable and cost about $20.

The simplest pet doors are made for window screens and cost about $20, Hein says. Pet entryways suitable for walls and wooden doors can run between $20 and a little more than $100, depending on the size of the pet opening.

For those worried about neighborhood cats or even wild animals slipping through their pet doors, there are several systems available designed to reduce the likelihood of such visits.

Pet door systems activated solely by means of a magnetic collar worn by the animal start as low as $50 and go up to $129, with the true creme de la creme of pet doors being an electronic-powered aperture that runs a little less than $300 and can be tied into a home security system.

The electronic door responds only to an animal wearing an ultrasonic flea collar. The door contains a pair of microphones that pick up the signals emanating from the collar, forcing the door to slide up or down for a preset length of time--not unlike the electronic doors featured in the opening of the TV series “Get Smart.”

The electronic door is windproof, and even the smartest wild animal can’t finagle a way around it, as they can with some of the less expensive magnetic-lock doors, said Lethers of Patio Pacific.

Pet doors can be bought at most pet stores and home supply stores. There are a number of manufacturers in the field, and it’s likely that most people will find a door to suit their needs, Lethers said.

While it is possible to design and install your own pet doors, professionals in the field don’t recommend it unless you are very handy.

“It’s hard to make a flap that works well,” Lethers said. “Flaps are molded to seal well, and they are really hard to make by yourself. Basically, people cut a piece of carpet or something like that, but it never seals well. And people usually put nails across the top, and that just looks tacky.

“It’s just a lot easier to buy a door,” Lethers concluded.

And no one needs to tell Christopher the perils of do-it-yourself doors.

“We had little vents on the side of the garage, and we had taken those out so the cats could come in and out,” she recalled. “Then skunks started coming into the house with the cats and eating their food.”

Fortunately, after dinner, the skunks had the courtesy to go right back out again.