County and city animal shelters give mixed reviews on microchip technology that reunites pets with their owners.

Although the process is expected to save time and money for the shelters, some question the time and efficiency of chip scanning. The point may be moot, however, as microchips are becoming the tattoo of the 1990s for identifying pets, shelter managers said.

Three companies market microchips, which veterinarians implant just under an animal's skin between the shoulder blades.

AVID of Norco, Calif., InfoPet Identification Systems Inc. of Burnsville, Minn., and Schering-Plough Animal Health of Union, N.J., provide 800 numbers for shelters to call when they detect an implanted chip. The 800 numbers connect the shelters to national registries of owner contact information.

The AVID chips cost $6 each, which includes a bonus number of chips with the first order that shelters place. InfoPet's chip costs $5.95, and Schering-Plough's HomeAgain chip costs $8.25.

The chips also come with collar tags preprinted with the 800 numbers because scanners, which are distributed free to vets and shelters, may not detect all chips.

The AVID scanner detects the AVID and Destron chips. The InfoPet and Schering-Plough scanners detect the Trovan/InfoPet, AVID and Destron chips.

InfoPet's scanner, which debuted in early 1997, reads only the InfoPet chip. It detects the presence of other chips but doesn't read them.

InfoPet is negotiating with the other companies to produce a universal reader that reads all chips. Without the deal, the scanner's read performance on other chips will be inefficient, said Wayne Culberth, vice chairman of InfoPet.

AVID Pettrac gives its scanners to inner city shelters because they do so many scans. The company also distributes scanners to shelters that contact them. It's been a gradual rollout, a company spokesperson said.

Since the beginning of 1996, Schering-Plough has distributed its universal scanner that reads all chips, said Helen Guempel, product assistant for the HomeAgain chip.

Schering-Plough has facilitated more than 6,000 recoveries and implanted chips in nearly 175,000 pets since January 1997, she said.

Shelter workers also worry about chip reliability. Proper scanning technique dictates moving the scanner in a figure-eight pattern across the pet's fur. Read distance for the scanners is just a few inches from where a chip is placed. However, improper scanning or chip movement within the animal can make shelter employees miss the chips.

In one example, a shelter received a dog with an amputated front leg. The chip was not detected in a regular scan because it had migrated to the stump.

Annual scanning costs at the Humane Society of Tennessee Valley were estimated at about $1,400 for the 16,000 animals that were scanned at least twice, said Vicky Crosetti, executive director of the shelter. Although the cost is high for the shelter, scanning must be done because the companies and vets are investing in microchipping, she said.

Some shelter administrators have voiced concerns about the accessibility and security of contacting national registries. This, like scanning, also takes valuable shelter time. Employees must call one of the registries every time they have a positive scan.

The American Kennel Club, which maintains a registry for Schering-Plough's HomeAgain chip, sometimes refuses to give out names and phone numbers, but it does contact the owners.

Shelters that implant chips in animals have found ways to recoup the costs. Fort Wayne, Ind., and Palm Beach, Fla., shelters have instituted microchip programs. From January through September 1997, Fort Wayne Animal Care and Control has implanted chips in 1,199 animals, 156 of which have been returned to the shelter and subsequently reunited with their owners, said Belinda Lewis, Fort Wayne director of animal control.

Although an overwhelming majority of owners reclaim their microchipped pets, there are some who refuse, she said.

The Fort Wayne shelter also implants chips in animals caught on the street. The staff can implant a chip in an animal in about eight minutes but also spends time educating people about the chip, Lewis said.

The adoption fee was increased $10 to compensate for the additional time and expense, and fees for reclaimed pets were also raised, she said.

Animals at the Fort Wayne shelter are categorized as either high risk--those that keep returning to the shelter--or low risk--prescreened adoptees or pets that have good caretakers and therefore don't use as many shelter resources.

"If you're not chipping the high risk pets, then the program won't pay off for your community because chipping saves animals' lives and decreases the amount of time that they stay in the shelter," Lewis said.

At the Palm Beach County Animal Care and Control Division, chips were implanted in about 3,500 animals from October 1996 and August 1997, and in close to 7,000 animals during the past two years. Of the 3,500, 300 animals have been recovered via microchips.

"We're still not using universal scanners as we have found the individual product scanners to be more effective," said Dennis Moore, Palm Beach County shelter director.

Animal shelters in Palm Beach County implant the InfoPet chip in adopted animals and any animal reclaimed at the owner's request.

InfoPet has donated chips that are used to implant animals going to low-income homes. The shelter also retains records on high-risk animals through its own database.

"The fact that we've found 300 chipped animals means that chipping is paying off. Tattoos fade," Moore said.

"If I had my way, I would require owners to put some type of identification on their pets because if we find a chip in them in the field, then we can find the animal on the database. Our costs rise dramatically if the animal has to be brought in," he said.

The Humane Society of New York recently implemented a chip implantation program for all adoptable pets.

The shelter uses the AVID microchip and maintains a database of pets up for adoption. The adoption price has not been raised because the chips were bought in bulk from the company and underwritten by donations to the shelter, said Sandra DeFeo, co-executive director of the humane society.

The trend of microchipping has been growing slowly. But judging from public feedback and the growing number of animals put down each year, it's clearly a worthwhile venture, DeFeo said.

The Montgomery County, Md., Humane Society estimates that one dog per month is found with a microchip, said Heather Bancroft, director of humane education. The shelter uses the AVID scanner to check for chips in about 15 to 20 pets per day.

"A collar and tag is still the best way to reunite lost pets with their owners," she said. "So far, I haven't heard of any plans at the shelter to chip adoptable pets."

The American Humane Association issued a report on microchips in early 1997 after conducting field tests on universal scanners. Based on the tests, it found problems with the scanners, including tuning malfunctions, software difficulties and low battery charges.

It advised shelters to adhere to the manufacturers' instructions, test known microchip's frequently to ensure proper scanner functioning, and do multiple scans of each animal to ensure that microchip's are not overlooked.