Many Washington area veterinarians said they were faced with "mass hysteria" as local dog owners deluged them with demands for free revaccinations after learning that their pets' rabies shots may have been faulty.

A spokesman for Norden Laboratories of Lincoln, Neb., which announced Wednesday that millions of dogs nationally that received Norden products may need to be reinoculated, apologized last night for the confusion. He said the company would send free vaccines, syringes and some support material to veterinarians who can provide documentation on animals that need to be revaccinated.

"This is not a panic situation," said Cecil Metzger, Norden's director of customer affairs. "I'm sorry we haven't been able to better communicate to {veterinarians} that we're going to give them support."

The promise of company support was not enough to calm area veterinarians who were swamped yesterday with angry customers.

"There's mass hysteria out there," said Jeffrey M. Kline of Maple Springs Veterinary Office in Gaithersburg. "People feel cheated. They fear for the life of their animal."

"We were inundated," echoed Bob Cohn, of the North Laurel Animal Hospital. "When I unlocked the doors this morning, the phones were ringing, and they've been ringing all day. I regret having to go in tomorrow."

Not all dogs given the vaccine are at risk, because there are two ways it can be administered, and only one failed a government-conducted test. The vaccine can be injected into a muscle, the established method that is still considered effective, or subcutaneously, just under the skin, the newer procedure that failed.

Norden has urged veterinarians to reinoculate dogs that were vaccinated under the skin because the animals may not be protected.

Some pet owners were demanding free revaccinations even after being told that their pets had received proper inoculations, a request some veterinarians were reluctant to grant. "Some veterinarians are being made to look very greedy and some to be saints," Cohn said. "It's a terrible public relations image for all of us."

Metzger said that the dogs most at risk are those that had never been vaccinated and those that have received only one dose since July 1985. Those dogs should be revaccinated as soon as possible, according to the company.

However, veterinarians were confused yesterday about whether Norden would reimburse them for the costs of revaccinating dogs.

"We are totally perplexed about who's doing what," Cohn said. "We don't know who's going to reimburse us, when, how much and whether they're going to do it in products or in cash."

Cohn said that when he called Norden's representative in Richmond, the representative told him the company "didn't know what they were going to do and would give us a 90-day delay billing."

"I haven't heard boo from Norden Company," Kline said. "And we're not in the position at this point to revaccinate free. Norden hasn't sent us the free vaccines. I haven't received free syringes."

Kline complained about the additional time needed to revaccinate. "It's not just a matter of giving everybody a shot. I usually examine the animal, and I have to write out forms. I only have two assistants, and I have a ton of surgery to do and a ton of very sick animals coming in."

Metzger, Norden's spokesman, said the company would put together by next week a support program, which will include free syringes and vaccine, for veterinarians who can show that they have revaccinated dogs that may be affected. Metzger said the company has set up a hot line for questions from veterinarians.

"Talk is cheap," Cohn said. "I want to hear from the company before it gets published in the newspaper and I get 10 million phone calls."

Cohn and other veterinarians said Norden should offer free rabies clinics and compensate veterinarians for revaccinating dogs or supply the veterinarians with free syringes, vaccine and funds necessary to pay staff overtime for the increased paperwork.

"The Norden company has messed up," Kline said. "We pay them a lot for our vaccinations. They've led us astray. Norden has to take the responsibility."