The penalty for having an unlicensed cat in Montgomery County is $25, not $250, as reported yesterday. The $250 fine is for having a cat without a current rabies inoculation. The county licensing law, which will be enforced beginning next month, does not apply to cats whose owners live in Rockville, Gaithersburg, Chevy Chase Village and other municipalities. The rabies-inoculation law applies throughout the county, however.

Montgomery County's cat owners, who had faced $250 fines if their felines were spotted without license tags after tomorrow, won a reprieve yesterday when county officials said they will not start enforcing the new licensing law for another month.

The controversial law, condemned as vague and unworkable by the county's veterinarians, was passed by the county council in June in an effort to fight the rabies epidemic that first struck the county in 1982. Since the epidemic began, four cases of cat rabies have been reported in the county. Although county law already requires that the estimated 100,000 cats, like dogs, be innoculated against the disease, the new measure sought to enforce the innoculations by requiring proof of vaccinations before issuance of the licenses.

The licenses and tags, which look like dog license tags, can be obtained by mail or in person from the county's animal shelter. They cost $5 for spayed or neutered cats, and $10 for cats that have not been altered.

Officials said the licensing is going smoothly and rapidly, although telephone lines at the shelter on East Gude Drive in Rockville have been clogged with calls from people asking questions. Animal control director Thomas Ferguson said the response has been "positive."

He acknowledged there had been complaints but said they diminished substantially when the county abandoned a fee schedule that charged cat owners more to license unspayed females but not unfixed males.

"We aren't running a police state here," Ferguson said. "Our concern is to protect the public health and welfare."

But Linda Buel, owner of a Rockville pet hotel, said, "The whole thing is stupid. Rabies control and licensing are two separate issues." She led a petition drive to overturn the licensing legislation, but the effort fell short of the 16,817 signatures needed to have the issue placed on the November ballot.

The county's association of veterinarians, which supports anti-rabies measures but says the new cat licensing law is too vague to be useful, announced yesterday that it will not inform county officials of cats that are not licensed.

"We don't want people to think we are going to be turning them in," said association President Larry Geible, a Gaithersburg veterinarian.