When Frances Adams of Northwest Washington last month received the city's annual notice for renewing the license for the family pooch, she discovered what she considers the doggonedest case of canine sex discrimination.

City licensing officials, following through for the first time on a 1979 law passed by the City Council, this year hiked the licensing fee to $25 for unspayed female dogs. That amount is five time the $5 fee for unneutered male dogs and five times the fee for spayed female dogs.

In an angry letter to the city's licensing department, Adams said she refused to pay for an obvious case of "sexist prejudice," especially since the dog in question, a chaste cocker spaniel named Taffy, is kept alone in a fenced yard and apparently has no intention of contributing to Washington's canine birthrate.

"If you are charging more for fees for dogs who can reproduce," Adams wrote, "you should logically increase the fee for non-neutered male dogs who can impregnate a bevy of bitches in no time at all.

"Perhaps dogs need an ERA," she said.

The purpose of the law, with the licensing-fee differential, is to control the city's growing animal population. But the law puts the burden of canine contraception on the females, which may seem odd since the law was passed at a time when the majority of the council was composed of females and since the council recently passed a bill to make the city's sex laws for humans gender-free.

"It's kind of a chauvinistic attitude, I guess," said Dr. Edward Morris, a Northwest Washington veterinarian. "It goes back to the old attitude that birth control is the female's problem. To be quite fair, it should be required for both."

Diane Bettien, an animal technician with the city's dog pound, said dog owners are more reluctant to put their male pets under the knife because "people think the dog won't be as aggressive or as mean. The watchdog loses his virility."

Actually, some veterinarians said there may be some medical truth to that. Dr. JoAnne O'brien of Collins' Veterinary Hospital in Northwest Washington said that male dogs generally experience more adverse physiological reactions to being "fixed" than do female dogs. CAPTION:

Picture, A $25 license fee is required for Frances Adams' cocker spaniel, Taffy. By James M. Thresher -- The Washington Post