Riverside County supervisors are expected today to approve an ordinance mandating that, with only a few exceptions, pit bulls older than 4 months in unincorporated communities be sterilized for the sake of public safety.

``We tend to see that many owners of pit bulls are not responsible,'' said Supervisor John Tavaglione, who joined his colleagues in a 5-0 vote last month to move the proposed ordinance forward.

The Department of Animal Services broached the issue of restricting pit bull breeding to the board in April, receiving a mixed response.

Many pit bull owners complained that the breed had been ``sensationalized'' and unfairly targeted for criticism. Victims of pit bull attacks, including Beaumont City Councilwoman Brenda Knight, countered that the canines have a vicious streak and physical makeup that make them inherently dangerous.

Woodcrest veterinarian Melanie Verreault told the Board of Supervisors in September that mandatory sterilization would lead to less compliance with county dog licensing and registration regulations. Verreault worried that pit owners would be ``fearful'' of seeking training or medical attention for their dogs out of concern that they might receive citations for not having had the pets spayed or neutered.

Animal services Director Rob Miller noted that 20 percent of impounded dogs and 30 percent of those euthanized at county shelters are pits, which ``historically have very low redemption or adoption rates.''

Under the measure, any pit bull over 4 months old would be required to be spayed or neutered unless an owner can qualify his or her animal for one of the following five exemptions:

   -- the dog belongs to a registered breeder;

   -- is trained for law enforcement duties;

   -- is an ``assistance dog'' for a disabled person;

   -- has been certified by a veterinarian as having a health defect that sterilization          would aggravate; or

   -- is in training and licensed in another county.

In its proposal, the Department of Animal Services defines pits as Staffordshire Bull Terriers, American Pit Bull Terriers, American Stafford Terriers ``or any mixed breed which contains ... any one of these breeds so as to be identifiable as partially of one or more of these breeds.''

A dog owner may request a ``breed determination,'' which would require the county's chief veterinarian or a member of his staff to examine the animal. 

If the dog is designated a pit bull, an owner would have the opportunity to appeal the finding before a county administrative officer, or take the case to court.

Individuals who fail to comply with the ordinance would be assessed fines and penalties, according to county officials. Enforcing the ordinance would occur when a dog is impounded or when it's brought in to be vaccinated, licensed or microchipped.

Numerous pit bull attacks have been reported in the region this year, including on Sept. 22, when as many as five pit-bull-type mix dogs mauled a 2-year-old Colton boy to death in San Bernardino County.

In Riverside County, an 80-year-old French Valley man was seriously mauled by his son's 90-pound Mastiff pit mix in June. In February, a 91-year-old Hemet woman was killed by her two pit bulls.

Supervisor John Tavaglione said in April that he wanted tough regulations targeting owners after learning that an 84-year-old Jurupa Valley man was torn apart by a family pit while sitting in his wheelchair.

If approved, the ordinance will only apply to unincorporated communities, though area cities could choose to use the county measure as a model.