This appears to be a case of “the county did it, so we should too.” California state law prohibits municipalities from passing breed-specific laws, except for breed-specific mandatory spay/neuter.
Although it is a done deal, if you wish to contact the mayor and council, you can find their contact information here: http://www.fontana.org/Directory.aspx?did=3
Fontana enacts new pit bull law
Jim Steinberg, Staff Writer
Posted: 08/10/2011 06:32:02 PM PDT
FONTANA – The City council, by a 5-0 vote, has passed an ordinance requiring all owners of pit bulls and pit bull mixed breed to spay or neuter their dog before it reaches the age of four months.
The ordinance mirrors a law San Bernardino County enacted several years ago and adopted by many area cities.[…]
Full article retrieved 8/11/11 from http://www.sbsun.com/news/ci_18656650