Edit 5/1/11: This bill did not pass the House before the legislative session adjourned; now dead.
Idaho S1143 would, among other things, prohibit municipalities from defining dogs as vicious or dangerous based on their breed.*
25-2814. LOCAL REGULATION. The provisions of this chapter shall establish as state law minimum standards and requirements for the control of dogs and to provide for certain state crimes for violations of such minimum standards and requirements. Provided however, this chapter shall not supersede or invalidate existing ordinances of local governments or prohibit local governments from adopting and enforcing ordinances that provide for more restrictive control of dogs, including more restrictive definitions of a dangerous or vicious dog, provided such definitions are not specific to one (1) or several breeds of dogs.
*S1143 does a lot more than this, so it is recommended that you read through the entire bill before determining whether to support or oppose it.
Idaho S1143 may be read and tracked here: http://legislature.idaho.gov/legislation/2011/S1143.htm