Answer. By all means. The bases for terminating a tenancy are found in ORS 90.630; there are several. It provides that “…the landlord may terminate a rental agreement that is a month-to-month or fixed term tenancy for space for a manufactured dwelling or floating home by giving to the resident not less than 30 days’ notice in writing before the date designated in the notice for termination if the resident. Among others, the following are listed:
- If the resident violates a law or ordinance related to the resident’s conduct as a resident, including but not limited to a material noncompliance with ORS 90.740 (Resident obligations); and
- If the resident violates a rule or rental agreement provision related to the resident’s conduct as a resident and imposed as a condition of occupancy.
The definition of a “law” is a state statute. The section of the landlord-resident law (ORS 90.100) does not expressly define “ordinance” but does define “building and housing codes” to include “…any law, ordinance or governmental regulation concerning fitness for habitation, or the construction, maintenance, operation, occupancy, use or appearance of any premises or dwelling unit.”
Elsewhere, a good definition of an ordinance is the following:
An ordinance is a law enacted by a municipal body, such as a city council or county commission (sometimes called county council or county board of supervisors). Ordinances govern matters not already covered by state or federal laws such as zoning, safety and building regulations. (See, http://www.lectlaw.com/ def2/ o045.htm)
So, do you need to expressly provide in your rules or rental agreement that residents must obey all state laws and local ordinances? No. In legal parlance, ORS 90.630 is “self-executing”, i.e. it is effective by its own terms. 
However, if you are using the MHCO Lease or Rental Agreement, the forms contain text that expressly states what ORS 90.630 already provides. This is the “belts and suspenders” approach to park management.
So if a resident has a pet, you want to make sure they comply with all of the local ordinances as well as any specific rules and regulations you may have – even if the rules and regulations are stricter than the local ordinances. In order to avoid unpleasant surprises, I suggest you prepare a separate “Pet Policy” handout for residents, prospective and current, making sure that it correctly states exactly which ordinances you intend to apply, together with all park rules that are not already covered by the applicable laws.
 To be clear, however, if the park is located in Deschutes County, you may not enforce a Jefferson County ordinance unless you have incorporated that ordinance in your rules, either directly or by reference. As I said above, you may impose rules that are stricter than those found in your local jurisdiction, but you have to expressly include them in your rules.
 Note that if you have not been enforcing current laws, ordinances or park rules regarding pets, you may run into some push-back if you have not enforced them previously, e.g. pet size, breed, or number. Certainly, if a resident has one pet, and your pet policy is set at one, you want to make sure that you keep all non-violating residents at that number. In my opinion, your failure to enforce a rule, law or ordinance against one resident who has two pets, does not mean you may not enforce it against other residents with only one, on a going forward basis.
 Out of an abundance of caution, I would identify all the important ordinances, either verbatim or carefully summarized, but make it clear that this Pet Policy is for “informational purposes only”, and is not to be construed as being in lieu of the actual law or ordinance. Always include the citation to the law or ordinance you are summarizing or quoting.