Guest Houses
Chiang Mai

Most Guest Houses only publish their daily rate, but most of them
also have a monthly rate.  Call them for their Monthly Rate

I can personally recommend these 2 Guest Houses
Don's Life In Thailand (Chiang Mai)

Seven Senses Guesthouse  
Chiang Mai • Show map
This boutique hotel is located in Chiang Mai, within a 10-minute drive from
the famous Chiang Mai Night Bazaar. Offering Thai-style rooms, it also has
free Wi-Fi and spa services. More

Kamala's Guesthouse
Chiang Mai • Show map
A 5-minute walk to Sunday Walking Street on Thapae Road, Kamala's
Guesthouse offers clean and comfortable rooms with air-conditioning and
free Wi-Fi.

                      Pets allowed Guesthouses

There's not many Guest Houses or Hotels that allow pets.  I was able to find 4
(listed below).  You would probably have better luck renting a Condo as
these are privately owned and the individual owner would make the decision.
Srikum House - CLICK HERE
For a list of other Guest House in Chiang Mai  CLICK HERE