It is mostly condos. There are 36 condos, owned mostly by Americans and Ticos and there is lots of common area to walk your dog. One of the owners has 2 small dogs. Those condos are 3 bedroom. There are 8 townhomes, 2 bedroom, but no private yard. One is most definitely open to a yearly rental and they love cats, so I'm sure they would accept a dog. Then there are a 3rd set of condos, mostly unsold, and probably not available for rent.
You are correct, there are only 4 houses built and only one is available for rental on a weekly, not long term basis.
Generally, having a dog here will not be a problem. Owners who come here for long stays even bring their dogs from the states.
I wouldn't even begin to guess what rents might be in the condo's, but I'm guessing about 2K per month. In the townhomes, probably about $1300 or $1400.