Ws are almost always dog friendly. I also know that the Ritz-Carlton, Liberty, Le Meridien Cambridge, Sheraton Commander, Sheraton Boston, Westin Boston Waterfront, Westin Copley all allow dogs (probably up to 40-50 lbs or so, not that anyone ever weights a dog LOL).

You can google any of the hotels in the Bonvoy portfolio and just add pet policy and it's pretty easy to find. Most hotels will allow a small dog if you ask (and maybe have elite status) even if they officially don't allow it. (Most hotels use certain floors or wings or rooms for those traveling with pets.)