Specifically Havanese dogs.
Milk and dogs in general do not agree – most dogs tend to be lactose intolerant. A small amount won’t harm them, but why risk them getting diarrhea or vomiting. However plain low-fat yogurt in small doses (i.e. 1 or 2 tsps) is good for gastro problems, especially gas, at least in greyhounds. I don’t know specifically about Havanese dogs though.