"Our dog has only one ear."
Chinese is specific only when it is needed to be (certainly there are limitations). The Chinese sentence of Duo above also applies in the case where "we" have more than one dog and all of them have only one ear, i.e. "Our dogs have only one ear." It is certainly a bit odd but is nonetheless completely correct. The number of dog(s) is not mentioned and is not important as long as it is/they are our dog(s). You need a classifier when you talk about the quantity, whether you specify it, approximate it, or inquire about it.
One of our dogs has only one ear.
A few of our dogs have only one ear.
How many of our dogs have only one ear?