Choosing before you know the sex is more common than it sounds: a litter is promised, a shelter dog is reserved, a name is agreed at the kitchen table weeks early. The names below are the ones the records show going both ways.
Unisex here is a measurement, not an impression. A name qualifies when the animals carrying it were sexed between 35% and 65% female across a sample of five or more — so nothing on this list was chosen for sounding androgynous.
The ones that surprise people
Charlie and Riley read as male to most people and measure almost exactly even. That is the value of counting: a name's reputation and its use are different things, and only one of them is in the data.
Every count on this site is a tally of real registrations: pet licences and shelter intakes published as open data by New York, Seattle, Austin, Montgomery County, Cambridge, Zurich, Basel and three Australian councils. Popularity here is the average share a name holds across those registers, so a name common in a small city is not buried by one common in a large one. Nine of the eleven sources are North American, so read the ordering as naming in those places rather than worldwide.