Has an International Rugby game ever ended 37-0?
It has. 37-0 has been a International Rugby final 2 times in 2,783 games. The first was England beat France on January 28, 1911; the latest was England beat Italy on September 6, 2019.
That makes 37-0 the 347th most common final score out of 844 that have ever occurred in International Rugby. One point away, 38-0 has happened 2 times and 37-1 has happened never. At one point the score disappeared for 108 years, between 1911 and 2019.