I got black toenail of my left big toe and partially of the right from a single run in too-short shoes two summers ago. Took nearly a year for the toenails to grow out completely and be normal again, though they never fell off completely. It was painful at first, then stopped being painful and just looked like hell. I now buy running/walking/hiking shoes 1/2 size larger than my "street" shoe size and have not had a recurrence.
Fortunately the second toe toenail will grow out a lot faster than the big toenail does! You just might need a half-size larger shoe, tho, V. None of your toes should touch in front when you are pointed downhill. Are your second toes longer than your big toe, by chance?
Emily
Emily
2011 Jamis Dakar XC "Toto" - Selle Italia Ldy Gel Flow
2007 Trek Pilot 5.0 WSD "Gloria" - Selle Italia Diva Gel Flow
2004 Bike Friday Petite Pocket Crusoe - Selle Italia Diva Gel Flow