Drowning

Drowning was a potential cause of death that would occur when an individual was submerged in water for to long.

Probably since drowning isn't particularly graphic to actually display, there have been quite a few instances of ponies, humans and dragons nearly drowning to death throughout the franchises run, possibly more than any other cause of death. Some instances portrayed as lighthearted, while others were rather dire.

Generation 1

 * In "Rescue at Midnight Castle", fell into a large river when she failed to cross a rickety bridge, and Megan jumped in after her. The two nearly drowned, but were saved by the Seaponies.
 * In "Escape from Catrina", Baby Moondancer falls into a small stream and nearly drowns, but was saved by the Seaponies.

Generation 4

 * In the manga story, "I Love Rarity!", Twilight nearly drowned while the girls were on vacation, but was saved by Rarity.
 * In "Gauntlet of Fire", nearly drowned after being hurt by a Sea Worm, but was saved by.
 * In My Little Pony: The Movie, the main cast nearly drown after being sucked into the Lotus Fountain, but were saved by Princess Skystar.
 * In Equestria Girls: Spring Breakdown, after the Lux Deluxe crashed, the passangers faced the very real possibility of drowning in the sea, but instead managed to find salvation on the Magic Island.
 * In, a young nearly drowned during a storm in the hottest dang summer, but was saved by.