This is a poem that I wrote at prep school, around the age of 12-13. Back then I wrote quite a few poems about WWI, one of which won the school’s poetry prize but that poem is unfortunately lost. In any case, here is one written about horses.
Horses in the First World War
Trudging through the blood and gore.
Leaping over barbed wire fence
Diving into waist-high trench.
Watching all his friends get shot
Watching bones and bleed all rot.
Wretched skies filled with bombs.
Enemy trenches drawing near
Horse is only one left here.
Bayonets poke at skin
Horse knows that death will win