Yes , in every war animals were used and died; but in the modern, industrial wars a huge number of animals were killed. In ww1 and many more during ww2....In fact, even if modern weapons existed, missiles, modern tanks, modern airplanes....The wehrmacht and the russian armies ( and the italian, romanian, hungarian ones...) depended on a huge number of horses, mules. The biggest number of the wehrmacht divisions could move thanks to the horses, and only few ones were mechanized.
And the russians in 1941 trained dogs to carry on their back a tank grenade with a stick on it. The dogs were trained to find food under the tanks! So, when they saw a german tank, they used to run under it and the bomb exploded. This trick didn' t work well because the german tankers after the first accidents used to shoot any dogs running towards them.
