Description of people and animals dying happen throughout. It is also revealed later on in the book that the Martians are feeding off of people's blood.
A few characters are described as becoming mad/losing their minds because of the fear of the martians and they are perceived as weak from the narrator.
A man is mentioned as having his back broken. There is also a brief mention of a man with either a broken or amputated leg, the way it's described is a bit ambiguous.
A few characters are described as "descending into madness" & have raving narrations/erratic behaviors. Physical symptoms (racing heart/etc) are not as described. Due to the plot there is an undercurrent of anxiety throughout the whole book.
Dog fighting is mentioned very briefly, in reference to wild dog packs fighting over food in the deserted areas where the Martians attacked. It's not organized dog fighting or mentioned in great detail.
People attempt to defend themselves against the Martians with major artillery, & individuals are mentioned to have guns used against people trying to rob/loot them in the chaos.