Moose populations across North America are declining in southern range areas due to tick infestations, brain worm, and habitat changes driven by climate — creating welfare concerns for individual animals.
Heavy winter tick infestations cause visible, prolonged suffering in affected moose. Animals carrying tens of thousands of ticks become anemic, lose body condition, and exhibit frantic rubbing behavior against trees and snow in futile attempts to dislodge parasites. The hair loss resulting from rubbing leaves large bare patches that compromise insulation during winter — increasing cold stress on top of the nutritional and blood loss stress from the infestation itself. Many heavily infested moose die before spring. Brain worm causes progressive neurological deterioration in affected moose — animals show disorientation, fearlessness, and inability to escape before dying. These are individually significant welfare harms affecting large numbers of moose across declining southern populations.