Lice infestations in cattle peak during winter housing periods and cause significant welfare compromise through pruritus, skin damage, and in severe cases, anemia and production losses.
Lice infestations create persistent, irritating pruritus that disrupts normal behavior across affected cattle. Infested animals spend significant time rubbing and scratching rather than resting, feeding, or engaging in normal social behavior — a measurable welfare cost that accumulates over the winter housing period. Heavy sucking louse burdens in calves can cause anemia severe enough to impair growth and cause clinical signs of blood loss. The winter timing of peak infestations compounds welfare concerns: cattle in winter housing are already subject to space restrictions and altered social dynamics compared to pasture conditions. Treatment at housing before populations build is the most welfare-effective approach, preventing the weeks of pruritic distress that accompany untreated heavy infestations before natural spring decline.