Cold weather is louse weather. Inadequate nutrition, compromised immune response and shipping stress also favor outbreaks, if there are any infested animals in the herd. Additionally, fewer daylight hours during winter appear to contribute to problems with lice.
Spread and potential problems
Biting and sucking lice have been associated with reduced weight gains and general lack of thriftiness during periods of greatest winter stress. These small external parasites can spread quickly through a herd as animals bunch for warmth or when feeding.