Ivomec Eprinex Pour-On For Beef and Dairy Cattle is formulated for the treatment and control of roundworms, lungworms, grubs, sucking and biting lice, mange mites and horn flies. Ivomec Eprinex Pour-On can be used on lactating dairy cattle and requires no meat withdrawal or milk withholding period. Easy to apply, Ivomec Eprinex Pour-On is weatherproof and is unaffected by extremes in temperature.