Ectoparasiticide-containing collars for pets

An ectoparasiticide-containing polyurethane collar for animals, which comprises a hydrophobic polyurethane which cannot be swollen in water and which contains, relative to the polyurethane, 2 to 30% by weight of an ectoparasiticide, said ectoparasiticide selected from the group consisting of an insecticidally active carbamate having a vapor pressure of between about 10.sup.-4 and 10.sup.-6 mm Hg measured at 20.degree. C., and an insecticidally active synthetic pyrethroid, and combinations thereof and, relative to the polyurethane, 8 to 25% by weight of a spreading agent, said speading agent selected from the group consisting of silicone oils, fatty acid esters, fatty alcohols, fatty acids and combinations thereof.