The economic impact of endo- and ectoparasites in dairy cattle.

BACKGROUND: Dairy products provide invaluable sustenance for human populations and any factor that impairs dairy production is a threat to our future food supply. Dairy cattle parasitism is a critical and often unrecognized danger that harms cows; threatens producer livelihoods; can reduce food safety, and hurts farm profitability. Specifically, parasites cause illness and death, reduce milk production, slow weight gain, and harm carcass quality. They may cause abortions, transmit serious bacterial diseases, and harm human health. Cattle movement restrictions to prevent parasite spread add to production costs. Two general parasite types are those found internally (endoparasites) or externally to the animal (ectoparasites) and common parasite classes include: nematodes, trematodes, cestodes, protozoans, arachnids, and insects. CONCLUSIONS: This paper reviews global economic and health impacts of dairy cattle parasitism including discussions of testing methods, treatment strategies, and resistance avoidance.