Drug resistance is complicating the treatment of parasitic diseases. Parasites resort to multiple biochemical means to achieve resistance. Understanding drug resistance is essential for the control of parasitic diseases.
Understanding antiparasitic resistance is important when considering your parasite control options. Antiparasitic resistance is the genetic ability of parasites to survive the effects of an antiparasitic drug that was previously effective, and it continues to grow.
“We have little knowledge about the true extent of the problem,” says Ray Kaplan, DVM, PhD, University of Georgia College of Veterinary Medicine. “However, based on my own experience testing operations and discussing with colleagues around the country, resistance in some species of parasites is a real problem and quite widespread.”
Several factors contribute to antiparasitic resistance:
Parasite biology and genetics
Immune status of the host
Drug mode of action and efficacy
Dose and frequency of treatments
Managing “refugia” is a relatively new approach to tackling the issue, Kaplan says, and many producers may not understand it or be aware of its benefits. Refugia is the concept of leaving some internal parasites unexposed to a dewormer, essentially giving them refuge, and thereby reducing the drug-resistance selection pressure caused by the dewormer. It can help slow down the development of resistance.