title: Ruminant self-medication against gastrointestinal nematodes: evidence, mechanism, and origins.
abstract: Gastrointestinal helminths challenge ruminants in ways that reduce their fitness. In turn, ruminants have evolved physiological and behavioral adaptations that counteract this challenge. Ruminants display anorexia and avoidance behaviors, which tend to reduce the incidence of parasitism. In addition, ruminants appear to learn to self-medicate against gastrointestinal parasites by increasing consumption of plant secondary compounds with antiparasitic actions. This selective feeding improves health and fitness. Here, we review the evidence for self-medication in ruminants, propose a hypothesis to explain self-medicative behaviors (based on post-ingestive consequences), and discuss mechanisms (e.g., enhanced neophilia, social transmission) that may underlie the ontogeny and spread of self-medicative behaviors in social groups. A better understanding of the mechanisms that underlie and trigger self-medication in parasitized animals will help scientists devise innovative and more sustainable management strategies for improving ruminant health and well-being.
authors: Department of Wildland Resources, Utah State University, 5230 Old Main Hill, Logan, Utah 84322-5230, USA.
authors: Juan J
authors: JJ
authors: Villalba
authors: Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, 70803 Baton Rouge, USA.
authors: James
authors: J
authors: Miller
authors: Department of Natural Resources, Institute of Plant Sciences, Agricultural Research Organization, the Volcani Center, Bet Dagan 50250, Israel.
authors: Eugene D
authors: ED
authors: Ungar
authors: Department of Natural Resources, Institute of Plant Sciences, Agricultural Research Organization, the Volcani Center, Bet Dagan 50250, Israel.
authors: Serge Y
authors: SY
authors: Landau
authors: Department of Biology, Barnard College, Columbia University, 3009 Broadway, New York, NY, USA.
authors: John
authors: J
authors: Glendinning
mesh_terms: D000220:Adaptation, Biological; D000818:Animals; D000855:Anorexia / Q000209:etiology / Q000662:veterinary; D000871:Anthelmintics / Q000032:analysis; D004435:Eating; D005247:Feeding Behavior; D005518:Food Preferences; D015511:Goat Diseases / Q000188:drug therapy* / Q000469:parasitology / Q000517:prevention & control; D006041:Goats / Q000469:parasitology / Q000523:psychology; D006373:Helminthiasis / Q000188:drug therapy / Q000469:parasitology / Q000517:prevention & control; D006790:Host-Parasite Interactions; D007410:Intestinal Diseases / Q000188:drug therapy / Q000469:parasitology / Q000517:prevention & control / Q000662:veterinary*; D007411:Intestinal Diseases, Parasitic; D007858:Learning; D008425:Maternal Behavior; D008954:Models, Biological; D009348:Nematoda / Q000502:physiology; D009349:Nematode Infections / Q000188:drug therapy / Q000517:prevention & control / Q000662:veterinary*; D008517:Phytotherapy / Q000662:veterinary*; D010946:Plants, Medicinal / Q000737:chemistry; D012651:Self Medication / Q000662:veterinary*; D012756:Sheep / Q000469:parasitology / Q000523:psychology; D012757:Sheep Diseases / Q000188:drug therapy* / Q000469:parasitology / Q000517:prevention & control; D013634:Tannins / Q000032:analysis; D013649:Taste
chemical_list: D000871:Anthelmintics; D013634:Tannins