It's been known for decades that animals such as chimpanzees seek out medicinal herbs to treat their diseases. But in recent years, the list of animal pharmacists has grown much longer, and it now appears that the practice of animal self-medication is a lot more widespread than previously thought, according to Professor Mark Hunter and his colleagues.
Animals use medications to treat various ailments through both learned and innate behaviors. The fact that moths, ants and fruit flies are now known to self-medicate has profound implications for the ecology and evolution of animal hosts and their parasites, according to Hunter.
In addition, because plants remain the most promising source of future pharmaceuticals, studies of animal medication may lead the way in discovering new drugs to relieve human suffering, Hunter and two colleagues wrote in a review article titled "Self-Medication in Animals," published online April 11 in the journal Science. Beyond self-medication, there are many cases in which animals medicate their offspring or other kin.
The authors argue that animal medication has several major consequences on the ecology and evolution of host-parasite interactions. For one, when animal medication reduces the health of parasites, there should be observable effects on parasite transmission or virulence.
The authors also note that the study of animal medication will have direct relevance for human food production. Disease problems in agricultural organisms can worsen when humans interfere with the ability of animals to medicate, they point out.
The first author of the Science paper is Jacobus de Roode, assistant professor of biology, Emory University. The other author is Thierry Lefevre of the Institut de Recherche pour le Developpement in France.
Caption: A parasite-infected monarch butterfly lays her eggs on medicinal tropical milkweed that will help to protect her offspring from disease. Credit: Jaap de Roode
U-M News Service press release