In a peer-reviewed scientific article published on June 25, 2014 in the journal Environmental Health, leading endocrine disrupting chemicals (EDCs) scientists illuminate disadvantages of using gavage for oral dosing in animal experiments (Vandenberg et al. 2014). The authors led by Laura Vandenberg of University of Massachusetts conclude that gavage “does not appropriately model human dietary exposures for many chemicals”.
Oral gavage is a dosing method commonly used in toxicological animal testing, where a tube or metal hose is put down an animal’s throat, thus delivering an exact dose of the test chemical directly into the animal’s stomach. Gavage offers the advantage of exact, controlled dosing, however it also bypasses potential chemical absorption through the mouth’s mucosa—a phenomenon recently shown to be of relevance for the chemical bisphenol A (BPA, FPF reported). Gavage may also result in a stress response in test animals. This may mask differences between exposed and control animals, making it less likely to detect statistically significant effects of EDCs.
In the past, risk assessors have focused mainly on studies using oral gavage experiments, because they were deemed exposure routes relevant for humans, while excluding studies using dosing methods like interperitoneal injection (where a chemical substance is injected directly into an animal’s body cavity) or implanted pumps. In their present article, Vandenberg and colleagues question this practice and state that “gavage is not appropriate for the assessment of EDCs”.
University of Massachusetts (June 25, 2014). “Animal testing methods for endocrine disruptors should change, says UMass Amherst health scientist.”
FPF article (June 13, 2013) “New study shows impact of oral dosing on free BPA levels.“
Vandenberg, L. et al. (2014). “Should oral gavage be abandoned in toxicity testing of endocrine disruptors?” Environmental Health, 13:46.