Identifying the adverse impacts of pesticide exposure in rice ecosystems is essential to guide regulations that are protective of wildlife and human health. Amphibians are valuable indicators within rice ecosystems because pesticide applications coincide with sensitive reproductive and developmental life stages. We conducted two experiments using wild cane toads (Rhinella marina) to test whether an environmentally relevant exposure to butachlor, an acetanilide herbicide used extensively in rice, affects amphibian development and whether cane toad tadpoles are capable of acclimatizing to sub-lethal exposure. We found that cane toads exposed to butachlor developed slower and weighed less than controls, and that development of the thyroid gland was affected: exposed individuals had smaller thyroid glands and thyrocyte cells, and more individual follicles. Analyses of the transcriptome revealed that butachlor exposure resulted in downregulation of transcripts related to metabolic processes, anatomic structure development, immune system function, and response to stress. Last, we obsrved evidence of acclimatization, where animals exposed to butachlor early in life performed better than naive animals during a second exposure.