A rapid, sensitive, and specific analytical method was developed and validated to quantify acamprosate calcium in beagle dog plasma. The method employs a single plasma protein precipitation, and the analytes are separated by chromatography on an Acquity UPLC HSS T3 column and analyzed by mass spectrometry in the multiple reaction monitoring (MRM) mode. The method has a chromatographic run time of 1.25 min and a linear calibration curve over the range 200-10000 ng/mL ($r^2$ > 0.9994). The intra-day and inter-day accuracy and precision were within 10.0% for the analyte. Acamprosate was stable during all sample storage, preparation, and analytical periods. This method was employed in a pharmacokinetic study of an acamprosate 333 mg enteric-coated tablet in 8 male beagle dogs that received single 666 mg doses (333 mg $ imes$ 2 tablets). The proposed method enables identification and quantification in pharmacokinetic studies of acamprosate in beagle dog plasma.