Currently, there are a few or none marketed gabapentin veterinary products, leading to treatment with compounded dosage forms or off-label use of human-marketed products. With the said approaches, there are significant risks of preparation errors, rendering these practices suboptimal. A new manufacturing technique to accurately and rapidly prepare veterinary dosage forms close to the point-of-care is needed. However, a current hurdle in developing small-dose gabapentin dosage forms is the quantification of the gabapentin molecule. UV-Vis spectrophotometric quantification possesses suitable properties for implementation at small production sites, but quantifying gabapentin with the said technique has proven to be challenging as the small molecule lacks chromophores. This study aimed at thoroughly assessing UV-Vis spectrophotometric gabapentin quantification methods with the intent of finding a reliable method. Excellent linearity (R2 = 0.9998) in a broad and useful concentration range (0.5-40 µg/mL) was detected for the ascorbic acid derivatization method at a wavelength of 376 nm. The method was successfully applied to determine the drug content in the prepared semi-solid extrusion 3D-printed dosage forms. This study proved that pet-friendly tailored gabapentin dosage forms could easily be manufactured by semi-solid extrusion 3D printing and UV-Vis spectrophotometrically analyzed with the ascorbic acid derivatization method.