Equids play a fundamental role in supporting livelihoods in many parts of the world. Being able to access the animal’s welfare, especially while performing tasks that involve high levels of physical effort such as those found in agroforestry activities, is of utmost importance. The Donkey Sanctuary, a UK-based international charitable institution, has designed a project that aims to develop a set of tools to evaluate the working conditions of donkeys and mules worldwide. This requires the measurement of several different parameters, including the force exerted by an animal to pull a load during work. This article presents the stages of design, development and implementation of a device capable of carrying out these measurements with minimal human intervention and with negligible impact on the task operating conditions. Data obtained from real field conditions validates the devised measurement method.