MRI is widely used for the detection and characterization of brain lesions. There is a growing interest in the potential benefits of quantitative MRI (qMRI) in veterinary brain lesion diagnosis. Yet, the use of data processing tools in the veterinary field is not as democratized as for the diagnosis of human brain pathologies. Several reviews have addressed the characterization of brain lesions in cats and dogs. None of them is specifically focused on quantitative MRI data processing techniques for the diagnosis of brain lesions in the veterinary field. This paper aims to provide an overview of the evolution of qMRI on cats and dogs both in the clinical and preclinical fields. We analyze the achievements in the field as well as the remaining challenges in the diffusion of data processing tools for veterinary brain lesions characterization.