Prion diseases, also known as transmissible spongiform encephalopathies (TSEs), are a group of invariably fatal neurodegenerative disorders that affect both animals and humans. In animals, these diseases include scrapie in sheep, chronic wasting disease (CWD) in cervids, bovine spongiform encephalopathy (BSE) in cattle, and transmissible mink encephalopathy (TME) in mink. In humans, prion diseases occur as sporadic, genetic, or acquired conditions, with the sporadic Creutzfeldt–Jakob disease (sCJD) being the most prevalent, accounting for approximately 85% of cases. Among the prion diseases of animals, BSE is particularly significant due to its zoonotic potential. This was demonstrated by its role in the emergence of the variant Creutzfeldt–Jakob disease (vCJD) in humans, highlighting the cross-species transmissibility of prions. This zoonotic risk underscores the need for continued surveillance, rigorous research, and proactive public health measures to mitigate the broader implications of prion diseases for both animal and human populations.