Scrapie in Goats: Goat-Specific Aspects of Classical and Atypical Forms—An Updated Review of Pathogenesis, Diagnosis, Genetics, and Control

Scrapie is a fatal neurodegenerative prion disease of sheep and goats, classified among the transmissible spongiform encephalopathies. It occurs in the following two main forms: classical scrapie (CS), which is naturally contagious, and atypical scrapie (AS or Nor98), generally regarded as sporadic with limited natural transmissibility. Goats are susceptible to both forms and present distinct challenges for control, partly because protective PRNP alleles are less frequent than in sheep. This review offers a goat-focused synthesis of prion strain diversity, clinical presentation, pathogenesis, transmission, neuropathology and PrPSc deposition patterns, diagnosis (including emerging techniques and genotype-dependent limitations), and control strategies. Advances from 2021 to 2026 are integrated throughout, with particular attention to caprine PRNP polymorphisms and their effects on susceptibility, diagnostic performance, and resistance breeding. Key polymorphisms at codons 146 (D146 and S146) and 222 (K222) confer substantial resistance to CS strains and remain the cornerstone of control and eradication. Recent EU surveillance shows a continued decline, with 71 goat cases reported in 2024 (65 CS and six AS), all in animals lacking strongly protective alleles. Complete eradication is still difficult because of prion strain diversity, environmental contamination, and uneven implementation of control measures across regions. Persistent gaps include goat prion strain characterization, the long-term durability of resistance alleles against emerging strains, and optimization of genotype-adapted diagnostics. Implications for sustainable disease management in caprine populations are discussed.