Cowpox virus and cowpox-like diseases in cattle and buffalo: A comprehensive review

Abstract

Cowpox virus (CPXV) is a zoonotic orthopoxvirus of veterinary and public-health importance because of its broad host range, phylogenomic diversity, and diagnostic complexity. This comprehensive review summarizes current knowledge of CPXV taxonomy, genome organization, host range, transmission ecology, clinical disease, differential diagnosis, laboratory confirmation, molecular epidemiology, and One Health relevance, with particular attention to bovine hosts and the epidemiological context of Iraq and the Middle East. Although historically linked to cattle, current evidence supports a multi-host reservoir–spillover model in which wild rodents are considered the most plausible reservoirs, whereas domestic animals, captive species, livestock, and humans are generally regarded as incidental hosts. In cattle and buffalo, pox-like lesions may resemble those caused by vaccinia-like orthopoxviruses, buffalopox virus, parapoxviruses, lumpy skin disease virus, bovine herpes mammillitis, or non-infectious teat disorders. In water buffalo, published orthopoxvirus literature is dominated by buffalopox rather than confirmed classical CPXV, making etiological confirmation especially important. Clinical and histopathological findings are valuable for recognizing suspected cases but remain insufficient for definitive species-level identification. Molecular approaches, including PCR, sequencing, and whole-genome sequencing, are therefore essential for clarifying viral identity, resolving taxonomic complexity, supporting genomic tracing, and improving molecular epidemiology. In Iraq, published evidence has focused mainly on lumpy skin disease virus and parapoxviruses, while comparable genomic evidence for classical CPXV remains limited, representing an important knowledge gap. Pox-like disease may also impair animal welfare and milk production and create occupational exposure risks for milkers, animal handlers, veterinarians, and laboratory personnel. Overall, integrated field investigation, molecular confirmation, phylogenetic analysis, biosecurity, and One Health surveillance are needed to strengthen detection and interpretation of cowpox-like diseases in Iraq and the wider region.