Selective breeding has introduced heritable conditions into some livestock breeds that cause significant welfare problems, requiring screening, eradication programmes, and industry reform.
Genetic disease in livestock represents a welfare harm that has been inadvertently introduced through selective breeding for production traits. Conditions including spider lamb syndrome, double muscling in cattle, and inherited metabolic disorders can cause severe and chronic suffering in affected animals. Modern DNA-based genetic testing allows rapid identification of carriers, making eradication programmes achievable where there is industry will. The welfare case for mandatory genetic screening requirements in pedigree breed registration is strong: preventing the birth of animals with heritable painful conditions is more effective than attempting to treat them. Breed associations and registration bodies have an important role in implementing and enforcing screening requirements.