The Jack Russell Terrier is a small terrier that has its origins in fox hunting in England. It is principally white-bodied and smooth, rough or broken-coated and can be any colour. The breed has a reputation for being healthy with a long lifespan. Breeders have protected the gene pool, and direct in-line breeding has been prevented. Jack Russells can live from 13 to 16 years given proper care. However, certain lines have been noted for having specific health concerns and, therefore, could occur in any line or generation because of recessive genes. These issues can include hereditary cataracts, ectopia lentis, congenital deafness, patellar luxation, ataxia, myasthenia gravis, Legg–Calvé–Perthes syndrome, and von Willebrand disease.