what's the lifespan of a jack russell terrier
Thirteen to sixteen years
Jack Russell Terrier
13 to 16 years 
wiki:19561856
Jack Russell Terrier [SEP] Health
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. Being a hunt-driven dog, the Jack Russell will usually pursue most creatures that it encounters. This includes the skunk, and the breed is prone to skunk toxic shock syndrome.