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 anywhere from between 13 to 16 years on average 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.[54] The chemical in the skunk spray is absorbed by the dog and causes the red blood cells to explode, which can occasionally lead to fatal anemia and kidney failure. If sprayed underground, it can also cause chemical burning of the cornea. Treatments are available to flush the toxin out of the dog's system
