The average lifespan of a Jack Russell terrier is between 12 and 16 years. However, some Jack Russells have been known to live to 20 years or more.
So, if you are looking for a dog that will be a lifelong companion, a Jack Russell may be a good choice. This is an upbeat and lively dog breed that is intelligent with an escape tendency, so gardens and backyards need to be properly secured. Jack Russells are good at digging beneath fences to escape.