The Chiweenie is a cross between the Chihuahua and Dachshund. Not all of them are guaranteed to live up to their full lifespan. Some have short lifespans due to health problems like dwarfism, allergies, or heart defects. There are also some hereditary disorders that can shorten their lives as well such as epilepsy, hip dysplasia and eye diseases like retinal degeneration syndrome (RDS).