Mastiff breed mortality: A study of owner experience, dog age and longevity.

Despite being ranked 33 in Americas most popular breeds (American Kennel Club, 2020), there is a lack of research addressing longevity and death related health problems of Mastiff dog breeds and specifically commonly kept Bull Mastiffs and English Mastiffs. Likely a result of small founder populations and minimal breeding geographical locations, limited genetic variation is found making it important to determine key health concerns which may reduce longevity. The purpose of this study was to report findings from an online global survey of owners of deceased Mastiffs detailing breed, age at death, and if known, cause of death. Owner information was also collected including location by continent and country and the owners breeding or hobbyist experience. A closed-question survey was used via an online network of global Mastiff clubs and associations totalling a useable sample of 1036 dogs across a range of breeds. Notably, it is reported that age and cause of death varied dependant on breed. Results indicate that the median age of death for all dogs was 8 years with mean age of death in Europe as 7.72 years and 8.17 years in North America. The most common cause of death identified for all dogs was cancer (47%), old age (16%), cardiac problems (8%) and gastric problems including GDV and bloat (7%). The mean age of death for cancer dogs was 7.85 years with 23 types of cancer stated with Osteosarcoma being the most commonly recorded and specifically for neutered animals. As the survey was aimed at hobbyist and registered breeders, study findings contribute to knowledge of Mastiff mortality with the aim of promoting welfare of the breed.