cats that were more likely to experience an earlierdeath, and cats that survived to an older age.

MortalityCats that lived for less than 5 yearsAlmost half of the deaths in cats less than 5 years of age occurred due to trauma, and themajority of these were from road traffic accidents.The two other most common causes of death in this subpopulation of cats were viral infectiousdisorders (6.6%) and respiratory disorders (4.5%).

Increasing our knowledge of the factors that affect the lifespan of cats could enableus to make changes that lead to an improvement in their health and welfare. Withthis in mind, Dan O’Neill, Companion Animal Epidemiologist at VetCompass, along withcolleagues from The Royal Veterinary College, UK, and The University of Sydney,Australia, carried out a study using data collected from the VetCompass database ofveterinary practices in England to find out more about cats’ mortality and longevity.The study was recently published in the ‘Journal of Feline Medicine and Surgery’, theflagship publication of International Cat Care’s veterinary division.

Definitions

Longevity:the length orduration of life

Mortality:the relativefrequency ofdeaths in a

specific population

New Data on the Longevity andMortality of Cats in England

Graph 1: Percentage of cats in the study population that died within 1 year age bands. Photo courtesy of Dan O’Neill

Investigating the mortality and longevity of catscould help us to find out if, or how, differentfactors affect their lifespan.This advance in

understanding could then enable us to makechanges that improve their health and welfare;for example, by improving husbandry procedures,disease prevention strategies, breeding decisionsor clinical care. This study therefore aimed toestimate longevity, report common causes ofmortality and identify demographic risk factorsfor a reduced lifespan in cats in England.

Study dataThe study initially looked at all cats from centraland south-east England with data uploaded ontoVetCompass (see box on page 29 for furtherinformation) between September 2009 andDecember 2012. After taking a random sample andselecting for those with confirmed deaths, 4009cats from 87 practices were included in the study.

LongevityThe study found that the average age of deathwas 14.0 years. The results also showed that, as well as a peak in the number of deaths at 16 years of age, there was an additional peak at 1 year of age (see Graph 1). This led the authorsto propose the existence of two subpopulations:

28 CatCare

Cats that lived for 5 years or longerHalf of all mortalities in cats that lived for 5 years or longer were due to: renal disorder,non-specific illness, neoplastic disorder and mass-associated disorder.The most common of these four causes was

renal disorder, and this accounted for 13.6% ofdeaths. This finding emphasises the importance of carrying out routine health checks, especiallyin older cats, to increase the chances ofdetecting renal disease and optimise itsmanagement. Neoplasia accounted for 12.3% of deaths in

the study. The authors proposed, however, that it was possible that many of the deaths ascribedto non-specific masses (mass-associated disordersthat did not have a more precise cause or originspecified; 11.6%) may have been undiagnosedneoplastic disorders. This suggests that neoplasiacould account for up to a quarter of deaths inolder cats. Although malignant neoplasia oftenshortens the lives of cats, routine veterinaryevaluation in older cats is recommended, asearlier diagnosis may allow for treatments thatcould prolong life or improve palliative care.

Demographic risk factorsPurebred vs crossbredThe study found that crossbred cats lived for an average of 14.0 years, whereas purebred cats lived for an average of 12.5 years. It may be that, due to a smaller gene pool and inbreeding,purebred cats are more likely to succumb torecessive disorders, thus reducing their longevity.However, other genetic and non-genetic factorsare likely to contribute as well.It was also found that the longevity varied

widely between each of the breeds. The Birman,Burmese, Siamese and Persian lived as long as or longer than crossbreds, whereas the Bengal,Abyssinian, Ragdoll, Maine Coon and BritishShorthair breeds showed reduced longevity.

For information about chronic kidney disease please visit

our website www.icatcare.org

VetCompass The Veterinary Companion Animal Surveillance System, or VetCompass, is an ongoing research programme that aims‘to investigate the range and frequency of small animal health problems seen by veterinary surgeons and highlightmajor risk factors for these conditions’. Clinical data from veterinary practices that have signed up to the projectare uploaded on to the VetCompass database. Data includes the animal species, breed, sex and weight, as well asinformation from clinical examination, diagnosis and treatment. Client names, addresses and financial data are not uploaded, keeping the participants anonymous. By July 2014, more than 1.5 million unique animals had been involved in the study. For more information visit: www.rvc.ac.uk/vetcompass.

As a group, purebred cats,including the Maine Coon,were found to live onaverage 1.5 years less than crossbred cats. Photo courtesy of Animal Photography

For information about different cat breeds and inherited disorders in cats, please visit our websitewww.icatcare.org

There are six life stages of the cat. To findout more about

these and health issues encountered atthese stages,visit www.

icatcare.org/advice/life.stage

These differences between the breeds may be due to differing breed bodyweights andpredispositions to specific diseases.Further investigation needs to be carried

out in order to better understand and manage the difference in longevity between purebred and crossbred cats and the variation in longevitybetween different purebred cats.

BodyweightAn increase in bodyweight was found to beassociated with a decrease in longevity. Of thecats that died at 5 years of age or older, thoseweighing less than 3 kg were found to live, onaverage, 1.7 years longer than those weighingbetween 4 and 5 kg. This finding, however, mayhave been affected by the different breeds in the study and the effects of obesity.

Insurance statusAn association was found between insurancestatus and longevity – the longevity of insuredcats was 1.1 years less than non-insured cats.However, this finding was proposed to perhaps be due to fewer older cats being insured because of increasing costs or exclusions.

NeuteringNeutered females and males were found to live,on average, 0.6 and 1.7 years longer than entirefemale and male cats, respectively. There arevarious health benefits to neutering, such asreduced risk of asthma and abscesses, whichwould support this association. However, thisfinding should be interpreted cautiously as theage at neutering was not factored into the analysis.

Reference◆ O’Neill, DG, Church DB, McGreevy PD,

Thomson PC and Brodbelt DC. Longevity and mortality of cats attending primary care veterinary practices in England. J Feline Med and Surg 2015; 17: 125–133.

CatCare 29

Advances in understanding of the mortalityand longevity of cats could enable us tomake changesthat improvetheir health and welfare