New Data on the Longevity and Mortality of Cats in England

New Data on the Longevity and
Mortality of Cats in England
I
Increasing our knowledge of the factors that affect the lifespan of cats could enable
us to make changes that lead to an improvement in their health and welfare. With
this in mind, Dan O’Neill, Companion Animal Epidemiologist at VetCompass, along with
colleagues from The Royal Veterinary College, UK, and The University of Sydney,
Australia, carried out a study using data collected from the VetCompass database of
veterinary 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’, the
flagship publication of International Cat Care’s veterinary division.
nvestigating the mortality and longevity of cats
could help us to find out if, or how, different
factors affect their lifespan.This advance in
understanding could then enable us to make
changes that improve their health and welfare;
for example, by improving husbandry procedures,
disease prevention strategies, breeding decisions
or clinical care. This study therefore aimed to
estimate longevity, report common causes of
mortality and identify demographic risk factors
for a reduced lifespan in cats in England.
Study data
The study initially looked at all cats from central
and south-east England with data uploaded onto
VetCompass (see box on page 29 for further
information) between September 2009 and
December 2012. After taking a random sample and
selecting for those with confirmed deaths, 4009
cats from 87 practices were included in the study.
Longevity
The study found that the average age of death
was 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 authors
to propose the existence of two subpopulations:
28 CatCare
Definitions
Longevity:
the length or
duration of life
Mortality:
the relative
frequency of
deaths in a
specific population
Graph 1: Percentage of cats in the study population
that died within 1 year age bands. Photo courtesy of
Dan O’Neill
cats that were more likely to experience an earlier
death, and cats that survived to an older age.
Mortality
Cats that lived for less than 5 years
Almost half of the deaths in cats less than
5 years of age occurred due to trauma, and the
majority of these were from road traffic accidents.
The two other most common causes of death
in this subpopulation of cats were viral infectious
disorders (6.6%) and respiratory disorders (4.5%).
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 highlight
major risk factors for these conditions’. Clinical data from veterinary practices that have signed up to the project
are uploaded on to the VetCompass database. Data includes the animal species, breed, sex and weight, as well as
information 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.
Cats that lived for 5 years or longer
Half 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% of
deaths. This finding emphasises the importance
of carrying out routine health checks, especially
in older cats, to increase the chances of
detecting renal disease and optimise its
management.
Neoplasia accounted for 12.3% of deaths in
the study. The authors proposed, however, that
it was possible that many of the deaths ascribed
to non-specific masses (mass-associated disorders
that did not have a more precise cause or origin
specified; 11.6%) may have been undiagnosed
neoplastic disorders. This suggests that neoplasia
could account for up to a quarter of deaths in
older cats. Although malignant neoplasia often
shortens the lives of cats, routine veterinary
evaluation in older cats is recommended, as
earlier diagnosis may allow for treatments that
could prolong life or improve palliative care.
Advances in
understanding
of the mortality
and longevity
of cats could
enable us to
make changes
that improve
their health
and welfare
Purebred vs crossbred
The 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 to
recessive disorders, thus reducing their longevity.
However, other genetic and non-genetic factors
are 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 British
Shorthair breeds showed reduced longevity.
There are six
life stages of
the cat. To find
out more about
these and
health issues
encountered at
these stages,
visit www.
icatcare.org/
advice/life.stage
Demographic risk factors
For information about chronic
kidney disease please visit
our website www.icatcare.org
These differences between the breeds may
be due to differing breed bodyweights and
predispositions 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 longevity
between different purebred cats.
Bodyweight
An increase in bodyweight was found to be
associated with a decrease in longevity. Of the
cats that died at 5 years of age or older, those
weighing less than 3 kg were found to live, on
average, 1.7 years longer than those weighing
between 4 and 5 kg. This finding, however, may
have been affected by the different breeds in
the study and the effects of obesity.
Insurance status
An association was found between insurance
status and longevity – the longevity of insured
cats 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.
Neutering
Neutered females and males were found to live,
on average, 0.6 and 1.7 years longer than entire
female and male cats, respectively. There are
various health benefits to neutering, such as
reduced risk of asthma and abscesses, which
would support this association. However, this
finding should be interpreted cautiously as the
age 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.
As a group, purebred cats,
including the Maine Coon,
were found to live on
average 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 website
www.icatcare.org
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