Spotlight on Science: Prevalence of Disease and Age-Related Behavioural Changes in Cats: Past and Present

This article first appeared on iCatCare:

Nathalie Dowgray, iCatCare’s Head of ISFM, discusses Dr Sordo and colleagues’ recent paper on the prevalence of disease and age-related behavioural changes in cats: past and present. We couldn’t think of a better person to delve into this paper than Nathalie as she is in the final stages of her PhD on healthy feline ageing!

Nat says…

…ageing and the development of age-related diseases in cats can lead to changes in a cat’s behaviour.

For the cat owner and the veterinary surgeon, it can be difficult to determine what is normal ageing and what are early clinical signs of diseases that require further investigation.  This paper by veterinary researchers Lorena Sordo, Professor Daniella Gunn-Moore from the Royal (Dick) School of Veterinary Studies, University of Edinburgh, UK and their colleagues, including iCatCare’s very own Vicky Halls, brings together two sets of data collected from questionnaires completed by owners of cats aged 11 years or older. Cats in this age category are considered seniors  (Click for more information about cat life stages). The biological ageing process begins from 7 years of age in cats and the risk of age related disease increases from around 9-10 years of age (Bellows et al., 2016). Thus, the populations of cats selected in this paper are ones where age-related changes to health and behaviour should be present.

The two data sets were collected from different time points (one in 1995 and the other from 2010-2015) and used slightly different methodologies and questionnaires. This did mean that direct comparisons could not always be made between the two populations, but it was interesting to be able to compare owner awareness of disease over 15-20 years as there have been significant improvements in veterinary medicine during this time.

The most common owner observed changes with age were increased vocalisation, increased sociability and increased house soiling. Appetite, grooming and willingness to go outside all decreased with age.

There was greater owner awareness of diseases in the later survey data (2010-2015). This may not indicate that this was a ‘sicker’ population of cats but that veterinary medicine had improved in the 15-20 years between the two surveys and cats with many of these conditions were being diagnosed and treated earlier in the disease process. It has been shown that cats were living longer in 2006 compared to 1999 reflecting an improvement in veterinary care over a similar timespan (Egenvall et al., 2009). In addition, it could reflect positive changes in the cat-owner relationship that led to a better understanding of feline behaviour and owners recognising when their cat is not quite right. In the Sordo et al. paper, older cats were more likely to have been diagnosed with kidney disease, blindness, hyperthyroidism, arthritis, heart disease, deafness and dental disease. Only lower urinary tract infections and diabetes did not have an association with age.

This study found numerous associations between the presence of disease states and owner observed behavioural changes, however, for these comparisons they did not take into consideration the influence of age. Where diseases and owner reported behavioural changes both showed an association with increased age, it is difficult to determine if age or disease is the driver of the behaviour change. In addition, many of these disease conditions exist on a spectrum, the severity of clinical symptoms of disease and how these may impact on owner observed behaviour will vary with how advanced the disease state is. Comorbidities (more than one disease being present at the same time) are very common in ageing cats and the presence of a number of conditions would not be unexpected. This will also confound the owner observed changes as it would be difficult to know which disease is to ‘blame’ for the behavioural change. There was also no mention of hypertension (high blood pressure) in the disease categories, 24.5% of the cats in the second later survey were reported to have had their blood pressure measured at the vets and 10.4% of the cats in this cohort were reported to be blind. Damage to the back of the eye caused by high blood pressure (hypertensive retinopathy) is a common cause of blindness in older cats (Carter et al., 2014; Sansom et al., 2004) but there were no details as to the cause of blindness in these cats. There is an assumption that at least some of them may be living with hypertension and blindness concurrently. Hypertension is also a common secondary condition associated with kidney disease and hyperthyroidism and it would be expected that the number of the cats reported with these conditions may also have hypertension which could be contributing to the owner observed behavioural changes. High blood pressure in cats is associated with hypertensive encephalopathy (damage to to brain)  which can lead to depression and lethargy (Taylor et al., 2017). In people this condition is associated with headaches, nausea and confusion, we have to assume that it causes similar feelings in cats which leads to the depression and lethargy.

Despite these concerns about the results regarding associations between owner observed behaviour and disease, this paper does raise a very good point. Changes to cats behaviour with increasing age is very common and these changes should not be dismissed as ‘normal’ ageing. Veterinary surgeons should be regularly including questions around behavioural changes in ageing cats when they take a clinical history and owners should be aware of the importance of mentioning any changes that they have observed in their cats behaviour as they have aged, as it may prompt their vet to investigate things further.

Key behavioural changes to watch out for

  • Vocalisation changes (day and night)
  • Sociability with people and other pets
  • Agitation or irritation for no apparent reason
  • Changes in appetite
  • Changes in weight
  • Changes in water intake
  • Grooming
  • Changes in play and hunting
  • Changes in sleeping patterns
  • Willingness to go outside
  • House soiling.

At International Cat Care we have developed the Cat Care for Life programme which helps cat owners and vets to work together to keep cats happy and healthy through all of their life stages. This programme includes recommendations to maximise the early detection of age related disease before they start having a significant impact on your cat’s welfare and behaviour. For more information see

Reference for the study

Sordo, L., Breheny, C., Halls, V., Cotter, A., Tørnqvist-Johnsen, C., Caney, S., & Gunn-Moore, D. (2020). Prevalence of Disease and Age-Related Behavioural Changes in Cats: Past and Present. Veterinary Sciences7(3), 85.

Additional References

Bellows, J., Center, S., Daristotle, L., Estrada, A. H., Flickinger, E. A., Horwitz, D. F., Lascelles,

  1. D. X., Lepine, A., Perea, S., Scherk, M., & Shoveller, A. K. (2016). Evaluating aging in cats: How to determine what is healthy and what is disease. Journal of Feline Medicine and Surgery, 18(7), 551–570.

Carter, J. M., Irving, A. C., Bridges, J. P., & Jones, B. R. (2014). The prevalence of ocular lesions associated with hypertension in a population of geriatric cats in Auckland, New Zealand. New Zealand Veterinary Journal, 62(February 2015), 21–29.

Egenvall, A., Nodtvedt, A., Haggstrom, B., Ström Holst, B., Moller, L., & Bonnett, B. (2009). Mortality in Life-Insured Sedish Cats during 1999-2006: Age, Breed, Sex and Diagnosis. Journal of Veterinary Internal Medicine, 23, 1175–1183.

Sansom, J., Rogers, K., & Wood, J. L. N. (2004). Blood pressure assessment in healthy cats and cats with hypertensive retinopathy. American Journal of Veterinary Research, 65(2), 245–252.

Taylor, S. S., Sparkes, A. H., Briscoe, K., Carter, J., Sala, S. C., Jepson, R. E., Reynolds, B. S., & Scansen, B. A. (2017). ISFM Consensus Guidelines on the Diagnosis and Management of Hypertension in Cats. Journal of Feline Medicine and Surgery, 19(3), 288–303.

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2 thoughts on “Spotlight on Science: Prevalence of Disease and Age-Related Behavioural Changes in Cats: Past and Present

  1. Christine Carroll says:

    Thank you for this information my boy is nearly 14 and I notice slight changes as being more vocalized and he also has arthritis in his back legs. The thing is we’re growing old together. I love him so much.x???

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