The association between infrared thermal imagery of core eye temperature, personality, age and housing in cats

https://doi.org/10.1016/j.applanim.2017.01.004Get rights and content

Highlights

  • This study assessed how stress is associated with personality, age and housing in cats.

  • Personality measured by validated objective questionnaire predicted stress responses.

  • Older and singly housed cats showed higher stress responses in cattery environments.

  • These findings may help target enrichment towards vulnerable individuals.

  • This may improve adoption rates and success by stimulating desirable behaviour.

Abstract

Understanding individual responses to stress is a key aspect of maintaining optimal animal welfare. This is especially important where animals are being kept in sub-optimal environments or where the species may not clearly demonstrate stress. Therefore, the aim of this study was to investigate how stress varies in cats in a cattery environment in association with personality, age and housing. Stress was measured using Infrared Thermal Imaging (IRT) of core eye temperature and compared with scores from the Feline Temperament Profile (FTP), age and single or group housing (n = 34). It was predicted that higher eye temperature would be inversely correlated with acceptable scores and directly correlated with questionable scores calculated from the FTP as these are suggested to indicate a stress sensitive cat. As predicted, eye temperature correlated significantly with acceptable FTP scores (rs = −0.377, p = 0.028). Eye temperature was also higher in older cats (rs = 0.417, p = 0.014) and those singly-housed compared with group housed (U = 37, N1 = 12, N2 = 22, P = 0.001). This provides preliminary evidence that personality may predict stress sensitivity in cats and that older and singly housed cats may find the cattery environment more aversive. These findings may improve adoption rates as unresolved stress can cause avoidance and aggressive behaviour, both of which are undesirable in companion animals. Further, they may increase adoption success rates if owners have more knowledge of the personality and likely stress sensitivity of the cat before adopting. In addition, educating owners that the cat they have adopted is stress sensitive will encourage greater vigilance and awareness of subtle indicators of stress, thus improving welfare.

Introduction

Understanding stress is key to enable effective management and improvement of the welfare of animals in our care. There are many potential challenges that cause stress such as artificial lighting, loud noises, arousing odours, uncomfortable temperatures, confined spaces, restricted movement, and forced proximity to humans and other animals (Morgan and Tromborg, 2007a, Morgan and Tromborg, 2007b). However, an individual’s response to such stressors can also be affected by individual differences such as personality, and how well the individual copes within its environment (Biro and Stamps, 2008, Koski, 2011). Personality can have implications on the behaviour and coping ability of an animal (Ijichi et al., 2013a, Ijichi et al., 2013b) and tolerance to pain (Ijichi et al., 2014). It has also been shown that different personality coping styles correlate with different physiological responses as well as health implications such as immunodeficiency (Koolhaas, 2008, Koolhaas et al., 1999). Therefore, it is crucial that methods of welfare assessment take accurate indicators of the welfare state of the individual whilst taking into consideration individual personality.

The welfare of domestic cats is an area of concern for several reasons. First, estimates of numbers of household cats suggest 26% of households have a cat accounting for approximately 10,332,955 individuals in the UK (Murray et al., 2010) without considering feral populations. Therefore, if welfare is not measured accurately in this species, there is the potential for a large number of individuals to suffer. Second, it is suggested that accurate stress assessment in cats is difficult using behavioural indicators (Morgan and Tromborg, 2007a, Morgan and Tromborg, 2007b, Ottway and Hawkins, 2003). Many cats will display hiding behaviours instead of vocalisations when confronted with a stressful situation (Nibblett et al., 2015). Finally, there are a large number of shelter centres which function to re-home and house unwanted animals. This environment may cause stress, especially for feral or older individuals who may be less flexible in response to this environmental change. Stress is associated with avoidance and aggressive behaviour (Amat et al., 2015, Siegford et al., 2003) which are considered undesirable to potential new owners. This may impact on adoption rates if this behaviour is not resolved. This may result in long term housing of unwanted animals and potentially euthanisation. Therefore, accurate identification of stress sensitive individuals that may not cope adequately with sub-optimal environments is crucial for the welfare of a large number of individuals. Feline personality assessment may play an important role in this.

The Feline Temperament Profile (FTP) is a non-invasive objective questionnaire based approach to categorise the temperament of cats based on how they react to human actions (Lee et al., 1983). The FTP has been validated as a measure of temperament in regards to responses to human presence and it has been proposed to relate to stress sensitivity by Siegford et al. (2003). In addition, this study indicated that the test is stable across time and, importantly, before and after adoption has taken place. However, previous studies were not able to validate this method against salivary cortisol levels (Iki et al., 2011, Siegford et al., 2003). This may be because accurate measurements of cortisol are notably difficult as levels may be rapidly metabolized (Schatz and Palme, 2001). Therefore, the current study will compare FTP scores with Infrared thermography.

Infrared thermography is an alternative non-invasive stress assessment method (Stewart et al., 2005). Stress causes an increase in core body temperature (Bouwknecht et al., 2007, Ogata et al., 2006, Oka et al., 2001) and eye temperature reliably correlates with the core body temperature taken from the rectum (Cook et al., 2001, Johnson et al., 2011, Ogata et al., 2006). Travain et al. (2015) measured dog eye and rectal temperature before, during and after a veterinarian visit. Both measurements were consistently similar when the core body temperature rose during the clinical examination, indicating a stress response (Bouwknecht et al., 2007). Several studies have also specifically assessed an area of the eye called the lacrimal caruncle which is the hottest point of the eye and most representative of the core body temperature (Stewart et al., 2008, Stewart et al., 2005, Valera et al., 2012).

The current study aims to assess the FTP as a method of predicting stress sensitivity in cats as measured by thermal imagery. To do this, core eye temperature, as measured from the lacrimal caruncle, was compared against acceptable and questionable scores from the FTP in an applied cattery setting. It is hypothesised that individuals scoring low on acceptable and high on questionable traits will have higher eye temperatures as both are expected to indicate stress levels. As a secondary aim, the welfare states of cats housed singly or in groups will be explored as well as variation across ages. This was to determine the possible impact of these facts on tolerance to a cattery environment.

Section snippets

Animals and housing

The research was carried out at three separate cat rehoming centres on thirty-four cats using opportunistic sampling (Table 1). The centres were located in Newbury, West Berkshire, England (n = 12); Newent, Gloucestershire, England (n = 18); and Great Shefford, West Berkshire, England (n = 4). All cats were neutered, mixed breed (domestic short and long haired) and ranged in age from six months to fifteen years old (mean = 6.10 ± 4.69). All cats studied has been in the centres at least two days to allow

Results

Spearman’s rank correlation showed a significant negative correlation existed between acceptable and questionable FTP scores (rs = −0.825, N = 34, p < 0.000). Spearman’s rank correlation showed a significant negative correlation between eye temperature and acceptable FTP scores (rs = −0.377, N = 34, p = 0.028; Fig. 1). There was no significant correlation between eye temperature and questionable scores (rs = 0.324, N = 34, p = 0.061; Fig. 2).

Spearman’s rank correlation revealed a significant positive correlation

Discussion

The current study aimed to assess the Feline Temperament Profile as a predictor of stress sensitivity in cats. Eye temperature readings were compared to a validated Feline Temperament Profile (FTP) which had previously been shown to accurately predict behavioural indicators of temperament in cats (Lee et al., 1983, Siegford et al., 2003). Using eye temperature readings, results suggest that this FTP may be a valid predictor of stress sensitivity in cats. In addition, it was noted that stress

Conclusion

The current study compared a validated feline temperament profile with thermal imagery to assess stress levels of cats in a rehoming centre. Eye temperature was higher in cats with low acceptable FTP scores, suggesting that these personality types might be more sensitive to stress. This study provides preliminary data indicating that the Feline Temperament Profile is a valid, non-invasive and cost effective means of predicting stress sensitivity in cats in real-world scenarios. FTP would be a

Authorship

The idea for the paper was conceived by CI; The study was designed by CI & SF; Data was collected by SF; Data was analysed by SF & CI; The paper was written by SF & CI.

Conflict of interest

The authors of this manuscript have no conflict of interest to declare.

Acknowledgments

We would like to thank the animal centres Newbury Cats Protection, New Start Cat Rescue Gloucester and National Animal Welfare Trust Berkshire for providing the subjects for this study.

References (38)

  • J.M. Koolhaas

    Coping style and immunity in animals: making sense of individual variation

    Personal. Dis.

    (2008)
  • K. Morgan et al.

    Sources of stress in captivity

    Appl. Anim. Behav. Sci.

    (2007)
  • K.N. Morgan et al.

    Sources of stress in captivity

    Appl. Anim. Behav. Sci.

    (2007)
  • B.M. Nibblett et al.

    Comparison of stress exhibited by cats examined in a clinic versus a home setting

    Appl. Anim. Behav. Sci.

    (2015)
  • N. Ogata et al.

    Objective measurement of fear-associated learning in dogs

    J. Vet. Behav. Clin. Appl. Res.

    (2006)
  • M. Stewart et al.

    Eye temperature and heart rate variability of calves disbudded with or without local anaesthetic

    Physiol. Behav.

    (2008)
  • T. Travain et al.

    Hot dogs: thermography in the assessment of stress in dogs (Canis familiaris)—a pilot study

    J. Vet. Behav. Clin. Appl. Res.

    (2015)
  • M. Valera et al.

    Changes in eye temperature and stress assessment in horses during show jumping competitions

    J. Equine Vet. Sci.

    (2012)
  • M. Amat et al.

    Stress in owned cats: behavioural changes and welfare implications

    J. Feline Med. Surg.

    (2015)
  • Cited by (27)

    • Scaredy-cat: Assessment of individual differences in response to an acute everyday stressor across development in the domestic cat

      2022, Applied Animal Behaviour Science
      Citation Excerpt :

      It has been previously reported that exposure to a stressful situation is accompanied by changes in core body temperature in domestic kittens, although this change could be positive or negative (Marchei et al., 2009) and its repeatabilty is unkown. The temperature of the medial canthus of the eye is reportedly correlated with core body temperature during rest and activity (Zanghi, 2016), and in domestic cats the average eye temperature has also been correlated with scores on the Feline Temperament Profile questionnaire, which categorises individuals based on their reactions towards humans (Foster and Ijichi, 2017). However, our results indicate that changes in eye temperature in response to an acute stressor are not repeatable in domestic cats, and therefore this region may not be adequate for the assessment of acute stress in this species.

    • Fearfulness associates with problematic behaviors and poor socialization in cats

      2022, iScience
      Citation Excerpt :

      Previous literature has found occasionally contradictory breed differences between these behaviors (Naderi et al., 2011; Hart and Hart, 2013; Tamimi et al., 2015; Wassink-van der Schot et al., 2016; Ahola et al., 2017; Salonen et al., 2019; Mikkola et al., 2021). Certain personality types are also suggested to be more prone to stress (Foster and Ijichi, 2017) and, thus, to more readily develop problematic behaviors than others. The co-occurrence of multiple problematic behaviors is likely, as e.g. fear-related aggression is quite common in cats (Amat and Manteca, 2019).

    • Increasing shelter cat welfare through enrichment: A review

      2022, Applied Animal Behaviour Science
      Citation Excerpt :

      Some studies have found beneficial outcomes for cats placed in group housing. For example, cats who are housed alone, compared to those housed with conspecifics, can be more stressed (Foster and Ijichi, 2017; Tanaka et al., 2017). One study examined the opportunity for shelter cats to receive social enrichment through group housing.

    View all citing articles on Scopus
    View full text