Introduction

The first presentation in this series reviewed the impact of patients' stress on the animals themselves and on the veterinary business. The second presentation outlined some simple, evidence-based approaches to patient care that may not be well known, but that can help to reduce patients' fear and anxiety while at the clinic or at home. The present talk reviews some behavioural signs of stress, commonly encountered in veterinary practice, in cats, dogs and rodents. Video footage includes the different manifestations of stress in caged cats, and conflict behaviours in dogs.

Veterinary medicine has traditionally concerned itself with animals' physical fitness, and veterinarians are justifiably proud of their work in this regard. However, for most owners, their animals' feelings are also of great concern, not least when the animals are hospitalised. Meanwhile, in the busyness of the clinical day, it is understandably all too easy to overlook patients' feelings during the handling and procedures involved in delivering a high standard of veterinary healthcare. For example, it has traditionally been quite common to regard patients with cautious resignation (e.g., patients whose records are marked 'Nasty', 'Beware' or 'Bites'), with ignorance (e.g., telling owners whose dogs struggle wildly when restrained that the dogs are acting like naughty toddlers and need to know who's in charge) or with misplaced moral judgment, as when a terrified animal remains completely still while undergoing a procedure such as venipuncture, and the owner is told how 'good' the animal has been.

Meanwhile, recent research indicates that some dogs and cats experience extreme stress through being separated from their owners and kept in a cage (Dybdall, et al., 2007; Välsänen, et al., 2005). That is, the animals undergo physiological changes such as increased heart rate and cortisol release that are associated with negative feelings such as anxiety or fear (Gregory, 2004, pp 12-17), which may make them very difficult to handle. While short-term stress is not necessarily harmful physically, it creates a powerful learning experience for animals such that future visits to the clinic may be just as, or ever more, distressing. Moreover, the animals' resultant behaviours can put them and the surrounding personnel at risk.

Signs of Stress

If our collective professional assumption is that we are the experts in animal welfare, it follows that we must pay as much attention to the mental wellbeing of our patients as we do to their physical wellbeing, especially when they are in our clinic. What are the signs of stress in our patients?

Cats

Cats that are stressed by caging typically manifest this in one of three ways: by hiding in the litter tray or under the bedding (fear), by restlessness and vocalisation (frustration), or by immobility and self-neglect (depression) (BCSPCA, 2004). The degree of stress can be quantified by use of the Kessler Turner Cat Stress Score (Kessler and Turner, 1997) with which the observer rates each of 11 different aspects of posture, activity and vocalisation, on a scale of 1 (fully relaxed) to 7 (terrorised).

Dogs

Stress behaviours in dogs at the veterinary clinic or hospital may include any of: panting, yawning, licking the lips, auto-grooming, paw-lifting, being at the front of the kennel, restlessness, vocalisation (whining, howling, barking), a lowered body posture, and aggression (Beerda, et al., 1998; Rooney, et al., 2007 ).

Conflict behaviours arise when the animal is undergoing two equally high but conflicting motivational states, or when the environment frustrates the performance of a highly motivated behaviour (Luescher, 2000). An instance of conflict behaviour seen in the veterinary clinic is found in the friendly dog that is also fearful i.e., the dog has a conflict between the motivation to approach clinic personnel and the motivation to avoid them. This may result, at the least, in the animal being in a high state of arousal and thus more likely to behave aggressively, or to struggle. The fact that the animal is usually restrained or confined in the veterinary environment, which is unpredictable and uncontrollable from the patient's point of view, exacerbates their inner conflict. In some individuals, being in ongoing situations of this kind result in stereotyped coping behaviours and a reduced arousal threshold. These behaviours can include tail-chasing, walking or running in a circle, 'star-gazing' and 'fly-snapping'.

Rodents

Caged rodents are typically provided with a running wheel. They normally use it so extensively that the behaviour might be considered compulsive or a sign of stress or environmental inadequacy. Research to date suggests that, while the persistence of the behaviour and the exercise involved is unlike anything seen in the wild, the behaviour is probably not a welfare concern (Sherwin 1998). Of more concern in caged rodents are the common behaviours of bar-biting (mice, gerbils, hamsters) and digging (gerbils). Research suggests that those behaviours are a response to the frustration of being confined in too small a space that does not satisfy basic behavioural needs (Wurbel, 2001) such as burrowing (hamsters; Fischer, et al., 2007, Hauzenberger, et al., 2006), digging and/or having access to a darkened tunnel (gerbils; Wiedenmayer, 1997). It is likely that many pet rodents may fare less well than their counterparts in laboratories because research on the latter is leading to stricter requirements for their housing (e.g., in Switzerland, a minimum of 30 cm (~14") of bedding is required for golden hamsters used in the lab.(Hauzenberger, et al., 2006).

Raising Standards

More generally, as national legislation specifying the duties of animal caregivers' becomes more common, it will be important for veterinarians to be aware of stress in their patients and to advise owners accordingly. A theoretical example under new UK legislation is that a rodent owner could be held liable for keeping their animal in conditions that could lead to suffering (e.g., a hamster in a small cage). If you had seen the cage and failed to advise the owner about using a larger cage with deeper bedding, they could sue you for negligence (c.f. Yeates, 2008). Whether or not such laws are in place, we can raise our standards of care even higher by paying closer attention to signs of stress in our patients and by having policies to make their time at the clinic or in the hospital as pleasant as possible.

References

1.  BCSPCA. The Emotional Life of Cats. Vancouver: British Columbia Society for the Prevention of Cruelty to Animals. 2004

2.  Beerda B, Schilder MBH, van Hooff JARAM, de Vries HW, Mol JA. (1998). Behavioural, saliva cortisol and heart rate responses to different types of stimuli in dogs. Applied Animal Behaviour Science 58: 365-381.

3.  Dybdall K, Strasser R, Katz T. (2007). Behavioral differences between owner surrender and stray domestic cats after entering an animal shelter. Applied Animal Behaviour Science 104: 85-94.

4.  Fischer K, Gebhardt-Henrich SG, Steiger A. (2007). Behaviour of golden hamsters (Mesocricetus auratus) kept in four different cage sizes. Animal Welfare 16: 85-93.

5.  Gregory NG. (2004). Physiology and Behaviour of Animal Suffering pp 12-21. Oxford: Blackwell.

6.  Hauzenberger AR, Gebhardt-Henrich SG, Steiger A. (2006). The influence of bedding depth on behaviour in golden hamsters (Mesocricetus auratus). Applied Animal Behaviour Science 100: 280-294.

7.  Kessler MR, Turner DC. (1997). Stress and adaptation of cats (Felis silvestris catus) housed singly, in pairs and in groups in boarding catteries. Animal Welfare 6: 243-254.

8.  Luescher A. Compulsive behavior in companion animals (22 September 2000). In: Recent Advances in Companion Animal Behavior Problems, Houpt K.A. (Ed.) Publisher: International Veterinary Information Service (http://www.ivis.org/). Available from http://www.ivis.org/advances/Behavior_Houpt/luescher/IVIS.pdf. Last accessed: March 30 2008.

9.  Rooney NJ, Gaines SA, Bradshaw JWS. (2007) Behavioural and glucocorticoid responses of dogs (Canis familiaris) to kenneling: Investigating mitigation of stress by prior habituation. Physiology and Behaviour 92:847-54.

10. Sherwin C. (1998). Voluntary wheel running: a review and novel interpretation. Animal Behaviour 56: 11-27.

11. Välsänen AM, Valros AE, Hakaoja E, Raekallio MR, Vainio OM. (2005). Preoperative stress in dogs--a preliminary investigation of behavior and heart rate variability in healthy hospitalised patients. Veterinary Anaesthesia and Analgesia 32: 158-167.

12. Wiedenmayer C. (1997) Causation of the ontogenetic development of stereotypic digging in gerbils. Animal Behaviour 53, 461-470

13. Wurbel H. (2001). Ideal homes? Housing effects on rodent brain and behaviour TRENDS in Neurosciences 24: 207-210.

14. Yeates J. (2008) Everyday Ethics. Obese dog. In Practice 30: 173-174.