Enrichment & Recovery
Amanda Griffiths BSc (Hons)
Recent research has shown that consideration of an animals environment following injury, illness or surgery can have a significant impact on their recovery. In this review we look at stress and the mechanisms through which it impacts recovery along with how environmental enrichment may help to reduce stress and improve recovery, and how this may be beneficial for dogs on a period of crate rest or restricted exercise.
Stress can occur as a result of psychological, environmental and physical stressors (1). When an animal requires veterinary treatment, hospitalisation, or have a long term condition causing pain or impacting their quality of life the animal can be subject to all three types of stressors as a result. Stressful events can include the vetertinary surgery enrvironment, any treatment required (2), the accident or injury itself, pain and any crate rest/ restricted exercise during recovery.
A review by Hekman et al looked at the impact of stress in hospitalised dogs. The review found that the veterinary hospital environment can cause both physiologic stress and psychogenic stress. Physiologic stress occurs as a result of physical or environmental changes and can include illness, injury or surgery. There are also a range of things that can cause psychogenic stress such as seperation from the owner, a strange environment and any treatment procedures required.
Stress that results from an injury, illness, surgery or long term health condition is considered chronic stress as it lasts more than a few hours. When stress becomes chronic it begins to have a negative impact on the immune system and is immunosupressing, as oppose to the immunoenhancing effect that results from acute stress. Hekmans review also found that the time the stressor occurs in relation to the injury/ illness plays an important role. If the stress occurs after the event that initiated the immune response it's more likely to result in an immunosuppresive effect, whereas if the stressful event occured prior to immune response the effect is more likely to be immunoenhancing. In terms of recovery, this means that if an animal is recovering in an environment they find stressful then this is likely to supress their immune system.
Stress also has a well documented impact on wound healing, the cardiovascular system and gastrointestinal system.
Recent studies have shown that providing environmental enrichment during recovery can relieve depression and anxiety, and also decrease perception of pain (3, 4, 5, 6). A study by Moncek et al found that providing environmental enrichment to rats resulted in pronounced changes in neuroendocrine regulation. The rats provided with environmental enrichment showed lower resting plasma levels of adrenocorticotropic hormone, and lower levels of corticosterone and adrenaline in response to stress in relation to controls. This is supported by a study of mice by Vachon et al 2013, which showed that providing enrichment to healthy mice decreases behaviours associated with anxiety, while social isolation increased behaviours associated with anxiety. A study by Seong et al looked at the effect of environmental enrichment on stress induced depression in rats. This study found that providing environmental enrichment was as effective as flouxetine, as SSRI, in reducing the behavioural and biochemical changes associated with stress-induced depression.
Studies have also shown that environmental enrichment can impact perception of pain. A study by Vachon et al 2018 looked at the effect of environmental enrichment in rats with neuropathic pain, and found that rats provided with environmental enrichment showed less pain associated behaviours than controls not provided with enrichment. Studies have also shown that rats in an environmentally enriched environment recover more quickly from local joint inflammation than controls, and also show less hypersenstivity. This study also showed that environmental enrichment improves sensory and motor dysfunction in rats after spinal cord injury. To futher support the pain relieving effect of environmental enrichment, a study of post-operative mice showed that mice provided with environmental enrichment reduces analgesic drug self-administration compared to controls (5).
This research suggests that providing envrionmental enrichment to dogs during recovery, such as a period of crate rest or restricted exercise, is likely to ease stress, decrease recovery times and may even have beneficial effects in pain management. By decreasing stress, we can help to prevent the negative impact it has on the systems mentioned above such as the immune sytem, gastrointestinal system and cardiovascular system.
A range of studies have looked at the benefits of the addition of enrichment activities for dogs in kennel environments (7,8), but there is currently no research looking specifically at the use of enrichment during recovery in dogs and the impact it may have so this is an area for future study.
Alongside the potential benefits of enrichment on recovery and pain management, minimising stress has it's own benefits. Our own market research has shown that owners with dogs on crate rest commonly struggle with barking, whining, overexcitability & hyperactivity, compulsive behaviours and destructive behaviours such as chewing and digging. A review by Stuart Greenfield on managing stressed canines suggests that supporting owners by advising them on the importance of mental stimulation can help to increase owner compliance with crate rest/ restricted exercise. If the dog is calm and happy, rather than showing the stress-related behaviours listed above owners are more likely to follow crate rest and exercise advice more strictly, and this in turn helps to prevent the complications or increased recovery times associated with dogs that have done too much exercise against veterinary advice (9).
References and further reading
1. Karl J.P, Hatch A.M, Arcidiacono S.M, Pierce S.C, Pantoja-Feliciano I.G, Doherty A.L, Soares J.W. 2018 'Effects of Psychological, Environmental and Physical Stressors on the Gut Microbiota' Frontiers in Microbiology 9:2013
2. Hekman J.P, Karas A.Z, Sharp C.R. 2014 'Psychogenic Stress in Hospitalized Dogs: Cross Species Comparisons, Implications for Health Care, and the Challenges of Evaluation' Animals (Basel) 4(2):331-347.
3. Seong H.H, Park J.M, Kim Y.J. 2018 'Antidepressive Effects of Environmental Enrichment in Chronic Stress-Induced Depression in Rats.' Biological Research for nursing 20(1):40-48
4. Vachon P, Millecamps M, Low L, Thompsosn SJ, Pailleux F, Beaudry F, Bushnell CM, Stone LS. 2013. 'Alleviation of chronic neuropathic pain by environmental enrichment in mice well after the establishment of chronic pain.' Behavioural and Brain Functions 7;9:22
5. Vachon P, Parent-Vachon M. 2018. 'Environmental Enrichment alleviates chronic pain in rats following a spared nerve injury to induce neuropathic pain. A preliminary study' Vet Med (Auckl) 9:69-72
6. Moncek F, Duncko R, Johansson BB, Jezova D. 2004 'Effect of environmental enrichment on stress related systems in rats.' Journal of neuroendocrinology 16(5):423-431
7. Schipper L.L, Vinke C, Schilder M.B.H, Spruijt B.M. 2008 'The effect of feeding enrichment toys on the behaviour of kennelled dogs (Canis familiaris)'. Applied Animal Behaviour Science 114 (1-2): 182-195.
8. Herron M.E, Kirby-Madden T.M, Lord L.K. 2014 'Effects of environmental enrichment on the behavior of shelter dogs' Journal of the American Veterinary Medical Association 15;244(6):687-92
9. Greenfield S. 2013 'Managing Stressed Canines: Practical Techniques' Vet Times https://www.vettimes.co.uk/app/uploads/wp-post-to-pdf-enhanced-cache/1/managing-stressed-canine-patients-practical-techniques.pdf