Mastication involves rhythmic and voluntary movements of lower jaw by the masticatory muscles. Tooth loss and weakness of masticatory muscles causes impairment of masticatory function and chewing disability (Teixeira et al 2014).
Animal experiments have shown that tooth loss or long-term soft-diet feeding causes a decrease in learning and memory ability (Wanabe et al 2002) Another study also revealed that soft-diet feeding after a weaning period reduces synaptic formation in the cerebral cortex and impairs the ability of spatial learning in the adulthood hypothalamus ( Onozuka et al 2002; Teixeira et al 2014). ). Biting during restraint exposure suppresses stress-induced catecholamine concentrations and therefore responses are reduced. This implies that masticatory activity induced a positive anti-stress effect in animals (cited in Frota de Almedia. Et al 2012). Therefore if a dog has been exposed to uncontrollable stressors, it might be beneficial to give the dog something to chew on.
Mastication is regulated by a neural population in the brainstem and a neural network including several brain regions. Chewing has been shown to be associated with increased cerebral blood flow, and several studies have reported increased cerebral activity following gum chewing in humans. Thus, the beneficial effects of chewing on cerebral activity have been suggested, because chewing uses the same neural pathways as cognition so pathways are less likely to decay if chewing is maintained (Sasaki-Otomaru et al 2012; Onozuka et al 2002).
In epidemiological studies, oral function and status have been shown to be related to physical, mental, and social health. In particular, chewing ability has been shown to influence activities of daily living, cognitive status and quality of life (Frota de Alemdia et al 2012).
Therefore chewing is a fantastic way to ensure that the dogs jaw muscles are exercised regularly.
Chewing may have a relaxing effect for the dog aswell as the other benefits described above. Play is defined by the oxford dictionary(2014) “to engage in an activity for enjoyment and recreation rather than a serious or practical purpose” therefore the chewing of can be deemed play, solitary play, and for interacting with as demonstrated in the following video.
A Kong is flexible dog toy which the dog can bite down animal experiments have shown this activity induced a positive anti-stress effect in animals (cited in Frota de Almedia. Et al 2012). Therefore if a dog has been exposed to uncontrollable stressors, it might be beneficial to give the dog a kong to carry with them, it seems to act as a dummy and can be reassuring to a dog.
Frota de Almedia. Et al (2012) Spatial memory decline after masticatory deprivation and aging is associated with alterd laminar distribution of CA1 astrocytes. BMC Neuroscience (2012) volume 13: no 23
Onozuka M, Watanabe K, Fujita M, Tonosaki K, Saito S. (2002) Evidence for involvement of glucocorticoid response in the hippocampal changes in aged molarless SAMP8 mical e. Behavioural Brain Research. 2002;131:125-129
Oxford dictionary (2014) Oxford Dictionary Of English .version 1.6 Anthony Lewis: Wordweb software.
Sasaki-Otomaru, A. Sakuma, Y Sato, C. (2011) Effect of Regular Gum Chewing on Levels of Anxiety, Mood, and Fatigue in Healthy Young Adults Clinical Practice & Epidemiology in Mental Health, 2011, Vol. 7, pp. 133-139.
Teixeira, F. Fernandes, L Noronha, P et al (2014) Masticatory Deficiency as a Risk Factor for Cognitive Dysfunction International Journal of Medical Sciences
Wanabe Et al The molarless condition in aged SAMP8 mice attenuates hippocampal Fos induction linked to water maze performance Behavioural Brain Research 2002; 128: 19-25