Olfactory stimulus as environmental enrichment for shelter dogs: a pilot study
Keywords:Canis lupus familiaris, Environmental enrichment, Olfactory stimulus, Scents, Shelter
Environmental enrichment techniques include olfactory stimuli for improving animal welfare. This study aimed to analyze the reactions of 41 shelter dogs exposed to odorous stimuli, such as the method used in another study on wild canids. The focal animal method analyzed the dogs’ reactions, with all behaviors recorded. Behavioral responses were classified as positive (P+), negative (N-), or other (Ot). Independent variables were all dogs and the size of the packs. The behavior between the basal (without stimulus), exposure, and after-stimulus withdrawal was analyzed. For all dogs, olfactory stimuli significantly increased P+ (P=0.001) and N- (P=0.004), contrasting with the decrement of Ot behaviors (P=0.001) from the basal to the exposure phase. After the withdrawal of the stimuli, P+, N-, and Ot behaviors returned to basal levels (P>0.05). There were no significant differences (P>0.05) in the conduct of small or large packs exposed to stimuli. Dogs are sensitive to olfactory stimuli, but arousal is generalized to P+ and N-. It is undesirable to an N- increase for improvement of animal welfare. Contrary to what was observed in a study with wild canids, the method failed in shelter dogs because N- was increased. The introduction of sudden novelty (olfactory stimulus) in an impoverished shelter environment may have caused excitement in the dogs. It is suggested that changes in the method, such as stimuli exposition to each dog in an isolated room, are necessary to increase sheltered dog well-being.
Breuer J, Elson M. Frustration-aggression theory. In: Sturmey P, editor. The Wiley handbook of violence and aggression. Chichester: Wiley; 2017. http://dx.doi.org/10.1002/9781119057574.whbva040.
Conde C, Costa V, Tomaz C. PROSTCOM: um conjunto de programas para registro y procesamiento de datos comportamentales em investigaciones de fisiologia y farmacologia. Biotemas. 1999;13(1):145-59. http://dx.doi.org/10.5007/%x.
De Briyne N, Vidović J, Morton DB, Magalhães-Sant’ana M. Evolution of the teaching of animal welfare science, ethics and law in European veterinary schools (2012-2019). Animals. 2020;10(7):1238. http://dx.doi.org/10.3390/ani10071238. PMid:32708281.
Duranton C, Horowitz A. Let me sniff! Nosework induces positive judgment bias in pet dogs. Appl Anim Behav Sci. 2019;211:61-6. http://dx.doi.org/10.1016/j.applanim.2018.12.009.
Figueira MP, Silva FFR, Ribeiro A, Silva IO, Boere V. The behavioral response of the crab-eating fox to olfactory enrichment. Appl Anim Behav Sci. 2021;242:105430. http://dx.doi.org/10.1016/j.applanim.2021.105430.
Graham L, Wells DL, Hepper PG. The influence of olfactory stimulation on the behaviour of dogs housed in a rescue shelter. Appl Anim Behav Sci. 2005;91(1-2):143-53. http://dx.doi.org/10.1016/j.applanim.2004.08.024.
Green PA, Van Valkenburgh B, Pang B, Bird D, Rowe T, Curtis A. Respiratory and olfactory turbinal size in canid and arctoid carnivorans. J Anat. 2012;221(6):609-21. http://dx.doi.org/10.1111/j.1469-7580.2012.01570.x. PMid:23035637.
Horowitz A, Franks B. What smells? Gauging attention to olfaction in canine cognition research. Anim Cogn. 2020;23(1):11-8. http://dx.doi.org/10.1007/s10071-019-01311-z. PMid:31606800.
Kouremenou I, Piper M, Zalucki O. Adult neurogenesis in the olfactory system: improving performance for difficult discrimination tasks? BioEssays. 2020;42(10): 2000065. http://dx.doi.org/10.1002/bies.202000065. PMid:32767425.
Lowe A, Dalton M, Sidhu K, Sachdev P, Reynolds B, Valenzuela M. Neurogenesis and precursor cell differences in the dorsal and ventral adult canine hippocampus. Neurosci Lett. 2015;593:107-13. http://dx.doi.org/10.1016/j. neulet.2015.03.017. PMid:25778416.
Ming G, Song H. Adult neurogenesis in the mammalian brain: significant answers and significant questions. Neuron. 2011;70(4):687-702. http://dx.doi.org/10.1016/j.neuron.2011.05.001. PMid:21609825.
Newberry RC. Environmental enrichment: increasing the biological relevance of captive environments. Appl Anim Behav Sci. 1995;44(2-4):229-43. http://dx.doi.org/10.1016/0168-1591(95)00616-Z.
Newbury SP. Guidelines for standards of care in animal shelters. Camas, WA: The Association of Shelter Veterinarians; 2010. 64 p.
Teixeira CP, Barçante L, Azevedo CS. Comportamento animal: uma introdução aos métodos e à ecologia comportamental. Rio de Janeiro: Appris Editora e Livraria Eireli-ME; 2018. 221 p.
Tuber DS, Miller DD, Caris KA, Halter R, Linden F, Hennessy MB. Dogs in animal shelters: problems, suggestions, and needed expertise. Psychol Sci. 1999;10(5):379-86. http://dx.doi.org/10.1111/1467-9280.00173.
Wells DL. Sensory stimulation as environmental enrichment for captive animals: a review. Appl Anim Behav Sci. 2009;118(1- 2):1-11. http://dx.doi.org/10.1016/j.applanim.2009.01.002.
Wells D, Hepper PG. Prenatal olfactory learning in the domestic dog. Anim Behav. 2006;72(3):681-6. http://dx.doi.org/10.1016/j.anbehav.2005.12.008.
Young RJ. Environmental enrichment: an historical perspective. In: Young RJ, editor. Environmental enrichment for captive animals. Great Britain: Universities Federation for Animal Welfare; 2003. http://dx.doi.org/10.1002/9780470751046.ch1.
van der Borg JAM, Schilder MBH, Vinke CM, De Vries H. Dominance in domestic dogs: a quantitative analysis of its behavioural measures. PLoS One. 2015;10(8):e0133978. http://dx.doi.org/10.1371/journal.pone.0133978. PMid:26309101.
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