1. Olfactory Effects of Husbandry on Laboratory Mouse Welfare
Noelia Lopez-Salesansky1,2, Dominic Wells1, Lucy Whitfield1, Cathy Fernandes3 and Charlotte C. Burn2
1 Royal Veterinary College, Royal College Street, London NW1 0TU, UK; 2 Royal Veterinary College, Hawkshead Lane, Herts AL9 7TA, UK; 3 Social, Genetic & Developmental Psychiatry Centre, Institute of Psychiatry, King’s College London
Introduction
Mice perceive the world differently to humans, using olfaction as their main sensory input1. Scents of other animals and chemicals found in the laboratory could produce stress and defensive behavioural responses that could reflect the welfare status of the animals2.
A survey of U.K. laboratory animal units3,4 (1) revealed a high variability of the olfactory environment mice encounter. Four experiments were performed to investigate whether handling (2) or cleaning practices (3) affected behavioural welfare indicators. Results will help refine husbandry practices.
(A) Glove Materials : Mice (N=24: six female C57BL/6J mice and eight males; 6 female DBA/2J mice and four males) were handled with Nitrile or Latex gloves or with a bare hand (Figure 2).
(B) Handling other mice: Mice (N=32, C57BL/6J, 16 per sex) were exposed to, and handled with, gloves used to handle other mice (C57BL/6J mice and Balb/c mice of both sexes) (Figure 3). A C
Most (70%) respondents wore gloves to handle mice with 30% reporting occasionally handling them with bare hands. When gloves were used Nitrile was the most common (70%) glove material followed by Latex (17%). TrigeneTM (later named AnistelTM) was the most common product used for most cleaning practices. 77% or respondents reported that hands were not washed and gloves were not changed between handling male and female mice, B
Survey of olfactory variation across UK laboratories
Figure 2 Interaction with the hand using Nitrile (A) or Latex (B) gloves or a bare hand (C).
2) Handling practices
The aim of these experiments was to determine whether (A) the glove material (B) handling mice of different strains and sexes without changing gloves or (C) spraying gloves with alcohol affected mouse welfare before during or after handling. We hypothesised that if handling practices were perceived as aversive they would reduce hand interaction5, affect handleability6, cause stress/defensive behaviours (e.g. defensive burying 7, altered grooming pattern8, increased wall rearing9), affect affiliative behaviours10 or cause stereotypies in the home cage11 (Figure 1). In all experiments mice were handled using the cupping method described by Hurst. et. al 5 and habituated to the treatments to avoid novelty-induced behaviours. Observations were made before, during and after handling and in the home cage.
Figure 3 Different steps of the experiment when handling other mice
(C) Spraying gloves with alcohol: Mice (N=32 C57BL/6J mice,16 males and 14 females; N=22 Balb/c mice, 10 males and 10 females) were exposed to, and handled with, gloves sprayed with alcohol or not. A B
Results: Depending on the strain and sex, mice showed signs of aversion (avoidance, defensive burying, increased wall rearing) after being handled with a bare hand or with a glove sprayed with alcohol. Handling unfamiliar mice of a different strain initiated fights in the home cage amongst group housed male mice. In contrast, spraying gloves with alcohol reduced aggression immediately after handing increasing grooming. C D
3) Cleaning Practices
The aim of these experiments was to determine whether (A) cleaning the Open Field with different cleaning products (Trigene, Alcohol, Virkon or Wiping with water) affected traditional measures of anxiety (increased thigmotaxis) or induced behavioural indicators of stress/anxiety (altered grooming pattern, increased wall rearing) and (B) whether mice showed a preference towards a cleaning product in the radial maze.
Figure 1 Mice showing (A) sniffing, (B) defensive burying, (C) digging and (D) wall rearing
Results: Cleaning products did not affect measures of anxiety in the open field but wiping the arena with water increased defecation and decreased rearing suggesting that it did not remove pheromonal cues. No preference or avoidance was seen in the radial maze.
References
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Hurst, (2010), Nature Methods,
Burn, 2006, Lab Anim, 353–370.
De Boer, (2003), European Journal of Pharmacology, 463(1-3),
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Mason (2004), Animal Welfare,2(4), .
Conclusions
We recommend avoiding handling mice with bare hands and spraying gloves with alcohol as these practices suggest welfare compromise. Wiping behavioural equipment with water could induce behavioural and physiological changes associated with pheromonal communication
Acknowledgements: This work has been funded by the Chistopher Went Scholarship and was supported with UFAW funding for consumable materials.