Meaghan Loy, Category Director of In Vivo Services at Scientist.com and member of the North American 3Rs Collaborative Board of Directors, interviewed fellow members of the NA3RsC to discuss the traditional method of mice handling and how these methods are shifting towards a new and more efficient approach.

ML: How are mice traditionally handled?

Mice are traditionally handled by picking them up by the tail.

ML: What inspired you to investigate refinement in mouse handling?

It was by chance that I started using the tube method to move mice during cage cleaning and research projects. For various research projects, I housed male and female mice singly, or in same-sex pairs or groups of four and cleaned their cages during the research project. For environmental enrichment, I provided cardboard tubes in all the cages. When I attempted to pick the mice up by the tail, they would often run into the tube, so I began moving them to a clean cage or handling them during research projects with the tube instead of by the tail.

I saw some videos and posters about it and was interested in the benefits to our animals.

“The tube handling method has broad benefits. For example, it saves time spent ‘chasing’ mice to grab their tail, and this in turn reduces overall handling stress for mice and frustration experienced by handlers.”

ML: What are the benefits of refined handling when compared to traditional handling?

The refined tube handing method saves time. Mice often run away from a hand that approaches them, and time can be spent ‘chasing’ a mouse to grab his/her tail – even for experienced handlers. The tube method avoids this issue. I used the tube method successfully with young adult and older Swiss Webster and C57Blk mice.

Mice appear calmer and more likely to interact with the hand voluntarily.

Less stressed animals and better scientific data.

ML: How can technicians learn these new techniques? Who can teach them?

If your institution currently offers a mouse handling training workshop, but refined methods are not included in the training, talk to the workshop organizer, your Animal Care Supervisor, Attending Veterinarian or IACUC about including refined methods in the workshop. If your institution does not have a mouse handling training workshop, talk to the same people about providing this valuable training and to include refined handling methods.

Using the NC3Rs videos as well as hands-on how we put it into practice with our caging and hood set up.

ML: How can these techniques be implemented on a larger scale?

A time efficient way to implement the tube handling method is to keep tubes in home cages for environmental enrichment. Mice prefer dark areas and near-opaque tubes (colored plastic) or opaque tubes (e.g., cardboard); they naturally become a safe place for mice to retreat. Handlers can take advantage of this preference to implement tube handling methods during cage cleaning or handling during research projects.

For cage cleaning, mice can be picked up in tubes already present in their home cage and then placed into a clean cage with clean tubes. For research projects, mice can be lifted out of their home cage in the tube and dropped into a cupped hand and repositioned for a procedure and/or moved to test apparatus.

It’s the whole set up that needs thinking of, including how you remove the bedding or food hopper and still keep the area sterile/not cross contaminate.

Ensure that it is included in the policies and training plans/ records.

ML: Does the new method take more time or cost more?

The tube handling method has broad benefits. For example, it saves time spent ‘chasing’ mice to grab their tail, and this in turn reduces overall handling stress for mice and frustration experienced by handlers.