FEB 04, 2016 03:00 PM PST

Problems when breeding laboratory mice: why are pups dying?

  • Postdoctoral Research fellow, Comparative Medicine, Stanford University
      Elin Weber is a postdoctoral research fellow at Stanford University. She has a MSc in Biology from Gothenburg University and received her PhD in Ethology at the Dept. of Animal Environment and Health, Swedish University of Agricultural Sciences in 2015.

      Dr Weber's research focus on welfare of laboratory animals. She has worked with laboratory animals since she did her master in 2005 at the Institute for Molecular and Cell Biology in Porto, Portugal. Her main research interest is applied ethology, especially how knowledge about the animals' natural behavior can improve well-being of the animals. Previous work has mainly focused on maternal behavior and problems with reproduction in laboratory mice, with emphasis on the effect of housing environment. Her present research on welfare in laboratory mice includes designing housing that meets the behavioral needs of laboratory mice within the restrictions of the laboratory environment. Dr. Weber is regularly involved in educating researchers in ethology and welfare of laboratory animals. Besides ethology and animal welfare, her research also involves animal ethics.

      Mouse Ethogram: www.mousebehavior.org


    A crucial part of providing animals for research is successful breeding. Still, in many mouse facilities breeding efficiency is complicated by problems with reproduction, such as pre-weaning pup mortality. Both single pups and the entire litter can be lost, with loss of entire litters having the most substantial influence on breeding efficiency. Although pup mortality is a relatively common problem, the underlying causes are poorly understood. Since dead mouse pups are often eaten by their mother, there is a widespread belief that the female actively kills them, and that leaving mothers undisturbed will prevent the mothers from killing their pups. Another common assumption is that it is normal for laboratory mice to lose their first litter due to the mother being inexperienced. However, the scientific support for these assumptions are insufficient. 

    This presentation will provide information on pup mortality in laboratory mice based on scientific data from studies examining the cause of litter loss, and give recommendations on how pup mortality can be reduced. Use of the terms cannibalism and infanticide will also be discussed and the importance of finding the real cause of pup mortality instead of assuming why pups die will be stressed.

    Show Resources
    Loading Comments...