Abstract
AbstractNeonatal mortality in wild-type laboratory mice is an overlooked welfare and financial problem in animal facilities around the world. Causes of death are often not reported and its causes remain unknown.In this study, 324 newborn pups from two breeding colonies of healthy wildtype C57BL/6 mice underwent post-mortem analysis with special focus on obtaining proof of life after birth, evaluation of stomach contents and observation of congenital abnormalities that could compromise survival.Based on a combination of lung morphology findings, outcome of lung float test, stomach contents and brown adipose tissue colouration, 21.6% of the pups found dead were considered stillbirths. Of the livebirths, only 3.2% were observed to have milk inside the stomach, indicating successful suckling. Congenital abnormalities were diagnosed only in a small fraction of the pups analysed. These results suggest that starvation was the most common cause of death, followed by stillbirth.
Publisher
Cold Spring Harbor Laboratory
Reference50 articles.
1. How does a newly born mouse get to the nipple? odor substrates eliciting first nipple grasping and sucking responses;Developmental Psychobiology,2013
2. Bolon B. Pathology of the Developing Mouse: A Systemic Approach. 1st ed. Boca Raton, FL, USA: CRC Press, 2015.
3. Social environment as a cause of litter loss in laboratory mouse: A behavioural study;Applied Animal Behaviour Science,2019
4. Brayton C. Chapter 25 - Spontaneous Diseases in Commonly Used Mouse Strains. In: Fox JG , Davisson MT , Quimby FW , et al. (eds) The Mouse in Biomedical Research (Second Edition). Burlington: Academic Press, 2007, pp.623–717.
5. Buonfiglio DC , Ramos-Lobo AM , Freitas VM , et al. Obesity impairs lactation performance in mice by inducing prolactin resistance. Scientific Reports 2016.