Nesting materials may cause pneumonia-like findings in Sprague Dawley rats

Aim/Background: In the studies conducted with laboratory animals, using wood shavings as cage nesting material may have an impact on study results. However, there is not sufficient information on the effects on lungs due to using wood shavings. We have aimed to radiologically and histopathologically examine possible lung pathologies, which can be seen on laboratory animals in which wooden shavings are used as filling materials. Method: In this study, 20 male Sprague Dawley rats have been divided into two groups and put into the cages one by one with and without filling materials. At the beginning and end of the four-week monitoring process, their lung radiographies have been taken. Additionally, their lung tissues have been histopathologically examined at the end of the study, and ion chromatography and gas chromatography mass spectrometry analyses were performed. Results: Pneumonia-like findings were detected in the lungs of animals in cages where wooden shavings are used, and diagnosis has been confirmed histopathologically. Chlorate has been detected both in lungs of animals for which pathology has formerly been detected and in wooden shavings used; 2,2'-methylenebis[6-(1,1-dimethylethyl)-4-methyl has also been detected in wood shavings and pathological lungs. Conclusions: Detected chemicals may contribute to the lung pathology, which is seen on animals in which wooden shavings are used as filling material. It was concluded that avoiding wooden shavings as filling material in the experimental studies conducted with laboratory animals is going to be more reasonable in terms of reliability of results and health of animals.