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Age-Related Changes in the Cardiothoracic Ratio of Juvenile Japanese Macaques (Macaca fuscata)
Yuto Sawada1, Akihisa Kaneko2, Naohide Ageyama3
1Laboratory of Laboratory Animal Science, Azabu University, School of Veterinary Medicine, Sagamihara, Kanagawa, Japan.
Background:
Evaluation of the cardiothoracic ratio (CTR) using chest radiography is a valuable tool for screening cardiac diseases; however, age-related changes in CTR remain unclear, particularly in Japanese macaques. This study assessed the CTR in juvenile Japanese macaques and examined its relationship with age and sex.
Materials And Methods:
CTR was calculated from chest radiographs of juvenile macaques aged 1-4 years and compared with those of adults. Correlations between CTR and age in months and differences between sexes were analyzed.
Results:
Juvenile macaques showed a significantly higher CTR than adults. A significant negative correlation was observed between age and CTR. No significant sex-related differences in CTR were observed across ages.
Conclusions:
The CTR in Japanese macaques decreases with age, indicating that age-specific reference values are essential for accurately assessing cardiac size in juvenile individuals. These findings will contribute to the early detection and management of cardiac diseases in juvenile Japanese macaques.
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