Changes in body weight and body surface area in strain 13 guinea pigs infected with Pichinde virus

In studying pathogenetic mechanisms of Pichinde virus-induced disease in strain 13 guinea pigs, a large decrease of body weight (approximately 28%) observed within 14 days postinoculation raises a question concerning the validity of standardizing body or organ functions in terms of body weight. This study was to examine changes in body weight and body surface area of Pichinde virus-infected strain 13 guinea pigs after various days postinoculation. Control guinea pigs were also subjected to the same experimental procedures and experimental days. While body weights and body surface areas increased progressively in controls, I observed only slight decreases in body surface areas (4-6%) in the infected guinea pigs, despite large decreases of body weights throughout the 14-day experimental period. In conclusion, Pichinde virus-infected strain 13 guinea pigs demonstrated a small reduction of body surface area within 14 days postinoculation, suggesting that body surface area, rather than body weight, should be used for standardizing body or organ functions for comparison with their own baseline values.