How much should a rat weigh at two months? - briefly
A typical two‑month‑old laboratory rat weighs between 150 g and 300 g, with variations depending on strain and sex. Pet rats of similar age often fall within the same range.
How much should a rat weigh at two months? - in detail
A two‑month‑old rat typically weighs between 150 g and 250 g, but the exact figure depends on strain, sex, nutrition, and husbandry conditions.
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Strain differences
• Sprague‑Dawley: 180–220 g
• Wistar: 170–210 g
• Long‑Evans: 150–190 g -
Sex influence
Males usually exceed females by 10–20 g at this age. -
Dietary impact
Standard laboratory chow provides 3.0–3.5 kcal g⁻¹; ad libitum feeding yields weights at the upper end of the range, while restricted diets shift values downward by 5–15 g. -
Environmental factors
Ambient temperature (22–24 °C) and cage density affect metabolic rate; overcrowding can reduce growth by 5 g or more.
Weight should be recorded with a calibrated balance to the nearest gram. A single measurement outside the expected interval does not necessarily indicate pathology, but persistent deviation (>20 g below the lower limit) warrants health assessment for malnutrition, parasitism, or disease. Regular monitoring allows early detection of growth abnormalities and ensures appropriate care.