Runt

Biography & Overview

A runt is an animal that is unusually small for its species. In veterinary medicine, a runt may also be described using terms such as low-birth weight, intrauterine growth restriction (IUGR), and small for gestational age (SGA). An animal may be defined as small for gestational age depending on different criteria, such as size in comparison to littermates', as percent of maternal body weight, as a specific neonate weight threshold for the breed or species, and as different body proportions displayed by runts. Runts face many challenges in comparison to their normal birth weight peers—they are more likely to contract diseases, and die in the neonatal period, have lower glycogen stores, have developmental delays, insulin resistance, hypothermia, and low blood pressure.