The nucleus in a typical human cell is made of 23 pairs of chromosomes. According to the National Down Syndrome Society, “Down syndrome occurs when an individual has a full or partial extra copy of chromosome 21.”
Although many animals have a different number of chromosomes in their nuclei, an extra full or partial chromosome can have an effect that is similar to its effect in humans. Animals can have a range of degrees of Down syndrome – just like humans. Here are 45 animals with Down syndrome who will melt your heart.