Can a mare carry foal for more than 365 days?

No, a mare cannot carry a foal for more than 365 days. The average gestation period for a mare is 340 days, with a range of 320 to 370 days. A gestation period longer than 365 days is considered to be abnormal and is known as prolonged gestation. Prolonged gestation can be caused by a variety of factors, including:

* Placental insufficiency: This occurs when the placenta, which provides nutrients and oxygen to the fetus, does not function properly. Placental insufficiency can be caused by a number of factors, including infection, trauma, and malnutrition.

* Fetal abnormalities: Certain fetal abnormalities, such as a large head or a hydrocephalic skull, can make it difficult for the fetus to be delivered.

* Maternal factors: Certain maternal factors, such as obesity and uterine inertia, can also contribute to prolonged gestation.

Prolonged gestation can be dangerous for both the mare and the foal. The mare may experience uterine rupture, and the foal may be born prematurely or with health problems. If you think your mare may be experiencing prolonged gestation, it is important to contact your veterinarian immediately.