Final answer:
Pregnancy toxemia is the disease seen in ewes carrying multiple fetuses that results from ketosis, typically occurring in the third trimester due to increased energy demands.
Step-by-step explanation:
The disease seen in ewes carrying twins or triplets that results from ketosis is d. Pregnancy toxemia. This condition occurs during the late stages of pregnancy, particularly the third trimester, when the energy demands are increased due to the growth of the fetuses. The ewes cannot intake enough nutrition to support both their own metabolic needs and those of the growing fetuses, leading to excessive breakdown of body fats and the overproduction of ketone bodies, resulting in ketoacidosis. This condition can be serious and lead to a decrease in blood pH and milk production, among other symptoms.