Final answer:
It is essential to monitor for preeclampsia in pregnant guinea pigs, as it is a severe pregnancy-related condition that can affect the health of both the mother and the offspring.
Step-by-step explanation:
When breeding guinea pigs, it is important to watch for the condition of preeclampsia in pregnant animals. Preeclampsia is a serious pregnancy complication characterized by high blood pressure and signs of damage to another organ system, often the kidneys. Pregnant guinea pigs with preeclampsia can show symptoms like lethargy, proteinuria (protein in the urine), and seizures, which can be life-threatening for both the mother and her offspring.