Certified Wildlife Rehabilitator Practice Test 2026 - Free Wildlife Rehabilitation Practice Questions and Study Guide

In this scenario, the presence of lethargy and painful legs in the orphan opossums points towards a potential nutritional deficiency as the most likely diagnosis. Opossums, especially young ones, require a specific balance of nutrients for growth and development. If their diet is lacking in essential vitamins and minerals, particularly calcium and vitamin D, they may suffer from metabolic bone disease, which can lead to symptoms such as lethargy and pain in the limbs due to weakened bones and muscles.

While infections and parasite infestations can also cause lethargy, the specific symptom of painful legs is more closely associated with a deficiency in nutritional intake in young wildlife. Dehydration could lead to lethargy, but it typically doesn’t manifest as limb pain. Therefore, given the age of the opossums and the symptoms presented, a nutritional deficiency is the most likely cause of their condition.