What common symptom is shared by aspergillosis, frounce, tapeworm, roundworms, or lead poisoning?

Weight loss is a common symptom shared by aspergillosis, frounce, tapeworm, roundworms, and lead poisoning. These conditions can lead to a decreased ability to absorb nutrients or may disrupt normal feeding behavior, both of which can result in weight loss. For instance, aspergillosis is a fungal infection that can affect the respiratory system and weaken a bird's overall health, leading to weight loss. Similarly, parasitic infections such as tapeworms and roundworms consume nutrients that would otherwise support the host's body, leading to significant weight loss over time. Lead poisoning causes damage to vital organs and can also alter feeding habits, further contributing to this symptom.

While poor appetite, flecks of red in the mutes, and extreme thirst can be associated with some of these conditions, they do not universally apply to all the listed ailments in the same way that weight loss does. Thus, the most accurate choice reflecting a symptom common to all these conditions is weight loss.