Which of the following is a sign that may indicate a broken back in mammals?

• A. Increased appetite
• B. Loss of the ability to move the tail
• C. Normal anal sphincter tone
• D. Ability to move hind legs

Answer: (B)

A spinal injury often shows up as loss of motor control in structures served by nerves below the injury; the tail is controlled by these lower spinal nerves, so an injury to the back commonly leads to the tail becoming immobile. That direct loss of tail movement is a strong indicator of a broken back.

In contrast, increased appetite isn’t linked to spinal trauma, normal anal sphincter tone doesn’t fit with spinal disruption (which can affect autonomic control and tone), and the ability to move the hind legs suggests those motor pathways are still intact, arguing against a severe back injury.