a 12-year old male budgerigar is evaluated because of a two-week history of progressive difficulty gripping with the right foot. The client reports that during the past three days, the bird has stopped using the foot entirely but he still flies around the house daily. On physical examination, mild coelomic distention is palpated. The bird is standing on his perch using the left leg only. All toes of the right food are pointing downward with no gripping capability. Which of the following is the most likely cause of the paralysis?
a. Chronic heavy metal toxicity
b. Previous trauma
c. Renal neoplasm
d. Right-sided intervertebral disk disease
e. Severe arthritis