Final answer:
For a 10-day old dairy calf with white diarrhea, dehydration, and weakness, IV fluids with added sodium bicarbonate is the treatment of choice to quickly address dehydration and electrolyte imbalances, including metabolic acidosis due to loss of bicarbonate.
Step-by-step explanation:
The appropriate treatment for a 10-day old commercial dairy calf with these symptoms would be IV fluids with added sodium bicarbonate. The symptoms described, including diarrhea that is white in color along with dehydration, hypovolemia, and weakness, indicate a likely case of electrolyte loss due to the excretion of fluids high in sodium (Na) and bicarbonate (HCO3). Given the calf's inability to stand and the hypovolemic state, oral fluids might not be sufficient or fast-acting enough to reverse the dehydration.
Based on the provided information and assuming no other abnormalities found on physical examination, the best choice would be IV fluids to promptly address the dehydration and electrolyte imbalance. The addition of sodium bicarbonate to the IV fluids will help correct the metabolic acidosis that often accompanies dehydration in calves with diarrhea.