Final answer:
A 25-pound dog might filter several liters of fluid per day through the glomeruli but will likely excrete under 1000 mL of urine, as most of the filtrate is reabsorbed.
Step-by-step explanation:
The glomerular filtration rate (GFR) provides an estimate of the amount of fluid filtered by the kidneys' glomeruli each day. In humans, the GFR is about 180 L/day in men and 150 L/day in women. However, due to tubular reabsorption, a large percentage of this filtrate is returned to the bloodstream, leaving only about 1-2 liters of the initial filtrate to be excreted as urine. Given this information, and minus specific data for dogs, we could extrapolate that a 25-pound dog may produce a similar but scaled-down volume of glomerular filtrate, possibly several liters per day, but ultimately excrete much less as urine, likely under 1000 mL (1 liter) considering the average human urine production ranges from 600 mL to 2500 mL per day.