The density increase in urine was predicted using IBT. A simple test determined it was increased over that of normal bed rest and that head down bed rest, lowered density to near water readings, indicating that kidneys were not filtering as they should.
The following article may help you to determine which is better or worse, though, there are many variables with different medical conditions.
www.2ndchance.info/dxme-SpGravity.htm
Reasons Why Your Pet’s Urine Specific Gravity Reading Could Be High :
A normal or high urine specific gravity usually indicates that your pet’s kidneys are working well. But it can also be high if your pet has developed diabetes that has allowed sugar to leak into its urine or when the protein content of the urine is abnormally high.
Reasons Why Your Pet’s Urine Specific Gravity Reading Could Be Low :
Persistently low urine specific gravity in your dog or cat is more common, and potentially more worrisome than high specific gravity. In older pets, it is often the first sign (along with increased water consumption = polydipsia) that their kidneys are failing. Persistently low urine specific gravity is called isosthenuric urine (1.008-1.012). That urine is more or less the same concentration (osmolality) as the pet’s blood plasma and it means that the pet’s kidneys can neither concentrate nor dilute urine once it has initially formed. Those pets are usually azotemic as well.
What clinched it for me was my Father's kidneys had stopped functioning in Hospital and his urine was brown with blood and more like tar than urine. Tilting his bed reversed this problem and his kidneys functioned normally again. Despite being told his kidneys would never recover.