Hello, my name is***** and I have over 20 years of experience as a veterinarian. I am sorry to hear about Nova's increased water consumption compared to normal and positive test for protein in her urine.
A normal dog's kidneys can handle them eating high levels of protein, because they can effectively filter protein even at higher amounts, so although a 44% protein food is higher than usual, I don't believe that is the issue.
Even though her water consumption may be within normal limits for her size, if it is consistently more than usual for her without very hot weather or lots of exercise, or a change in diet from canned to dry then that tells us we may be at the beginning stages of a health issue.
The level of concern about urine protein depends upon whether she also shows signs of a urinary tract infection, as urinary tract infections artificially elevate protein levels due to red and white blood cells in the urine. If there is protein in the urine I recommend culturing it look for an infection.
If she doesn't have an infection then we need to compare the amount of protein in her urine in context of how concentrated her urine is. If her urine is highly concentrated (specific gravity of 1.045 or higher) with small amounts of protein I am less concerned. But if her urine is poorly concentrated (1.020 or less) with even small to moderate amounts of protein I start to get concerned. This may point toward poorly functioning kidneys and can be a sign of early kidney failure. That would explain her elevated urine protein levels.
A good test to run in a dog without a urinary tract infection and poorly concentrated urine is called a urine protein/creatinine ratio. I suspect that is the test your veterinarian is recommending. This compares the amount of protein in her urine to the waste product creatinine. If she is spilling a high amount of protein compared to waste products then yes we do need to be concerned and we need to control her protein spillage with drugs, such as Enalapril or Benazepril.
SDMA is a new test to help evaluate kidney function. SDMA usually increases when there is about a 40% decrease in kidney function, compared to elevations in creatinine, which doesn’t increase until there is up to 75% loss of kidney function. If this test wasn't part of the bloodwork checked on Nova it is worth discussing checking that with her veterinarian.
If she has high blood pressure that can certainly cause protein to spill into her urine so they should check her for high blood pressure as well.
It may also be advised to start her on a diet formulated for kidney failure, such as Hills k/d or Royal Canin Renal LP if kidney failure is suspected.
I will often recommend adding an omega 3 fatty acid supplement as well as a natural anti-inflammatory to help with kidney health. I recommend an omega 3 fatty acid dose based upon the EPA portion (eicosapentanoic acid) of the supplement as if we do that the rest of the supplement will be properly balanced. Give him 20mg of EPA per pound of body weight per day. For example a 50 pound dog 1000mg of EPA per day.
So to answer your primary question, without knowing what her urine specific gravity is, and whether she has high blood pressure or signs of an infection on a urine culture, I can't say how concerned you should get and what sort of follow-up should be done. Her protein levels need to be taken in context.
Please let me know if you have any further questions.