Times change and my website needed to change too. To see the 2020 update of this page click this link
To see what normal blood and urine values are, go here
For an explanation of causes of most abnormal blood and urine tests, go here
To see how tests are grouped, go here
When your dog or cat 's kidneys loose that selective ability, they have been severely damaged in one way or another. So the earlier your veterinarian can detect that this is occurring, the more likely he/she will be to stop or slow the process.
The microalbumin test is the most accurate early warning system that veterinarians currently have (check 2016 SDMA link at top right too). For many years, veterinarians and physicians relied simple dipstick methods to detect the level of protein (including albumin) in urine to warn them of the problem and, perhaps, followed that up with an SSA test. But many health issues other than kidney damage can account for elevated urine total protein readings obtained in that manner. Those tests were also not able to detect the very small amounts of protein present early in disease (kidney glomerular scaring, glomerulosclerosis). This was particularly true in cats. There are other options (to the MA test) for detecting the beginnings of protein leakage in early kidney disease. One is the Idexx Urine P:C ratio test .
Your vet is still likely to begin a health check with a simple urine dipstick; but more likely now to follow up with a microprotein (or another "early marker") assay. That is because chronic kidney disease is the most common problem veterinarians see in older dogs and cats.
The MA test is also one of the best monitoring test to follow the progress of kidney disease once you know that your pet has a chronic kidney problem (CKD).
Any degree (amount) of damage to your pet’s kidney filtering apparatus (glomeruli) or the tubes that convey processed urine to the bladder ("tubulo-interstial disease") or generalized kidney inflammation and disorders will elevate your pet's MA test results.
An elevated MA test can also be a tip-off to problems that are not centered in your pet’s kidneys but that are affecting its kidneys. Problems such as heartworm disease, chronic inflammatory, autoimmune diseases, feline leukemia, feline immunodeficiency virus, Cushing's disease and just about any other health problem that causes general debility fit into that group.
Urinary tract infections can cause MA tests to be high as can blood present in the urine for any reason (visible to the eye [gross hematuria, frank blood] or unseen (=occult blood +). (ref)
1) All pets that had a positive or suspicious urine dipstick or SSA tests for protein, unexplained low urine specific gravity unexplained increases in thirst or urination. 2) All pets that have confirmed kidney disease - to judge the rate of progress of the disease. 3) Breeds of cats and dogs or pets whose close furry family members suffered from kidney disease at a young age (particularly if you intend to breed them). 4) Pets with elevated blood pressure and cats with confirmed hyperthyroidism.
2) I hesitate to recommend the MA test as a part of yearly geriatric profile screening tests if your pet has no other evidence of ill health or kidney damage. That is because so many elderly pets (and their human owners) will have positive results. Just be sure your older pets eat a sensible diet, maintain a sensible weight and, most importantly, consume as much fluids in their diets as possible.
Late in the process of kidney damage, when little blood filtering ability remains, MA levels can actually decrease because most of the kidney sieves (glomeruli) have already shut down. In those cases, less albumin ends up in the urine. But at that stage, your pet would already be toxic (uremic, azotemic) and its blood urea and creatinine levels would be quite high. So there would be no mistaking the cause.
You can read how Antech Diagnostics suggests your veterinarian proceeds when a microalbuminuria result comes back high here.
Tests and examinations for possible alternative explanations for the high MA other than kidney damage - such as severe skin and ear infections, gum disease, heartworms. Inflammatory bowel disease (IBD) , Lyme disease and other Tick-transmitted diseases.