The SDMA is a good test in terms of being able to identify things earlier and show indications earlier than, say, BUN or Creatinine.
But FIVE pounds...? Is he a larger yorkie in general?
With protein in urine and a 5lb gain -- I
really think you need to at least consider ruling out Cushings bc it absolutely does run in yorkies.
The very first screening test you do (which is *not* diagnostic, btw!) is the Cortisol-Creatinine Ratio Urine Test (can be positive, negative, or "intermediate"). Even if intermediate - you often still want to proceed w/ diagnostic testing if clinical symptoms of Cushings are present in the dog.
Symptoms:(from this great overview)
Some dogs with Cushing’s disease show the classic symptoms, while other show only a few vague symptoms. The classic symptoms are:
-- Polyuria/polydipsia (PU/PD)- This is excess urinating and excess drinking of water. It is one of the first signs of the disease, and usually precedes the other symptoms by a significant period of time. Several other important diseases cause these symptoms also, notably liver disease, kidney disease pyometra, and diabetes mellitus (sugar diabetes).
--Pot bellied abdomen to the point a dog might look pregnant. It is due to hepatomegaly and abdominal muscle weakness (the mechanism of which was described above in the physiology section).
-- Thin skin and usually symmetrical hair loss along the trunk. The hair might grow in lighter in color or lose its luster. It might not grow in well at all. Calcium deposits under the skin, called calcinosis cutis, occur on occasion. Secondary skin infections called pyoderma are common also. The skin might also be hyperpigmented.
-- Muscle wasting over the head, shoulders, thighs, and pelvis.
-- Polyphagia- excess appetite. This is often interpreted by clients as being healthy, since most people think of a sick pet as not eating well. In this case your pet is over-eating, which is consistent with Cushing’s.
Other occasional symptoms include: -Pruritis (itchy skin) - due to secondary bacterial, fungal, or parasitic infections of the skin
-Panting- due to affects on the lungs or the respiratory center in the brain
-Obesity
-Anorexia (poor appetite)
-Straining to urinate or blood in urine due to urinary tract infection or bladder stone
-Weakness
-Depression
-Aggression
-Lethargy
-Corneal plaques
-Irregular heat cycles in female dogs
-Testicular atrophy in males and clitoral enlargement in females
-Emesis (vomiting) due to pancreatitis
-Ataxia (incoordination), blindness, circling, and seizures due to a large pituitary tumor or spread of a malignant adrenal tumor
-Lameness due to a ruptured cruciate ligament
-Intra-abdominal bleeding near the kidneys (retroperitoneal space) resulting in anemia, weakness, and abdominal pain