USG reflects renal concentrating ability. Normal dogs and cats can concentrate to 1.030–1.050 or higher when dehydrated. Use Urine Strip AI to analyze urine dipstick results with AI-assisted interpretation.
Isosthenuria (1.008–1.012) indicates the kidneys are neither concentrating nor diluting—consistent with loss of renal function, though can occur with medullary washout.
Hyposthenuria (below 1.008) indicates active dilution—diabetes insipidus, psychogenic polydipsia, or iatrogenic fluid overload. Always interpret USG with hydration status and BUN/creatinine. A dehydrated animal with isosthenuria has renal dysfunction.
pH: Alkaline urine (above 7.5) may indicate UTI with urease-producing bacteria, or sample delay. Acidic urine favors calcium oxalate crystal formation.
Protein: Trace to 1+ can be normal. Persistent 2+ or greater suggests glomerular disease, hemorrhage, or inflammation. Confirm with UPC.
Glucose: Any positive result is abnormal—diabetes mellitus most common. Renal threshold in dogs ~180 mg/dL.
Ketones: Positive in diabetic ketoacidosis, starvation, or metabolic disorders. Acetoacetate is detected; beta-hydroxybutyrate is not.
Bilirubin: Small amounts normal in concentrated dog urine. Positive in cats is always abnormal.
Blood: Can indicate hematuria or hemoglobinuria. Sediment examination distinguishes.
Centrifuge 5 mL urine at 1000–2000 rpm for 5 minutes. Resuspend and examine under 10× and 40×. Report cells and casts per high-power field (HPF).
RBCs: More than 5/HPF suggests hemorrhage—UTI, urolithiasis, neoplasia, coagulopathy.
WBCs: More than 5/HPF suggests inflammation—UTI, cystitis, prostatitis.
Casts: Hyaline casts may be normal. Granular, waxy, or cellular casts indicate renal tubular damage.
Bacteria: Correlate with culture. Contamination from collection or delay can cause false positives.
| Crystal | pH | Shape | Significance |
|---|---|---|---|
| Struvite | Alkaline | Coffin lid, prism | UTI, urolithiasis; can dissolve with diet |
| Calcium oxalate | Acid | Envelope, dumbbell | Hypercalcemia, ethylene glycol; do not dissolve |
| Ammonium biurate | Variable | Thorn apple | Portosystemic shunt, liver disease |
| Cystine | Acid | Hexagonal | Breed-related (e.g., bulldogs); genetic |
Crystals in urine do not always indicate urolithiasis—supersaturation can cause crystalluria without stone formation. However, recurrent struvite or calcium oxalate crystalluria in at-risk patients warrants management.
Discuss urinalysis findings and next diagnostic steps with the Internal Medicine Specialist. Always culture urine when UTI is suspected—empiric antibiotics without culture contribute to resistance.
Abnormal urinalysis findings require interpretation in context. Proteinuria, glucosuria, or persistent bacteriuria warrant further investigation. Crystalluria in a patient with urinary signs may indicate urolithiasis.
- Isosthenuria (1.008–1.012) = renal dysfunction when dehydrated.
- Hyposthenuria (<1.008) = active dilution (DI, psychogenic polydipsia).
- Struvite: alkaline, coffin lid—can dissolve with diet.
- Calcium oxalate: acid, envelope—do not dissolve; ethylene glycol.
- Always culture when UTI suspected—avoid empiric antibiotics.