Kidney Disease in Senior Dogs: Early Signs, Screening and Diet

The kidneys have enormous reserve, which is a problem: by the time an older dog shows obvious signs of chronic kidney disease (CKD), most of the working tissue is gone. Screening in the senior years finds it years earlier, when treatment changes the course.

Early signs

• Drinking more and urinating more (measure it: refilling bowls more often, bigger puddles, needing out at night)
• Weight loss and loss of muscle, coat losing shine
• Reduced appetite, picking at food
• Occasional vomiting, bad breath with a chemical smell
• Lethargy
• Later: mouth ulcers, pale gums, weakness

Screening

A senior blood panel with creatinine and SDMA, plus a urinalysis with urine specific gravity and a urine protein-to-creatinine ratio, and blood pressure. SDMA rises when roughly a third of kidney function is lost, creatinine only after about three quarters, so the two together catch disease earlier. Yearly from the senior stage; twice yearly if values are borderline. Dogs diagnosed are staged with the IRIS system, from stage 1 (early) to 4 (advanced), which sets the treatment plan.

What slows it down

Kidney diet. The single treatment with the strongest evidence. Prescription kidney diets (restricted phosphate, moderated high-quality protein, added omega-3 and alkalinizing agents) roughly doubled survival time in the landmark trial compared with a standard maintenance food. Introduced gradually and early, while the dog still eats well and can learn to like it.

Blood pressure control. High blood pressure damages the kidneys further and is common in CKD. Treated with medication and checked at each visit.

Phosphate control. Diet first, then phosphate binders if needed.

Protein in the urine. Treated with ACE inhibitors or similar drugs, which slow progression.

Hydration. Wet food, water fountains, several bowls. Subcutaneous fluids at home in later stages.

Nausea and appetite. Anti-nausea drugs and appetite stimulants keep dogs eating, which keeps them alive.

Avoid NSAIDs and other kidney-stressing drugs unless your vet specifically approves them, and never let a CKD dog go without water.

The takeaway

Kidney disease in an older dog is common, quiet and manageable when found early. Ask for SDMA and a urine test at every senior check-up, and act on a rising trend before values leave the normal range.