Kidney Disease in Dogs: Signs, Stages and Care

By Tailwisp Editorial TeamUpdated October 17, 20263 min read

The kidneys work quietly until much of their function is gone. Spotting early changes gives dogs more good time.

What the kidneys do

They filter waste from blood, regulate water and electrolytes, help control blood pressure and support red blood cell production. When they fail, waste products build up and the body becomes unbalanced.

Acute versus chronic

• Acute kidney injury: sudden damage from toxins, infection, dehydration, heatstroke or poor blood flow. It is an emergency, and some dogs recover with prompt treatment.
• Chronic kidney disease: gradual, progressive loss of function, common in older dogs, which can be managed but not cured.

Signs

• Increased thirst and urination. See excessive thirst and urination in dogs
• Weight loss and reduced appetite
• Vomiting and nausea
• Bad breath, sometimes with mouth ulcers
• Lethargy
• Pale gums or poor coat
• Dehydration

Causes

• Age-related decline
• Toxins: grapes and raisins, antifreeze and some medications. See dog poisoning: what to do
• Infections, such as leptospirosis. See leptospirosis in dogs
• Genetic conditions in certain breeds
• Dehydration or low blood flow
• Urinary obstructions

Diagnosis and staging

Blood tests, urinalysis and blood pressure measurement help confirm disease and assign a stage, often using IRIS staging. Imaging may look at kidney size and shape. See dog bloodwork explained.

Treatment

For acute injury: hospitalization, intravenous fluids, treatment of the cause and monitoring.

For chronic disease:

• Kidney-support diets. See diet for dogs with kidney disease
• Fluids at home, as your vet teaches
• Medication for blood pressure, protein loss, nausea, appetite or phosphorus
• Treating infections or stones
• Regular rechecks

Home care

1. Provide constant fresh water.
2. Feed the prescribed diet and make changes gradually.
3. Track appetite, weight and thirst.
4. Keep medications on schedule.
5. Report vomiting or lethargy promptly.

Appetite support

Dogs with kidney disease often feel nauseated. Anti-nausea medication, warming food and offering small, frequent meals can help. See dog not eating.

Monitoring over time

Plan rechecks every few months, or as your vet advises. Keep records of weight, blood work and blood pressure.

Common mistakes

• Restricting water
• Waiting for severe signs
• Changing diet without advice
• Giving human painkillers. See why human painkillers are dangerous for dogs

Troubleshooting

• My dog refuses the kidney diet: ask for alternatives or appetite aids.
• My dog is vomiting more: call your vet.
• My dog's thirst has increased: book a recheck.

A simple plan

1. Know the early signs.
2. Get bloodwork for seniors. See senior dog checkups.
3. Follow staging and treatment.
4. Keep up with rechecks.

Real-life examples

A senior spaniel with increased thirst is diagnosed with early CKD and thrives on diet and monitoring. A young dog that ate raisins receives intensive fluids and recovers. A shepherd with advanced disease is made more comfortable with fluids at home. Early action helps.

Quality of life

Work with your vet to balance treatment and comfort as the disease progresses.

Staging and what it means

Staging by blood tests, urine protein and blood pressure helps your vet choose treatment and predict the likely course. Ask which stage your dog is at, what the targets are for phosphorus, protein loss and blood pressure and how often to recheck. Understanding the numbers helps you notice progress or change.

Fluids, nausea and comfort

Some dogs benefit from fluids given under the skin at home. Your vet can teach the technique, and many owners find it easier than expected. Treating nausea and mouth ulcers improves appetite and comfort, so report any sign of vomiting, drooling or reluctance to eat promptly.

The takeaway

Kidney disease is serious but often manageable. Watch for increased thirst and weight loss and get bloodwork regularly.

This article is general educational information, not veterinary advice. Every dog is different. If your dog is unwell, or you are unsure about a symptom, diet change or medication, contact your veterinarian.