Signs of Kidney Failure in Dogs

When a dog’s kidneys are not working well, the body can no longer balance fluids, filter waste, or keep key minerals in a safe range. Kidney problems can progress quietly, so by the time symptoms are obvious, your pup may already be feeling pretty crummy. The good news is that early support and veterinary care can make a real difference in comfort and quality of life.

Quick note: This article is educational and not a substitute for veterinary diagnosis or treatment. If you are worried, call your veterinarian.

Below are the most common signs of kidney trouble in dogs, what to do right away, and how to support your dog at home while you work with your vet.

Kidney terms

People often say “kidney failure” to describe any serious kidney issue, but it can mean different things. Most cases fall into one of these categories:

• Acute kidney injury (AKI): A sudden decline in kidney function, sometimes due to toxins (antifreeze/ethylene glycol, certain medications), severe dehydration, infections (including leptospirosis), or obstruction.
• Chronic kidney disease (CKD): A gradual loss of kidney function over months or years, more common in older dogs.

CKD is often managed long-term. AKI can be a crisis that needs urgent treatment. They can also overlap, like a dog with CKD who suddenly worsens due to dehydration or a toxin.

Common signs

Many kidney-related symptoms look like “general illness.” Pay extra attention if you notice a cluster of changes, or if symptoms are worsening over days to weeks.

Drinking and peeing changes

• Drinking more water than usual (polydipsia)
• Urinating more or needing more frequent potty breaks (polyuria)
• Accidents in the house in a previously house-trained dog
• Very little urine or straining to urinate, which can be an emergency

Appetite and weight changes

• Decreased appetite or suddenly “picky” eating
• Weight loss and muscle loss
• Nausea signs like lip smacking, drooling, or turning away from food

Vomiting, diarrhea, dehydration

• Vomiting (especially recurring)
• Diarrhea or soft stool
• Dehydration (dry or tacky gums, sunken eyes, reduced skin elasticity)

Energy and behavior changes

• Lethargy and reduced interest in walks or play
• Weakness or seeming “wobbly”
• Depression or hiding more than usual

Breath and mouth changes

• Bad breath that smells like ammonia or chemicals
• Mouth ulcers or sore, inflamed gums

Urgent warning signs

• Not eating for a full day, especially if your dog is also vomiting, losing weight, acting painful, or already has CKD (puppies and small dogs may need help sooner)
• Repeated vomiting or vomiting with weakness
• Collapse, severe weakness, or disorientation
• Very pale gums (possible anemia or poor circulation)
• Seizures
• No urine output or painful straining

Call the vet now

If you suspect kidney trouble, it is safer to call your vet promptly. Early treatment can prevent a mild issue from becoming a crisis.

Seek emergency care immediately if your dog:

• Cannot keep water down
• Has little to no urine, cries when trying to pee, or seems blocked
• May have eaten a toxin
• Is extremely lethargic, collapsed, confused, or having seizures

Toxins to mention right away: antifreeze (ethylene glycol), human pain relievers like ibuprofen or naproxen, some other medications (including certain antibiotics), and grapes and raisins. Xylitol is also a true emergency toxin for dogs, even though it is better known for causing low blood sugar and liver injury rather than kidney damage specifically.

Bring any packaging you can and write down timing, amounts, and symptoms if possible. If you cannot reach a clinic quickly, you can also contact ASPCA Animal Poison Control or Pet Poison Helpline for guidance (consult fees may apply).

Diagnosis

Veterinarians usually confirm kidney dysfunction with a combination of history, physical exam, and lab work. Common diagnostics include:

• Bloodwork: kidney markers like creatinine and BUN, and often SDMA for earlier detection
• Urinalysis: urine concentration (specific gravity), protein levels, and signs of infection
• Blood pressure: high blood pressure is common in CKD and can worsen damage
• Urine culture: to check for bacterial infection when indicated
• Imaging: X-rays or ultrasound to evaluate kidney size, stones, tumors, or obstruction

If your dog is diagnosed with chronic kidney disease, your vet may discuss staging (often using IRIS guidelines) to guide treatment and monitoring.

What treatment can look like

Kidney care depends on the cause and how advanced the problem is. Here is the big picture of what your vet may recommend:

• AKI: often hospitalization, IV fluids, anti-nausea medications, and treatment for the underlying cause (toxin exposure, infection, obstruction). Some dogs need intensive monitoring and repeat lab checks.
• CKD: long-term management may include a kidney-support diet, hydration support, phosphate control, blood pressure management, and medications for nausea and appetite. The goal is to help your dog feel good and keep values stable for as long as possible.

Prognosis varies a lot based on cause and stage, so your vet is the best guide for what to expect in your dog’s specific case.

At-home care

Once your veterinarian has a plan in place, supportive home care can improve comfort and help stabilize labs. Think of this as a team approach. You, your vet, and your dog are on the same side.

Hydration support

• Keep fresh water available in multiple spots.
• Ask your vet if wet food is appropriate to boost moisture intake.
• For some dogs, veterinarians prescribe subcutaneous fluids at home.

Nutrition goals

Kidney-support diets aim to reduce the workload on the kidneys while keeping your dog nourished. In general, veterinary kidney diets focus on:

• Controlled phosphorus
• Appropriate protein quality and amount (not “no protein,” but the right kind and balance)
• Balanced omega-3 fats (often from fish oil)
• Carefully balanced minerals and added B vitamins as needed

If you want to feed homemade, please do not guess. Whole foods can be wonderful, but kidney disease is one of those conditions where the mineral balance matters a lot. Ask your veterinarian for a referral to a board-certified veterinary nutritionist, or use a recipe formulated specifically for your dog’s stage of kidney disease.

Medications and supplements (vet-guided only)

• Phosphate binders (if blood phosphorus is high)
• Anti-nausea medications and appetite support
• Blood pressure medications when needed
• Antibiotics if an infection is confirmed
• Omega-3 supplements if recommended, with dosing based on weight and health status

If your dog has kidney disease, avoid giving over-the-counter pain medications unless your veterinarian specifically instructs you. Many human medications can be dangerous to kidneys.

What to track

These simple observations can help your veterinarian spot changes earlier:

• Water intake: note if your dog is refilling the bowl more often
• Urination: more frequent trips, larger volume, accidents, or straining
• Appetite: what was offered vs. what was eaten
• Weight: weekly weigh-ins can be very helpful
• Vomiting episodes: timing, frequency, and what it looked like
• Energy level: normal, slightly off, or clearly not themselves

If your dog has diagnosed CKD, ask your vet how often to recheck bloodwork, urine testing, and blood pressure. Monitoring schedules vary by stage and stability, but regular rechecks are a key part of staying ahead of flare-ups.

If something feels off, trust that instinct and call your veterinary team. It is always better to check early than to wait.

Risk factors

Not every case has a single clear cause, but these are common contributors and risk factors vets look for:

• Age: CKD is more common in senior dogs
• Prior AKI episode: kidneys may be more vulnerable afterward
• Chronic or recurrent infections (including kidney infections)
• High blood pressure (can worsen kidney damage)
• Congenital or inherited issues in some dogs
• Dental disease: may contribute to systemic inflammation, so keeping teeth and gums healthy supports overall health

Prevention

Not all kidney disease is preventable, but these steps can reduce risk and support earlier detection:

• Annual wellness exams, and twice-yearly for seniors
• Routine bloodwork and urinalysis as recommended for age and risk
• Good dental care to reduce chronic inflammation and infection
• Keep toxins secured (antifreeze, grapes and raisins, human medications)
• Prompt treatment of vomiting, diarrhea, or dehydration, especially in older dogs

A caring note

Kidney disease can feel scary, but you are not powerless. With early veterinary care, the right nutrition plan, and supportive home routines, many dogs live comfortably for months to years after diagnosis. If you are seeing any of the signs above, schedule an appointment and bring your notes. Your observations are valuable, and they can help your vet tailor care to your dog’s exact needs.