Hannah Zulueta The Acid Your Dog’s Kidneys Can No Longer Clear
Metabolic acidosis in dogs with kidney disease: where to find it on the bloodwork, what it takes from the body, and what potassium citrate is for.
It shows up on bloodwork as CO2, TCO2, or bicarbonate, and standard panels usually don’t measure it. When that number drops, a kidney dog tends to eat less and lose muscle faster. Here is how to read it and what can be done.
Is metabolic acidosis in dogs with kidney disease treatable?
Yes. It shows up as a low TCO2 or bicarbonate, and IRIS recommends treatment when that number falls below 18 mmol/L. Left alone, the extra acid pulls minerals from bone, breaks down muscle, and dulls appetite.
- Food: moderate protein and low phosphorus lower the daily acid load.
- Medicine: your vet may add potassium citrate or sodium bicarbonate.
- Your dog’s potassium level decides which of the two fits.
Why can’t I find TCO2 on my dog’s bloodwork?
Because standard bloodwork panels usually don’t include it. It tends to show up for dogs with advanced kidney disease whose vet knows to order it, or who have a nephrologist on their care team. When it is measured, it appears as a line called CO2, TCO2 (total carbon dioxide), bicarbonate, or HCO3. All four measure the body’s main acid buffer. Lower means more acid.
- Check your dog’s results for any of those four names.
- If none appears, ask your vet to add it to the next panel. Some labs offer it as an add-on.
- Or ask about a blood gas test. Many clinics can run one in the building, and it reports bicarbonate within minutes.
If your dog has advanced kidney disease, this number is worth asking for by name.
Reference ranges differ a little between labs. Your vet reads the number against your lab’s range and your dog’s trend.
What is metabolic acidosis?
Think of the kidney as the drain under the kitchen sink. Every meal leaves a little acid behind, the way every dish leaves a little grease in the pipe. A healthy kidney flushes that acid out in the urine and holds on to bicarbonate, the body’s own baking soda.
As kidney function drops, the drain slows. The kidney makes less ammonia, which is the main carrier it uses to send acid out (Polzin, 2011). Acid backs up into the blood, and bicarbonate gets used up neutralizing it. That is metabolic acidosis.
What would I notice at home?
No single sign points to acidosis. The signs overlap with kidney disease in general, which is why the bloodwork line is so useful.
- A dog who approaches the bowl, then walks away.
- Weight holding steady while the spine and hips feel sharper under your hand. That is muscle going.
- Less interest in walks, and more time lying down.
- Nausea signs: lip licking, drooling, grass eating.
What does potassium citrate actually do?
Citrate is the compound that makes a lemon taste sour. Once it is absorbed, the liver converts it into bicarbonate. So potassium citrate delivers buffer to the blood without being a harsh alkali in the stomach.
It also delivers potassium. That second job decides whether it fits your dog. Your vet may use sodium bicarbonate instead, which carries sodium in place of potassium. Choose a situation below to see how that choice tends to go.
It corrects the acid and tops up potassium in the same dose. Low potassium adds its own muscle weakness and appetite loss, so a dog with both problems benefits twice.
High potassium is common in dogs on benazepril or telmisartan. Here your vet is more likely to reach for sodium bicarbonate, or to lean on diet first.
High potassium has other causes too. Addison’s disease can look like kidney disease on bloodwork, so if the reason isn’t clear, ask your vet whether Addison’s has been ruled out.
In a dog with high blood pressure, that extra sodium has a cost. If potassium allows, potassium citrate avoids it. Your vet weighs the two against your dog’s numbers.
Moderate protein and low phosphorus lower the daily acid load. Your vet may recheck on the diet before adding a supplement.
Don’t add baking soda or potassium citrate on your own. Too much alkali overshoots the other way, and potassium citrate can push potassium dangerously high. Dosing belongs to your vet.
Can food lower the acid load?
Yes. The acid in a dog’s diet comes mostly from two places. Sulfur-containing amino acids in animal protein break down into sulfuric acid. Phosphorus leaves phosphoric acid. The same two levers that protect the kidney also lower the acid it has to clear.
- Feed moderate, high-quality protein. Enough to hold muscle, without surplus. Extra protein adds extra acid. How much protein a kidney dog needs.
- Keep phosphorus low. Less phosphorus in means less phosphoric acid out. Low-phosphorus foods for a kidney dog.
- Include vegetables if potassium allows. Vegetables leave an alkaline residue. In people with kidney disease, adding fruits and vegetables improved acidosis about as well as sodium bicarbonate (Goraya et al., 2013).
- Ask whether your recipe is formulated with acid balance in mind. Prescription renal diets are built to be alkalinizing (Elliott, 2006). A homemade recipe needs the same attention.
Most of the alkalinizing power in vegetables comes from their potassium. In a dog whose potassium runs high, vegetables can’t do this job safely. For that dog, protein and phosphorus become the main food levers, and your vet covers the rest.
How does TCM see metabolic acidosis in dogs?
The picture is heavy and turbid. A dog who feels sluggish, nauseated, and uninterested in food. Breath with a sour or ammonia edge. In TCM terms, this is turbid Dampness: fluid and waste the body has failed to transform and move out.
Two organ systems sit underneath it. The Kidney provides the warmth that moves water, like a pilot light under a pot. The Spleen transforms food into usable energy, like a cook turning raw ingredients into a meal. When both weaken, residue collects.
In the bowl, that means warm, cooked, easily digested food that asks little of the Spleen. Pearl barley is one of my steady choices here. It drains Dampness gently, and it sits comfortably in a low-phosphorus recipe.
What else do owners ask about metabolic acidosis?
Can I give my dog baking soda for kidney disease?
I strongly recommend that you talk to your primary care veterinarian so they can guide you through this. Baking soda is sodium bicarbonate, and vets do use it for acidosis. The dose depends on your dog’s TCO2, weight, and blood pressure, and overshooting causes its own problems.
What is a normal bicarbonate level for a dog with kidney disease?
IRIS guidelines aim for 18 to 24 mmol/L in dogs with kidney disease, measured as bicarbonate or TCO2. Standard panels usually leave it out, so you may need to ask for it. Below 18, IRIS recommends treatment. Lab ranges vary slightly, so your vet reads the number against your lab and your dog’s trend.
Is potassium citrate safe for dogs with kidney disease?
For the right dog, under a vet’s dosing, yes. It corrects acid and adds potassium, which helps a dog with low potassium. For a dog with high potassium, often from benazepril or telmisartan, it can push potassium to a dangerous level.
Does a lower protein diet help metabolic acidosis in dogs?
Moderating protein helps, because animal protein’s sulfur amino acids become acid. Cutting protein too far backfires. Acidosis already breaks down muscle, and a protein-starved dog loses muscle faster. The goal is enough high-quality protein, without surplus.
What are the signs of metabolic acidosis in dogs?
At home, the signs overlap with kidney disease in general: poor appetite, nausea, low energy, and muscle loss along the spine and hips. The clearest signal is a TCO2 or bicarbonate below the target range, which you may need to ask your vet to measure.
Where do I look next if my dog has stopped eating?
Acidosis is one reason a kidney dog stops eating. The Kidney Disease hub covers the recipe, and the Gut Health hub covers nausea and the digestive side of a dog who has gone off food.
Want a recipe built to lower the acid load?
I build TCM Dietetics kidney recipes with protein, phosphorus, and potassium set to your dog’s own bloodwork, including TCO2 when it has been measured.
References
Elliott, D. A. (2006). Nutritional management of chronic renal disease in dogs and cats. Veterinary Clinics of North America: Small Animal Practice, 36(6), 1377-1384.
Goraya, N., Simoni, J., Jo, C. H., & Wesson, D. E. (2013). A comparison of treating metabolic acidosis in CKD stage 4 hypertensive kidney disease with fruits and vegetables or sodium bicarbonate. Clinical Journal of the American Society of Nephrology, 8(3), 371-381.
International Renal Interest Society. (2023). IRIS treatment recommendations for CKD in dogs. IRIS Kidney.
Mitch, W. E., Medina, R., Grieber, S., May, R. C., England, B. K., Price, S. R., Bailey, J. L., & Goldberg, A. L. (1994). Metabolic acidosis stimulates muscle protein degradation by activating the adenosine triphosphate-dependent pathway involving ubiquitin and proteasomes. Journal of Clinical Investigation, 93(5), 2127-2133.
Polzin, D. J. (2011). Chronic kidney disease in small animals. Veterinary Clinics of North America: Small Animal Practice, 41(1), 15-30.
