Characterizing and treating chronic kidney disease in dogs and cats
Linda E. Luther, DVM, DACVIM (SAIM)
Small Animal Track
November 2012
The overall goals of chronic kidney disease therapy are to:
 Minimize clinical signs
 Slow disease progression
 Preserve/enhance Body Condition Score (BCS)
CATER THERAPY TO THE CHARACTERISTICS OF EACH INDIVIDUAL
CASE.
Note: Don’t forget to rule out prerenal azotemia first!
(Urine specific gravity > 1.030 in dogs, > 1.035-1.040 in cats)
How can you tell if it is chronic vs. acute kidney disease?
 History (> 3 months)
 Hematocrit
 BCS
 Kidney size
Why call it chronic kidney disease (CKD) vs. chronic renal failure (CRF)?
 Condition is progressive
 At time of diagnosis, quality life remains
 Encourages therapy
 Don’t ignore poor long term prognosis though
IRIS (International Renal Interest Society) CKD Staging (www.iris-kidney.com)
 Diagnosis, prognosis and therapy recommendations
 CKD Stages 1-4
 Staging is based on at least two creatinine levels when the animal is fasted and well
hydrated.
 Proteinuria and blood pressure are also substaged.
If creatinine is > 2 mg/dL (Stage 2-4 cats, Stage 3-4 dogs): A renal diet is recommended.
 Prevents/delays onset of uremia and premature death, decreases proteinuria, improves
quality of life
 Protein, phosphorus, sodium and calcium are restricted.
 Omega-3 fatty acids, antioxidants, B vitamins, soluble fiber and potassium (feline diets)
are added.
 Increased caloric density (higher in fat, watch if a dog has a history of pancreatitis)
 Neutral effect on acid-base balance
Decreased body condition score and inappetance
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
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Uremic gastritis/oral ulcers may be factors.
Decreased caloric intake can also contribute to anemia, azotemia.
Treat with famotidine, mirtazapine.
Hydration status
 Maintain hydration
 **Encourage water consumption
 SQ or IV fluids can be used, but the fluids available may contain too much sodium
Proteinuria
 Localize (renal vs. post renal)
o If urine sediment is active, post renal proteinuria exists.
o If urine sediment is inactive, run urine protein/creatinine ratio to quantify renal
proteinuria.
 Persistent/significant?
o Document 3x at 2-week intervals if not azotemic.
o Rule out infectious disease, recent vaccination, etc…
 Therapy
o Renal diet
o ACE inhibitors (enalapril vs. benazepril)
o Spirinolactone?
o Omega-3 fatty acids
o Low-dose aspirin (0.5 mg/kg q 24 h in dogs only)
o Immunosuppression?
Hypertension (BP > 160 mmHg)
 Amlodipine in cats (0.625 mg/cat q 24 h)
 ACE inhibitor in dogs to start. Add amlodipine if necessary.
Hypokalemia
 Especially in cats! “Pathophysiologic justification” vs. evidence
 Oral potassium gluconate (2 mEq/4.5 kg body weight BID with meals)
 Adequate potassium (KCl) should be added to IV and SQ fluids (see table below):
(From DiBartola SP and De Morais HA , 2012)
Potassium level (mEq/L)
KCl (mEq/L)
< 2.0
2.1-2.5
2.6-3.0
3.1-3.5
3.6-5.0
80
60
40
28
20
Max infusion (mL/kg/hr)
(< 0.5 mEq/kg/hr)
6
8
12
18
25
Hyperphosphatemia
 First treat with a phosphorus restricted diet.
 If still hyperphosphatemic, then treat with phosphorus binders (given with food)
o Aluminum hydroxide (compounded if needed) (30-45 mg/kg BID)
o Ca salts
 Epakitin™: Chitosan and CaCarbonate
Hyperparathyroidism (HPTH)
 Underlying calcitriol deficit results in HPTH. Parathyroid hormone (PTH) is a uremic
toxin (contributes to symptoms).
 Hyperphosphatemia is a marker/predictor of HPTH. HPTH may also exist w/normal
phosphorus levels. Total and ionized calcium can be normal, increased or decreased.
 First control hyperphosphatemia/keep phosphorus in low normal range with
diet/phosphorus binders (see above).
 Then consider calcitriol. Calcitriol therapy should decrease PTH.
o Dose approx.. 2-3 ng/kg/day or pulse therapy (9 ng/kg q 3.5 d or Wed. PM/Sun
AM). Give on an empty stomach.
o Do not use if hypercalcemic. Do not use calcium containing phosphorus binders
concurrently.
o Monitor by measuring PTH, ionized calcium and phosphorus.
o Dogs: Increased survival shown w/calcitriol tx if IRIS stages 3 & 4.
o Cats: Unproven, clinical observations positive, “pathophysiologic justification”.
Anemia
 Mechanisms: Decreased erythropoietin, blood loss, decreased red blood cell lifespan
due to uremia
 Treat when hematocrit < 20%
o Epoetin (Procrit®, Epogen®)
 Cats and dogs: 100 IU/kg SQ 3x/wk then 50-100 IU/kg 2x/wk
 25-30% of cats develop anti-EPO antibodies
o Darbepoetin (Aranesp®)
 Cats: 1 ug/kg once weekly
 Longer half life, so less frequent administration
 One study, 56% of cats responded
 Less immunogenic?
o Side effects: Hypertension, EPO antibodies, seizures
o Concurrent iron dextran injections (10 mg/kg IM q. 3-4 weeks for cats) or
ferrous sulfate (100-300 mg/dog/day PO) is recommended.
o Goal hematocrit cat 25-30%; dog 30-35%
Positive culture, pyuria
 Nonconcentrated urine may not show pyuria or bacturia in sediment.
 One study, 29% CKD w/occult urinary tract infections, so run cultures (w/MICs).
Metabolic acidosis
 If bicarbonate < 15 mmol/L (more of a problem during a uremic crisis), treat with:
o Renal diet first
o Sodium bicarbonate or potassium citrate can be added to food.
Ureteral calculi
 Weigh benefits vs. risks of surgical vs. medical management
 Medical therapy can include fluids, diuretics, amitriptyline, pain medications, control of
CaOx calculi
Chronic kidney disease (CKD): Problem-based therapeutic plans
Parameter
Urine specific gravity
Chronic vs. acute
IRIS CKD stage dogs
IRIS CKD stage cats
Plan
If ≥ 1.030 in dogs, ≥1.035-1.040 in cats, then elevated creatinine =
prerenal azotemia.
Chronic if > 3 month history, decreased BCS, hematocrit or kidney size,
and/or increased parathyroid gland size
1: Cr<1.4 mg/dL; 2: Cr 1.4-2 mg/dL; 3: Cr 2-5 mg/dL; 4: Cr>5 mg/dL
1: Cr<1.6 mg/dL; 2: Cr 1.6-2.8 mg/dL; 3: Cr 2.8-5 mg/dL; 4: Cr>5
mg/dL
Creatinine > 2 mg/dL
Renal diet
Decreased
BCS/Appetite
Famotidine, mirtazapine, feeding tube
Hydration status
Encourage water consumption, give SQ or IV fluids to normalize
Proteinuria
If dipstick positive and quiet urine sediment, do urine
protein/creatinine ratio
Urine Pr/cr ratio
If > 0.5 in dogs, > 0.4 in cats, treat with diet change, ACE inhibitor,
spirinolactone, omega-3 FAs and in dogs, aspirin. Consider
immunosuppression in dogs. If 0.2-0.5 in dogs, 0.2-0.4 in cats, monitor
Systemic hypertension
(BP > 160 mmHg)
Amlodipine in cats, ACE inhibitor +/- amlodipine in dogs
Hypokalemia
Oral potassium gluconate supplement and/or supplement fluids w/KCl
Hyperphosphatemia
Hyperparathyroidism
Anemia
Positive urine culture,
pyuria
Leptospirosis
titer/PCR
Metabolic acidosis
(HCO3 < 15 mmol/L)
Ureteral calculi
First, phosphorus restricted diet, then phosphorus binders w/meals:
AlOH, calcium carbonate, Epikatin (Ca carbonate+chitosan)
First, control hyperphosphatemia (see above), then rx calcitriol
If hct < 20%, consider epoetin or darbepoetin and iron supplementation.
Goal hct of 25-30% cats; 30-35% dogs
Antibiotics
Antibiotics if positive or suspected
Renal diet, sodium bicarbonate, potassium citrate
Medical or surgical therapy
Therapy of CKD references
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Disclaimer: Please verify all drug dosages before administering.