Why Is My Dog Or Cat's Blood Sodium to Potassium Ratio Abnormal ?









Ron Hines DVM PhD

To see what normal blood and urine values are, go here

For an explanation of causes of most abnormal blood and urine tests, go here

To see how tests are grouped, go here

Your Pet's Sodium:Potassium Ratio = Na:K In Your Pet’s Blood

Veterinarians ask for this test or pencil the calculations themselves when they are suspicious that your dog might have Addison’s disease (adrenal glands that can no longer produce enough cortisone). Your pet's Na:K ratio is calculated from its blood sodium level divided by its blood potassium level (We like to see that ratio between 27 and 40:1) . Because Addison’s disease can deplete your dog’s sodium and elevate its blood potassium, ratios that begin with a number lower than 27 might mean that an ACTH test for Addison’s disease is in order.


Reasons Why Your Pet's Na:K ratio might be low :

Sodium and potassium are two of your pet's blood electrolytes. Not all pets with a low sodium:potassium ratio have Addison’s disease.

Sustained diarrhea, or the inability to urinate (as in a ruptured urinary bladder) can also lower your pet's Na:K ratio.

Akita dogs can also have low ratios for reasons that are not understood.

Repeated removal of pooled abdominal or chest fluids and whipworm infections are also capable of decreasing Na:K ratios.

The same cautions I gave about laboratory-produced false reading for sodium and potassium apply to your pet’s Na:K ratio as well. The same causes I gave for low blood sodium or high blood potassium will drive down the Na:K ratio. The reverse is also true.