Notes Oct 13 UGA CE – Renal Injury

Selena Lane

Isosthenuria is 1.007 – 1.015

When you see azotemia just know that 66% of nephrons are dysfunctional. Not necessarily irreparably.

UNTIL there’s that much damage, lab tests for kidney are undetectable. NOTE: I wonder  if old dogs should eat K/D or a kidney sparing diet “any way” say, from ten on? Ajax?

AKI stands for Acute Kidney Injury

Low blood pressure (hypotension) during anesthesia can injure kidneys. Damage them ischemically.

NSAIDS can injure the kidneys.


  • ADR with GI signs, melena. Appetite off. 5% dehydrated. “Seems” sudden. 
  • Labs:   Elevated white cell count. Slight left shift. <= High WBC in renal failure: Think Lepto at least for a minute.
  • Labs: BUN 129, CREAT 8.0 K+ high.
  • Labs UA blood, USPG 1.012 (iso)

Renal imaging Ultrasound is a top shelf but useful diagnostic

Lepto tests can be false-positive in immunized dogs. So RISING TITERS are the “thing”

PRACTICE NOTE:  All renal cases:  Lepto snap –> If ambiguous – chase it down because people are at risk.

Lepto tests available: MAT/PCR/Snap

Management: They measure urine output. Normal is 1-2ml/kg/hour. They catheterize or weigh pads. Not sure what they can do with that information other than say “The dog is oliguric, anuric, polyuric. NOTE: If he’s not letting off his fluids due to oliguric renal disease, he might get “fluid overload”

  • (tears from the nose)
  • (They can even get edema, even in the face!)
  • Difficult to reverse at that point.
  • Weigh the pet to see suspicious short term gains – she said that several times.
  • Furosemide increases renal flows, perfusion. But can result in dehydration.

If a pet is dehydrated with a USPG of 1.007 – 1.015 the kidneys are impaired.

I get this feeling that clinicians just want to know, know, know everything about a case. It’s nice to know everything that’s going on and micromanage the disease process but so much of this is irrelevant to survival and a lot of it provides useless information except: To know.

Practicality note: Synthetic colloid fluid support is neither helpful nor detrimental to AKI patients. But in people can set up sepsis.

She likes Mannitol – up to the possibility that it might result in untoward fluid retention. (Injection only?) Increases flow, flushes tubules, reduces tubular swelling.

Dopamine, Fenoldopam. My takeaway is that it’s not as good as Furosemide.

Lepto AKI? Consider Diltiazem. They recover faster.

Then the owner goes crazy and wants the pet alive no matter the impact on the pet:   Peritoneal dialysis, Hemodialysis, constant transfusion.

Lepto kidneys have a decent prognosis. 60% of dog AKI’s die. And of the survivors, 60% end up managed long term for CKD

Cats do a little better.




Dr Erik Johnson is a Marietta, Georgia Veterinarian with a practice in small animal medicine. He graduated from University of Georgia with his Doctorate in 1991. Dr Johnson is the author of several texts on Koi and Pond Fish Health and Disease as well as numerous articles on dog and cat health topics.