ACVIM Required Reading - Renal and Urinary Tract Disease

Question 1

Can serum creatinine concentration at presentation be used to predict survival in horses with renal failure?

Answer 1

• Yes.
• Non-survivors (mean = 9.4mg/dL) had higher creatinine concentrations than survivors (mean = 6.1mg/dL).

Ref: J. Vet. Intern. Med. 2011; 25(6):1426–1430.

Question 2

Are serum calcium concentrations different in horses with acute renal failure and chronic renal failure?

Answer 2

• Mean serum calcium concentration was significantly higher in horses with CRF than ARF.
• Cases of ARF were more likely to be normocalcaemic or hypocalcaemic, whereas CRF cases were more likely to be normocalcaemic or hypercalcaemic.

Ref: J. Vet. Intern. Med. 2011; 25(6):1426–1430.

Question 3

What is the complication rate associated with renal biopsies in horses? What complications are seen?

Answer 3

• Study of 151 biopsies in horses 48h-30y old.
• 11.3% had complications (9% minor, 2.3% major).
• 0.7% mortality rate (fatal haemorrhage).
• Haemorrhage (7/17).
• Colic (6/17).
• Macrohaematuria (4/17)
• Microhaematuria (2/17).
• Pyrexia (2/17).
• Abortion (1/17 - no evidence linking directly to biopsy).
• Death (1/17).

Ref: J. Vet. Intern. Med. 2011; 25(3):532-539.

Question 4

List risk factors for complications when performing renal biopsies in horses.

Answer 4

• Biopsy of left kidney.
• Diagnosis of neoplasia.
• Low urine specific gravity.
• NB No association with complications was found for age, sex, breed, institution, presenting complaint, other initial clinicopathologic data, biopsy instrument, needle size, or use of ultrasonographic guidance.

Ref: J. Vet. Intern. Med. 2011; 25(3):532-539.

Question 5

What is the likelihood of obtaining a diagnostic sample following renal biopsy in horses? What is the agreement of diagnosis from biopsy with that at necropsy?

Answer 5

• Biopsy specimens yielded sufficient tissue for a histopathologic diagnosis in most cases (94%).
• Dx had only fair (72%) agreement with PM findings.

Ref: J. Vet. Intern. Med. 2011; 25(3):532-539.

Question 6

Is renal replacement therapy safe and efficacious in adult horses?

Answer 6

• Study performed with horses in stocks for 6h, connected via a commercial renal replacement machine with blood flow rate 250 mL/min; dialysate rate 3,000 mL/h; prefilter replacement pump 3,000 mL/h; and postfilter replacement pump rate 2,000 mL/h. Balanced electrolyte solution was used as dialysate and replacement fluid.
• Renal replacement therapy was successfully performed in horses, resulting in a mean creatinine clearance of 0.127 mL/kg/min (68.9 mL/min) and urea reduction ratio of 24%.
• No adverse effects were detected although a significant decrease in rectal temperature was observed (P .007). A significant increase in serum phosphorus (P .001) and decrease in BUN (P .04).

Ref: J. Vet. Intern. Med. 2013; 27(2):308-316.

Question 7

Describe the risk factors for development of calcium carbonate urolithiasis in goats.

Answer 7

• The breed with the highest odds of developing calcium carbonate uroliths was Nigerian Dwarf.
• Breeds with the lowest risk of developing calcium carbonate uroliths included mixed, Anglo-Nubian or Nubian, and Toggenburg.
• Goats of African descent (Pygmy, Nigerian Dwarf, Boer) had significantly higher odds of developing calcium carbonate uroliths than did those of non-African descent.
• Goats that were > 4 yo.
• Males were approx 196 times as likely to develop calcium carbonate uroliths as were females.
• Calcium carbonate uroliths were sig more likely to be collected in Autumn, Summer and Winter than in Spring.

Ref: J Am Vet Med Assoc 2015;247(3):293–299.