Equine Urinary Disease

Question 1

What are common presenting complaints?

Answer 1

Lethargy, depression, anorexia, weakness
Weight loss
Abnormal micturition
Abnormal urine appearance
Decreased performance
Recurrent colic
Abnormal behavior

Question 2

Why would a chronic renal patient be anemic?

Answer 2

Decreased production of erythropoietin
Shorter lifespan of RBCs in horses with CRF

Question 3

What do BUN and creatinine tell you?

Answer 3

Most commonly used indices of renal function
Requires ~75% of nephrons to be nonfunctional before values are increased
Once elevated, can interpret a doubling of BUN and creatinine as a 50% decline in remaining renal function

Question 4

What is azotemia?

Answer 4

Laboratory abnormality
Elevation in both BUN and creatinine

Question 5

What is the most common form of azotemia?

Answer 5

Pre-renal
Associated with hypovolemia and renal hypoperfusion
Concentrating ability is maintained

Question 6

What occurs in renal azotemia?

Answer 6

Urine concentrating ability is lost in the face of dehydration or hypovolemia

Question 7

What occurs in post-renal azotemia?

Answer 7

Obstruction or disruption of post-renal urinary tract
Progressive abdominal distention

Question 8

What are the characteristic changes in biochemistry values with a neonate with uroperitoneum?

Answer 8

BUN and creatinine - increase
Na - decrease
K - increase
Cl - decrease
Lactate - increase
HCO3 - decrease

Question 9

Water deprivation for 24 hours should produce a USG greater than what?

Answer 9

1.045

Question 10

What is the USG of suckling foals?

Answer 10

Typically hyposthenuric

Question 11

How would you determine a foal is dehydrated or hypovolemic based on USG?

Answer 11

> 1.030

Question 12

What pH is a horses urine normally?

Answer 12

Alkaline
7-9
Can cause false positives on protein dipstick

Question 13

Does normal equine urine contain glucose?

Answer 13

No

Question 14

What is the estimated renal threshold for equine kidneys?

Answer 14

~170 mg/dl

Question 15

What are some causes of glucosuria in the horse?

Answer 15

Sedation with a2 agonists
Stress
Exercise
Exogenous corticosteroids
Sepsis
PPID
Dextrose containing fluids

Question 16

Is it normal to see crystals in equine urine?

Answer 16

Yes!

Question 17

Where is the left kidney?

Answer 17

Deep to the spleen

Question 18

Describe what you would see on ultrasound with acute renal failure.

Answer 18

Kidneys often appear normal
Normal or enlarged size
Peri-renal edema
Loss of distinction of the corticomedullary junction

Question 19

Describe what you would see on ultrasound with chronic renal failure.

Answer 19

Decreased kidney size
Irregular shape and margins
Increased echogenicity (renal fibrosis)
Cystic or mineralized areas of parenchyma

Question 20

What is acute renal failure?

Answer 20

Clinical syndrome associated with sudden reduction in GFR

Question 21

What aminoglycoside is most nephrotoxic?

Answer 21

Neomycin

Question 22

How do you help diminish aminoglycoside induced renal toxicity?

Answer 22

Once daily dosing rather than multiple doses

Question 23

What are the clinical signs of acute renal failure?

Answer 23

Anorexia, lethargy, depression
Oliguria, anuria
Tachycardia
Conjunctival edema
Limb or truncal edema