Equine Urinary

Question 1

How is acute renal failure diagnosed?

Answer 1

Sudden onset azotaemia and a low USG

Question 2

What are the most common origins of acute failure in adult horses?

Answer 2

Pre-renal and renal

Question 3

What are some common causes of haemodynamic renal failure?

Answer 3

Hypovolaemia
Volume redistribution in effusions
Decreased cardiac output
Altered vascular resistance - sepsis and endotoxaemia

Question 4

What is the most common cause of acute renal failure in the horse?

Answer 4

Ischaemia = acute tubular necrosis

Due to: prolonged haemodynamic changes, renal infarction, NSAID toxicity (prostaglandin inhibition)

Question 5

List nephrotoxins that lead to renal failure.

Answer 5

Antibiotics - aminoglycosides, polymyxin B, tetracyclines
Haemoglobin
Myoglobin
NSAIDs
Heavy metals

Question 6

What should you monitor when using nephrotoxic drugs?

Answer 6

Serum creatinine

Question 7

List some aminoglycosides

Answer 7

Neomycin
Gentamycin
Amikacin

Question 8

What is the most nephrotoxic aminoglycoside?

Answer 8

Neomycin

Question 9

How can you reduce the risk of nephrotoxicity?

Answer 9

Single dose once daily

Pre-treat with calcium

Question 10

How can you diagnose acute renal failure?

Answer 10

History and clinical signs
Urinalysis - proteinuria, presence of casts 
Azotaemia - high creatinine, high BUN 
* differentiate from dehydration using USG - isothenuria or dilute
Electrolyte changes 
- hypocalcaemia and hyperphosphataemia
- metabolic acidosis
- occ hyperkalaemia 
- hyponatraemia
- hypochloraemia

Question 11

How should you treat acute renal failure?

Answer 11

IVFT - improve renal perfusion and cause diuresis
0.9% NaCl or hartmanns at twice maintenance - 2x5L

Correct metabolic disturbances - eg spike fluids with potassium or bicarbonate

Induce diuresis - IV furosemide, dopamine CRI (potent renal vasodilator), DMSO

Discontinue nephrotoxic drugs and consider non nephrotoxic analgesia

Question 12

What are some non-nephrotoxic analgesics?

Answer 12

Morphine, butorphanol
Ketamine
Carprofen
Paracetamol

Question 13

How should you monitor the response to treatment in acute kidney failure?

Answer 13

Body weight
PCV / TP
Serum biochemistry
Provide nutritional support

Question 14

What are signs of over hydration / oliguria?

Answer 14

Ventral oedema, stocked up, anasarca

Question 15

What are the causes of chronic renal failure in horses?

Answer 15

Glomerulonephritis
Chronic interstitial nephritis (progression from ATN)
Renal neoplasia eg adenocarcinoma, lymphoma
Renal amyloidosis

Question 16

What are the clinical signs of chronic renal failure in horses?

Answer 16

Chronic weight loss
Lethargy
Poor hair coat 
PU/PD
Poor performance due to mild anaemia
Oral ulceration
Gastroenteritis 
Inconsistent ventral oedema

Question 17

How can you diagnose chronic kidney disease in horses?

Answer 17

Persistent isothenuria - 1.008-1.014 
Mild anaemia 
Mild hypoalbuminaemia 
Electrolyte abnormalities
- hyponatraemia
- hypochloraemia
- hypophosphataemia 
- hypercalcaemia 
- low bicarbonate 
Ultrasonography 
Endoscopy

Question 18

What is the normal sizes of the equine kidney on ultrasonography?

Answer 18

14-15cm