Pu/Pd toolkit

Question 1

BRIEF EXPLANATION OF PATHOPHYSIOLOGY OF PU/PD?

(PD = >100ml/kg/day (dog))

(PU = >50ml/kg/day)

Answer 1

Loss of functional nephrons → inability to concentrate urine → polyuria → polydipsia.

Found in CKD and less commonly in AKI.

• *Polyuria due to inability to concentrate urine. Four main mechanisms:**
  1. Lack of ADH secretion

2. Lack of response to ADH
3. Osmotic diuresis (losing more water than conserving, water is being drawn into the tubules)
4. Primary polydipsia (rare)

Question 2

BRIEF EXPLANATION OF PATHOPHYSIOLGY OF Oliguria?

Answer 2

Oliguria

(reduced urine output: <0.5 mL urine/kg/hour)

Found most commonly in AKI:

Nephrons are damaged at different sites (glomerulus, tubular cell, intercellular junction, basement membrane) depending on etiology → acute decline in glomerular filtration rate → increased urea/creatinine, decrease in urine specific gravity → uraemic signs, oliguria (sometimes anuria or polyuria), fluid and electrolyte imbalances, acidosis

Question 3

Briefly explain the pathophysiology of Straining (stranguria)?

Answer 3

Obstruction in the urinary tract which interferes with the flow of urine and causes irritation

Question 4

Briefly explain the pathophysiology of Blood in urine (haematuria)?

Answer 4

Irritation to the mucosa of the urinary tract caused by obstruction, urolithiasis or bacterial infection (cystitis)

Question 5

Briefly explain the pathophysiology of Reduced appetite or anorexia associated with PU/PD?

Answer 5

Due to uraemia = Polysystemic toxic syndrome resulting from severe azotemia due to decreased renal function. Azotemia is an increased concentration of non-protein nitrogenous compounds, eg urea and creatinine, in the blood.

Retention of waste products → toxemia (uraemia)→ catabolism of body tissues → anorexia

Can also be due to oral ulceration.

Question 7

Briefly explain the pathophysiology of oral ulcers in PU/PD?

Answer 7

Result of uraemia

Question 8

Briefly explain the pathophysiology of weight loss in PU/PD?

Answer 8

Sign of CKD

Uraemia causes a reduced appetite/anorexia, which leads to weight loss if persistent

Question 9

Briefly explain the pathophysiology of Lethargy and weakness in PU/PD?

Answer 9

Associated with uraemia

Question 10

Briefly explain the pathophysiology of Vomiting in PU/PD?

Answer 10

Associated with uraemia

Question 11

Briefly explain the pathophysiology of Incontinence (urinating in the house/in their bed at night) in PU/PD?

Answer 11

Increased volume of urine in the bladder leads to increased urgency and incontinence

Question 12

History – list specific questions you would ask the owner if you were suspicious of urinary tract disease?

Answer 12

How much is he drinking on a daily basis?

Are they urinating more/less often?

Have they started urinating in the house/in a different place to normal (cats in terms of litter trays)?

Are they obviously straining when they go to the toilet?

Noticed any blood in the urine?

What colour is the urine?

Are they licking at their genital area?

Any change in diet recently?

How is their appetite?

How are they in themselves? Lethargic/quiet?

How long have the signs been going on?

Question 13

List common differentials for URT disease in the horse?

Answer 13

Renal neoplasia

CKD/renal failure

AKI (ischaemia, CRGV, thromboembolism, trauma)

Polycystic disease

Developmental abnormality

Glomerulonephritis

Renal tubular acidosis

Uroliths

Question 14

List common differentials for URT disease in the cat?

Answer 14

• Renal neoplasia
• CKD/renal failure
• AKI (ischaemia, CRGV, thromboembolism, trauma
• Fanconi syndrome
• Polycystic disease
• Perinephric/perirenal pseudocyst
• Developmental abnormality
• Uroliths

Question 15

List common differentials for URT disease in the dog?

Answer 15

• Renal neoplasia
• CKD/renal failure
• AKI (ischaemia, CRGV, thromboembolism, trauma)
• Fanconi syndrome
• Polycystic disease
• Pyelo/hydronephritis
• Developmental abnormality
• Uroliths

Question 16

List common differentials for URT disease in the ruminant?

Answer 16

• Renal neoplasia
• AKI (ischaemia, CRGV, thromboembolism, trauma)
• Pyelo/hydronephritis
• Developmental abnormality
• Uroliths

Question 17

List common differentials for Lower urinary tract disease in the cat?

Answer 17

• FLUTD

If no abnormalities are identified consider a purely behavioral problem. However, if cat is currently asymptomatic repeat investigation when the cat is symptomatic.

Many cats which are believed to have a behavioral problem have a history of FLUTD in their past.

• Urolithiasis
• Cystitis
• Neoplasia
• Behavioral abnormalities resulting in urine marking Indoor marking.
• Trauma.
• Coagulopathy.

Question 18

List common differentials for Lower urinary tract disease in all other species?

Answer 18

Lower Urinary Tract Disease Ddx

• Cystitis
• Bladder diverticulum
• Urolithiasis
• Neoplasia: bladder, ureter
• Lower urinary tract obstruction
• Diabetes mellitus
• Hyperadrenocorticism
• Chemotherapeutic agents: (cyclophosphamide causes sterile hemorrhagic cystitis).
• Urethral dysfunction, bladder dysfunction.

Question 19

List differentials for Hematuria?

Answer 19

Trauma: bladder rupture

Neoplasia: Ureter, Bladder, Urethra

Clotting disorders

Renal hemorrhage (idiopathic, renal neoplasia, trauma).

Prostatic disorders: benign hyperplasia and hypertrophy, abscessation ,cyst, neoplasia.

Question 20

List differentials for tenesmus?

Answer 20

Colon disease

(Peri-)anal or rectal disease: Perianal fistula, Anal sac impaction, Anal sacculitis, constipation or obstipation.

Prostate disease: (See above)