Renal

Question 1

How does juxtaglomerular apparatus control GFR?

Answer 1

A drop in GFR filtrate spends more time in the tubules so Na and Cl are absorbed more. The macula dense senses decreased levels and causes arteriole to open an increase blood flow. It also signals the juxtaglomerular cells to related running which is converted to angiotensin I and II, which constrict the efferent arterioles. This increases hydrostatic pressure and GFR.

Question 2

What breed is predisposed to polycyclic renal disease?

Answer 2

Persian cats
Cairn terriers
Bull terriers

Question 3

What is the pathophysiology of inherited polycystic kidney disease?

Answer 3

Autosomal dominant inheritance

Multiple parenchymal cystic areas are present at brith enlarge with maturity and may cause significant loss of renal function, depending on the number and volume of cystic change.

Genetic testing is available but it cannot predict the severity of the disease.

Question 4

What other organ may be affected with polycystic kidney disease?

Answer 4

Liver
Pancreas
Cystic changes in the biliary tree have been reported in dogs

Question 5

What is the most common malignant renal neoplasia in dogs?

Answer 5

Renal carcinoma

More common in males

Question 6

What is the most common benign renal neoplasia in dogs?

Answer 6

Renal hematoma

Question 7

What is the most common malignant renal neoplasia in cats?

Answer 7

Lymphoma

Question 8

What are some differentials for retroperitoneal hemorrhage?

Answer 8

Coagulopathy 
Trauma
Renal or adrenal tumors
Retroperitoneal foreign bodies or tumors
Vascular anomalies

Question 9

What is a common cause of retroperitoneal abscess?

Answer 9

Migrating foreign bodies (e.g. plant awns)

Question 10

What are some differentials for sub capsular fluid/inflammation?

Answer 10

Hemorrhage
Abscess
Acute renal failure
Ureteral obstruction
Toxicity (ethylene glycol toxicity)
Leptospirosis 
Renal neoplasia
FIP 

**hypoechoic sub capsular thickening mimicking sub capsular fluid has also been described with renal lymphoma. Blood flow was identified with color doppler analysis in the sub capsular region of these cats, indicating that the sonographic appearance was not due to fluid.

Question 11

What is a perineprhic pseudocyst?

Answer 11

Accumulation of a LARGE amount of encapsulated fluid around one or both kidneys in the subcapsular or extracapsular location. Subcapsular pseudocysts are more common than extracapsular one.

The entire kidney is usually found to be completely surrounded by a large amount of encapsulated, anechoic fluid on the ultrasound examination. They are not lined by epithelial cells.

Analysis of aspirated fluid is usually consistent with transudate.

The cause is unknown but have been associated with renal disease of various types.

Question 12

What is the treatment for perinephric pseudocyst?

Answer 12

Requires surgical removal of pseudocysts. Surgery is preferred so that the wall of the cyst can be removed and biopsy of the kidney performed. An omentalization procedure has also been used to facilitate drainage after pseudocysts removal.

Percutaneous drainage has met with limited success. Fluid will usually reform with time.

Question 13

What is vesiculoureteral reflux?

Answer 13

It is retrograde passage of urine from the bladder into the ureter because of an incompetent vesiculoureteral junction. It can predispose the upper urinary tract to infection.

Reflux may occur in younger dogs (< 6 months) without underlying pathology. However, in older animals it has been associated with cystitis, urethral obstructions, neurogenic bladder disease, and congenital anomalies.

Question 14

What is the cause of an acquired uereterovaginal fistula? What are the sonographic findings?

Answer 14

It can be caused from penetrating trauma or inadvertent ligation of the ureter during overiohysterectomy.

Clinical signs - urinary incontinence

Sonographic findings - dilated ureter and renal pelvis may occur from ascending infection and pyelonephritis. Sonographic diagnosis depends on compatible history, finding a dilated ureter and renal pelvis, and the identification of an abnormally located terminal ureter.

Question 15

What is a ureterocele?

Answer 15

A congenital dilation of the terminal ureter.

Sonographically it appears a smooth, thin-walled cystic structure that projects into the bladder lumen or occur within the bladder wall in the trigone region. Hydroureter and pelvic dilation may be present due to infection or obstruction.

The affected ureter may be ectopic or normal.

In some cases it may also cause urine outflow obstruction.

Question 16

What are urachal vs. acquired urniary diverticuliti?

Answer 16

A diverticulum appears as a fluid filled structured extending from the bladder lumen.

Urachal abnormalities are located in the cranioventral bladder wall or between the bladder and umbilicus, whereas acquire diverticulitis may originated at any bladder location.

The urachus forms a communication between the bladder and allantoic sac in the fetus that atrophies to a fibrous structure at birth. If the urachus remains patent after birth, the diagnosis is obvious because urine exits the umbilicus. If the combination is incomplete, a urachal diverticulum may be seen. The bladder wall is often thickened in this region. Urachal diverticula may predispose to recurrent UTI.

Question 17

How do acquired diverticulitis or fistula between the bladder and other organs form?

Answer 17

As a result of inflammation in the bladder wall or adjacent organs.

Question 18

What is a common cause of emphysematous cystitis and what bacteria are associated with it?

Answer 18

DM is a predisposing factor

Glucose fermenting bacterial, such as E. coli is most common.
Can occur with Aerobacter and Proteus infections and in a condition where the bladder wall becomes hypoxic and infection with Clostridium species occurs.

Question 19

Why does hypercalcemia result in nephrocalcinosis?

Answer 19

The renal tubules often have calcification when excessive calcium is being excreted via the kidneys.