Urinary Tract Pathology

Question 1

Developmental abnormality - Renal aplasia

Answer 1

Absence of one or both kidneys
Large functional reserve of kidneys means compatible with life
Common in Dobermans and Beagles

Question 2

Developmental abnormality - Renal dysplasia

Answer 2

Abnormal organisation of structures within the kidneys (cysts or misshaped)
Common in Golden Retrievers, Shih Tzus and Lhaspa apso)

Question 3

Developmental abnormality - Renal cysts

Answer 3

Spherical, thin-walled distentions typically filled with clear, watery fluid

Question 4

Developmental abnormality - Polycystic kidney disease

Answer 4

Cysts continue to expand with fluid, compressing adjacent tissues
Common in pigs, lambs, Persian cats and bull terriers

Question 5

Glomerular Disease - Suppurative Glomerulonephritis

Answer 5

Occurs with bacteraemia:
Actinobacillus equi - microabscesses which appear as multifocal, pinpoint, pale lesions in the renal cortex

Question 6

Glomerular Disease - Immune mediated glomerulonephritis

Answer 6

Type III hypersensitivity reaction that embolise in glomerular vessels
Caused by pyometra, pyoderma, Lymes disease, hepetatitis, strangles, strep, parasitism, neoplasia, autoimmune diseases, FIP, canine infectious hepatitis, FIV)

Increase in fibrous connective tissue and mesangial matrix.
Loss of glomerular capillaries
Glomerulus contract and shrinks

Question 7

Glomerular Disease - Glomerular Amyloidosis

Answer 7

Disrupts glomerular filtration resulting in protein losing nephropathy
Kidneys are enlarged, pale and waxy/smooth

Question 8

AKI - Acute tubular necrosis

Answer 8

Destroyed tubular cells or renal tissue from nephrotoxic or ishcaemic agents

Question 9

AKI - Toxic tubular necrosis

Answer 9

Renal tubular epithelial cells susceptible to toxic damage due to receiving 20-25% of blood volume
Nephrotoxins (regeneration possible because basement membrane not damaged) = ethylene glycol, antibiotics, NSAIDS, overgrowth of Clostridium, plants, lead, haemoglobin etc.

Question 10

AKI - Ischaemic tubular necrosis

Answer 10

Susceptible because they have a high metabolic demand and limited collateral circulation

Results from decreased blood pressure or blood volume (shock, dehydration, heart failure)

Characteristic wedge shaped area o pallor infarction surrounded by a red rim in the cortex

Question 11

AKI - Acute tubulointerstitial nephritis

Answer 11

Infectious agents ascending up the tubules into the intersititum
Lepto, adenovirus and herpesvirus cause iscehmic necrosis of renal tissue

Question 12

CKD

Answer 12

Extensive interstitial fibroplasia, lymphoplasmaytic inflammation, tubular atrophy and glomerular sclerosis
Kidneys will be irregular, nodular and pale
Soft tissue mineralization
Calcification of sub pleural connective tissue and cranial intercostal spaces

Question 13

Chronic tubulointerstitial nephritis

Answer 13

Lymphocytes and plasma in intersititum
Fibroplasia and atrophy of tubules
Kidneys will be pale, irregular and nodular
Feline infectious peritonitis (coronavirus) and Mycobacteria cause granulomatous nephritis with kidneys that have multifocal, white/grey, firm nodules

Question 14

Pyelonephritis

Answer 14

Dilated renal pelvis containing purulent materia
Commonly caused by E.coli, urethral obstruction or cysitits

Question 15

Hydronephrosis

Answer 15

Dilated renal pelvis with urine due to obstructed flow
Medullary and cortical tissue can show atrophy, fibrosis and schema

Question 16

Ischaemic papillary necrosis

Question 17

Patent urachus

Answer 17

Foetal urachus has failed to close, leaving a direct channel between the bladder apex and umbilicus
Resulting in dribbling urine, risk of rupture and uroperitioenum

Common in foals

Question 18

Acute cystitis

Answer 18

thickening (oedema and cell infiltrate) and reddening (hyperaemia) of the bladder wall
mucosal ulceration in the lamina propriety vessels = haemorrhage

Question 19

Chronic cystitis

Answer 19

Diffuse form:
entire wall is irregularly thickened due to epithelial hyperplasia

Follicular and polypoid form:
thickening is multifocal and nodular

Question 20

Enzootic haematuria

Answer 20

Cattle consuming bracken fern
Hyperaemia and haemorrhage in the urinary tract - haematuria
Epithelial hyperplasia and dysplasia