Test 1- Urinary Flashcards
1
Q
Where is the kidney located?
A
Kidneys have retroperitoneal location
2
Q
How is the renal parenchymais divided?
A
The renal parenchymais divided into: cortex, medulla and pelvis (papilla).
- Renalpapilla→renal calices → renal pelvis → ureters
- There are anatomic variations among animal species.
3
Q
A
Multipyramidal with external lobation. Normal bovine kidney
4
Q
A
Normal feline kidney
5
Q
A
Multipyramidal without external lobation. Normal porcine kidney
6
Q
A
Bovine kidney. Normal peri‐renal fat
7
Q
Structure and Function of the Kidney
A
STRUCTURE AND FUNCTION
STRUCTURE
- Gomerulus=Filtering mechanisms
- Tubules=selective reabsorption
FUNCTIONS
- 1=regulationoffluidand electrolyte content
- 2=endocrinesuchas renin and erythropoietin
8
Q
RENAL APLASIA
A
Defined as absence of development of a kidney, can be unilateral (incidental finding), or bilateral (fatal)
Failure of development of one or both kidneys.
- Itisararedevelopmental abnormality.
- Seeninswine,dog (familial tendency in Doberman pinscher and beagle dogs), and cattle.
9
Q
Renal hypoplasia
A
Renalhypoplasiaisa quantitative defect caused by reduced mass of metanephric blastema.
- Hypoplastic kidneys appear smaller than normal.
- Renal hypoplasiahas been described in pigs, foals, dogs (Cocker spaniels), and chickens.
- Differentialdiagnoses includes renal dysplasia (see next), and differentiation requires histological examination.
10
Q
Renal Dysplasia
A
Renal Dysplasia is a rare condition very difficult to diagnose grossly.
• Bydefinition,renal dysplasia is an abnormal and asynchronous differentiation (disorganized development) of renal tissues.
Severe bilateral dysplasia may lead to renal failure.
• CasesofRenaldysplasia are difficult to differentiate from other conditions, such as chronic renal disease with diffuse fibrosis.
11
Q
A
Renal dysplasia
12
Q
A
Renal hypoplasia
13
Q
Causes of renal dysplasia:
A
Congenital infections: Feline Panleukopenia, Canine herpesvirus, Bovine virus diarrhea
- Autosomaldominantin Suffolk sheep
- HypovitaminosisAinpigs
Renal dysplasia in a calf.
• Intrauterineureteral obstruction in pigs and calves
14
Q
A
Renal dysplasia in a calf.
15
Q
RENAL CYSTS
A
Renalcysts area common congenital renal malformation found in pigs, calves and to a lesser extent, in other species.
• Cystsofvariablesizeare typically filled with fluid and lined by flat or cuboidal epithelium.
16
Q
A
Renal cysts. Porcine
17
Q
A
Renal cysts can be uniorbilateral,singleormultiple. • Significance:Often it is just an incidental finding.
18
Q
Polycystic kidneys
A
Grossly,kidneyscontain numerous variably‐sized cysts, in both cortex and medulla.
- Oncutsurfaceseverely affected kidneys have a “honeycomb“ appearance.
- Cystsarefilledwith colorless fluid.
19
Q
A
Polycystic kidneys
Polycystic kidney in a Persian cat. Cut surface.
20
Q
CAUSES OF POLYCYSTIC KIDNEYS
A
Congenital polycystic kidneys may be inherited as an autosomal dominant condition in pigs and lambs.
• It also occurs as an inherited condition in: – Cairn terrier dogs (in conjunction with cystic
biliary disease)
– Bull terriers
– Collie dogs
– Nubian goats
– Persian cats
21
Q
CONSEQUENCES OF RENAL CYSTS
A
CONSEQUENCES OF RENAL CYSTS
1) Cysts may grow slowly or remain static.
2) Cysts may increase in size and/or number, causing compressive atrophy.
22
Q
A
Acquired (non developmental) cysts may develop from obstructed tubules in chronic renal disease
See below: cut surface and close up of chronic renal disease in a dog
ddx for polycystic kidney dx
23
Q
Ectopic Kidneys
A
- Definition: Normal kidneys in abnormal locations.
- Often unilateral.
- Described in dogs and pigs.
- Ectopic kidneys are predisposing factors for ureter obstruction and development of hydronephrosis.
24
Q
A
Ectopic Kidneys
25
Horseshoe kidney
Congenital malformation that results from a fusion of the cranial or caudal poles of the kidneys.
26
Fused kidneys. Bovine.
27
Horseshoe kidney in a cat. Incidental finding at necropsy.
28
AUTOLYSIS
Autolysis is a common post‐mortem finding.
• Kidneysaresoft,friable
29
What is this post-mortem change?
Autolysis
30
Autolysed bovine kidney. Renal infarct is still detectable.
31
PSEUDOMELANOSIS
32
Pseudomelanosis in a kidney
Pigment is staining the surface of the kidney, as demonstrated on the image depicting the cut surface .
33
Hemoglobin
* Gross features: Dark red to black kidneys.
* Consequence of severe intravascular hemolysis and hemoglobinuria. Examples:
* Leptospirosis
* Bacillary hemoglobinuria • Babesiosis
•Chronic copper poisoning, etc.
34
Hemoglobin
35
Hemoglobinuria secondary to copper poisoning in a sheep.
36
Hemoglobinuria secondary to copper poisoning
37
Hemoglobinuria in a dog (Cut surface) and sheep (histology).
38
Myoglobin
* Gross findings: dark red to black kidneys and dark red urine.
* Mechanism: occurs when high levels of myoglobin are filtered into tubules (myoglobinuria).
* Examples:
Source: Knottenbelt and Pascoe, 2003
* Rhabdomyolysis in capture myopathy in wild animals
* Equine paralytic myoglobinuria.
39
Myoglobinuria in a horse.
40
LIPOFUCSINOSIS
Incidental finding in old cattle.
• Grossly, kidneys are dark brown to black.
41
Lipofucsinosis in a bovine
42
Lipofucsinosis in kidney and heart. Bovine tissues
Descriptions:
1) The kidney is normal in size, diffusely dark brown to black.
2) This is the cut surface of the left ventricle and atrium in a bovine heart. The cardiac parenchyma is uniformly dark brown.
43
BILE PIGMENT
In obstructive jaundice or severe liver disease, the kidneys excrete conjugated bilirubin resulting in choluria.
• •
Grossly,the kidneys are yellow‐green.
Evidence of icterus/jaundice is seen in other tissues (mucous membranes, connective tissue).
44
Bile pigment in the renal cortex in a dog with autoimmune hemolytic anemia.
45
Hyperemia and congestion
Bright or dark red kidneys.
• Hyperemia can be physiologic.
Hyperemia and congestion
•Hypostatic congestion is common as a result of prolonged prostration and circulatory failure.
46
Hyperemia and congestion
* Brightordarkred kidneys.
* Hyperemia canbe physiologic.
* Hypostaticcongestionis commonasaresultof prolongedprostration andcirculatoryfailure.
47
Hemorrhages
Hemorrhages are commonly seen in kidneys as a result of vasculitis or vascular necrosis.
• Hemorrhages could be petechial or ecchymotic.
**• If the renal capsule is not removed, renal hemorrhages can be easily overlooked.**
48
Petechiae(sometimes called turkey egg) in the cortical surface of a pig’s kidney.\*
49
Renal Hemorrhage- what does it affect and how does it look pathologically?
Petechial or ecchymotic
* Glomeruli are preferentially affected.
* Speckled appearance.
* Numerous causes:
Examples:
* Coagulopathies • Viral infections • Septicemia
* Toxins
50
Cortical hemorrhages. **Herpes virus** infection in a puppy
THIS IS VERY TYPICAL- NAVLE QUESTION
51
Causes of renal petechia
Extensive vascular injury or platelet consumption leading to disseminated intravascular coagulation (DIC).
• Acquired or congenital clotting defects (Sweet clover‐ coumarin poisoning, vitamin K deficiency, Hemophilia A and B)
52
Petechiae in the cortical surface. Bovine kidney(external lobulation).
white areas- neoplasic process that is interferring with cogulation
53
Causes of renal petechia and ecchymosis
• Viremia:
– Hog cholera leading to
endothelial damage
– African Swine fever leading to platelet destruction
– Canine herpes virus in neonatal puppies.
* Bacteremia: such as Erysipelas, Streptococcal infections, salmonellosis in pigs.
* If septicemia is suspected, different tissues such as lung, kidney and liver should be sent for bacteriological examination.
* Toxins: oak toxicity, endotoxins and enterotoxins.
54
Herpes virus
55
Bacteremia in the kidneys
petechia on the cut surface
histo section- lots of hemmaroage
56
Renal torsion in a deer.
57
Renal torsion in a deer (next to a normal kidney)
one on the right- ishemia- complete cut off of the blood supply
58
Renal Infarcts
Typically _triangular_ (wedge) in shape with the apex pointing towards the medulla.
• Renal infarcts are associated with thrombosis of renal vessels (usually the interlobular artery).
59
The size of the infarct depends on the size of affected vessels.
60
In acute cases, infarcts appear red due to s hemorrhage
pale areas of discoloration the body will think of as non-self
61
Renal infarct in a dog. Capsular and cut surface
62
What is a common cause of renal infarcts?
Valvular endocarditis (left side) is a common cause of renal infarcts
Thrombosis
63
Chronic Renal Infarcts
Prolonged ischemia leads to infarction/ coagulative necrosis.
• The affected area will heal by fibrosis and scar tissue
64
Healed renal infarcts in a cat.
Fibrosis causes retraction of the parenchyma and characteristic depressions on the renal cortex.
65
Which of these is a chronic and which is an acute infarct?
Chronic is on the right
66
Renal infarcts are most commonly seen in:
* Cattle and pigs with vegetative valvular endocarditis of the left heart.
* Cats with left atrial thrombosis associated with cardiomyopathy.
* Dogs with renal amyloidosis due to loss (through the urine) of plasma anticoagulants such as antithrombin III.
* Endotoxin‐mediated thrombosis due to Gram‐ negative sepsis or endotoxic shock (example: dogs with suppurative prostatitis).
67
Amyloidosis in a cat(remember cats have a lot of vascularness on the surface)
pale, diffuse change
68
AMYLOIDOSIS
Definition: heterogenous group of diseases due to deposition of amyloid in tissues.
* Kidney is one of the most important targets of this condition.
* Glomerular amyloidosis is a protein‐losing nephropathy.
* Deposition of glomerular amyloid impairs its function with resulting marked proteinuria.
69
TYPES OF AMYLOIDOSIS
_Primary amyloidosis:_
very rare in domestic animals.
due to deposition of amyloid AL,derived from Ig light
chains produced by abnormal plasma cells.
_Secondary (reactive) amyloidosis:_
most common form in domestic animals.
deposition of amyloid AA that originates from serumα‐
globulin
• associated with chronic antigenic stimulation e.g.chronic inflammation, infection, neoplasia.
70
Staining fresh kidneys with _iodine_ solution reveals many solid black dots which correspond to glomeruli filled with amyloid protein.
71
Kidneys with amyloidosis are enlarged, pale, and have a finely granular surface.
72
RENAL AMYLODOSIS‐ GROSS APPEARANCE
Kidneys are pale, have rounded edges. The cortical surface could be smooth and pale or slightly granular. Cut surface is pale, waxy.
73
Canine kidney. Glomerular and medullary amyloidosis.
74
RENAL AMYLOIDOSIS: Microscopic Appearance
* Deposition of pink amorphous material in glomeruli (most species) or in medullary interstitium (cats and cattle).
* Amyloid(pink homogeneous relatively acellular material) is deposited in the **_mesangial matrix_** and along the adjacent basement membrane.
* Special stains such as **_Congo red_** (polarizedlight) and Thyoflavine‐T (Fluorescence) are used to microscopically confirm amyloidosis.
75
GLOMERULAR AMYLOIDOSIS‐ HISTOLOGIC AND ULTRASTRUCTURAL APPEARANCE
76
Glomerular amyloidosis: diagnosis is confirmed with
Glomerular amyloidosis: diagnosis is confirmed with congo red stain
77
FAMILIAL RENAL AMYLOIDOSIS
* Familial renal amyloidosis occurs in Abyssinian cats and Chinese Shar Pei dogs, and it is characterized by medullary deposits of amyloid, with fibrosis and papillary necrosis.
* Amyloidosis can lead to thrombosis of pulmonary arteries or renal veins due to hypercoagulable state caused by:
– stimulation of production of acute‐phase proteins such as fibrinogen
– simultaneously losing (because of increased glomerular permeability) low‐molecular weight anticoagulants, such as antithrombin III.
78
Renal necrosis and nephrosis(the necrosis of the tubular epithelium)
Papillary necrosis, cut surface. Canine kidney- DIABETES
79
Bilateral Renal _Cortical Necrosis_
* Bilateral RenalCortical Necrosis is an acute and severe ischemia of the _renal cortex due to vasospasm of cortical vessels._
* It is an intriguing lesion that has traditionally been associated with endotoxemia.
80
Bilateral Renal Cortical Necrosis
81
Renal cortical necrosis
82
Renal Medullary (Papillary) Necrosis
83
Renal Medullary (Papillary) Necrosis
- The mechanisms are controversial.
- Caused by a localized ischemia of the renal medulla.
cortex is extremley pale; there is a ring that separates the healthy from the unhealthy kidney
84
CAUSES OF MEDULLARY NECROSIS
Amyloidosisi n cats
Pyelonephritis
Diabetes mellitus
Urinary obstruction
Use of anti- inflammatory and analgesic drugs such as phenylbutazone,phenacetin,aspirin.
85
Medullary Necrosis
86
Papillary necrosis in a horse due to NSAIDs toxicity
Greenish areas from vaso-constriction
87
Papillary necrosis in a foal NSAID toxicity
88
ACUTE TUBULAR NECROSIS (NEPHROSIS)
Acute necrosis of tubular cells is the primary process of nephrosis.
Renal tubular epithelium (especially proximal tubules) is metabolically very active,thus highly susceptible to ischemia or to toxic damage
Grossly, acute tubular nephrosis is difficult to diagnose.
The kidneys are swollen, the capsular surface is pale and moist, and bulges on cut surface.
89
ACUTE TUBULAR NECROSIS (NEPHROSIS)
## Footnote
Oak toxicity causing tubular necrosis.
90
Oxalate nephrosis, pig. Cut surface
91
DDx for pale kidneys
* Amyloidosis- Congo Red
* Acute Nephrosis-Tubular problem
* Glomerulonephritis- inflammation in the glomeruli and kidney
• Lymphosarcoma-
92
Oxalate nephrosis. Porcine kidney.
93
Lymphosarcoma- Rabbit
94
Diffuse glomerulonephritis Canine
95
Nephrosis Cougar
96
NEPHROSIS: histological appearance
• Most cases of nephrosis are acute to peracute with minimal to absent inflammatory cell infiltration.
• Cases of chronic
nephrosis are characterized by fibrosis,tubular loss, architectural disorganization,regeneration and limited inflammatory response.
Histologically, acute tubular nephrosis is characterized by swelling of the tubular epithelium.
The cytoplasm may be vacuolated and the nucleus may be pyknotic,karyolytic or karyorrhectic.
Thetubulesmaybe hypocellular,areoften dilatedandcontain necroticcellulardebris andhyalinized casts.
97
NEPHROSIS: histological appearance
98
Melamine/Cyanuric acid toxicity
99
Pathogenesis of necrosis of tubular epithelium
100
Tubular Necrosis- Outcome
If the basement membrane is intact, regeneration of the proximal convoluted tubules is seen as early as three days after the toxic insult is removed.
101
CAUSES OF NEPHROSIS
* Ingestion of exogenous substances.
* Some substances precipitate as crystals in tubules (e.g. ethylene glycol oxalate)
102
Oxalate nephrosis
cut surface will bulge
103
Oxalate nephrosis Ethylene glycol(antifreeze) toxicity
tubular necrosis
104
Causes of toxic nephrosis
Heavy metals:
– Mercury (in herbicides)
**– Lead (old paint,batteries) - MOST COMMON; gives intranucleular inclusions**
– Cadmium
– Chromium
– Copper
– Phosphorus.
• Carbon tetrachloride, chlorinated hydrocarbon insecticides.
105
lead- toxic nephrosis
106
Nephrotoxic Plants
– Pigweed (Amaranthus retroflexus)
– Oaks (Quercus sp.).
107
Pigweed(Amaranthus retroflexus) causes tubular degeneration and peri-renal edema in pigs and cattle.
Edema is around the kidney
108
Oak Poisoning
Oak poisoning occurs in cattle and horses.
• The pathogenesis of the condition is not completely known but tannins and/ or their metabolites are incriminated.It is proposed that tannic acid binds to endothelial cells causing necrosis of the epithelium.
109
Acute tubular necrosis, oak toxicity
110
What is the general routes of infection that bacteria comes into the kidney?
General routes of infection:
Hematogenous infection- descending infection- comes in via the lood
Ascending infection- from the urethra
111
Glomerulitis
if the glomeruli are the only structure that are infected
112
Glomerulonephritis
Glomerulus and parechmya involved
113
Interstitial nephritis
inflammatory process in the intersitium
114
Pyelonephritis
Ascending Infection- etioloigcal agent that goes up the urinary tract to the kidney
115
```
Glomerulitis.
Embolic Nephritis (suppurative glomerulitis)
```
Caused by bacteremia.
Pattern is multifocal suppurative glomerulitis.
Bacterial colonies are seen in glomerular and interstitial capillaries.
116
Embolic Nephritis (suppurative glomerulitis)
117
Foal kidney, cut surface–
Actinobacillus equuli
118
Progression of embolic nephritis
• Chronic renal microabscesses may develop as a result of embolic nephritis.
119
Differential Dx for embolic nephritis
You have more neutrophils going into the infected area. Eventually the capsule will be full of bacteria and the capsule then looks like this.
Embolic nephrtisis- can’t be dx grossly
ddx: when all you have is a kidney from an animal and list 3 ddx
Neoplasia
Abscesses
G- multi-focal granulamotosi
120
Glomerulonephritis
Glomerulonephritis and glomerulopathies are a heterogenous group of diseases in which the main morphologic change takes place in the glomeruli.
Glomerulonephritis are largely, but not exclusively, associated with immune mediated injury.
121
GLOMERULITIS AND GLOMERULONEPHRITIS
• Pathogenesis:
Pathogenesis: two main mechanisms, related to immune mediated processes:
– Deposition of antigen antibody (Ag/Ab) complexes- infectious disease that triggers a response
–Autoantibodies directed against the GBM (antibasement membrane disease)-body develops antibodies against the basement membrane
122
Deposition of antigen antibody (Ag/Ab)complexes
Persistent antigens in the blood result in deposition of Antigen Antibody (Ag Ab) complexes in glomerular basement membranes.
Persistent antigen can be viral, bacterial, parasitic, etc.
123
Autoantibodies directed against the glomerular basement membrane
Also known as anti basement membrane disease
– formation of auto antibodies against the GBM ---\> complement fixation--\> leukocyte infiltration.
– important in humans (e.g. acute post streptococcal glomerulonephritis), but rare in domestic animals.
124
Gross lesions of Glomerulonephritis
* Acute
* Subtle changes; kidneys appear swollen and pale.
* Chronic
* kidneys are shrunken and granular
Both have diffuse patterns!
125
Glomerulonephritis
126
Histopathology of Glomerulonephritis
Three morphologic types:
–Membranous glomerulonephritis characterized by thickening of basement membrane
–Proliferative glomerulonephritis characterized by increased cellularity-more cells than normal;
–Membrano proliferative glomerulonephritis, often leads to glomerular sclerosis-That particular glomerulus will dissapear functionally
127
Membranous glomerulonephritis
128
Proliferative vs, membranous glomerulonephritis
Membranous- thickening of basement membrane( can see on PAS stain); increased eosinophilia within the glomeruli; you use congo red to ddx from amyloid and both present with proteinuria
Proliferative- more cells than normal
129
Membrano proliferative glomerulonephritis versus glomerulosclerosis
130
What is a way to get a definative dx?
131
INTERSTITIAL(TUBULOINTERSTITIAL) NEPHRITIS
* Inflammatory infiltration in the interstitium affects tubular functions such as impaired reabsorption, concentration and/or excretion.
* Distribution
* Multifocal
* Diffuse
132
INTERSTITIAL (TUBULO INTERSTITIAL) NEPHRITIS
133
Diffuse versus multifocal interstitial nephritis
134
Diffuse Interstitial Nephritis
135
Multifocal Interstitial Nephritis
Common, usually incidental finding.
May represent a sequel of resolved bacteremia/ septicemia.
Grossly:off white foci randomly scattered throughout the renal cortex and medulla.
Common in young cattle.
It is called "white spotted kidney."
Presumed to be someresidual lesions of E.coli bacteremia in the first few weeks of life.
136
Multifocal Interstitial Nephritis
137
It is called "white spotted kidney.
Multifocal Interstitial Nephritis
138
WHITE SPOTTED KIDNEY
139
Pathogenesis of Bacterial Interstitial Nephritis
Following bacteremia the bacteria localize in the renal interstitial capillaries, migrate through the vascular endothelium, persists in the interstitial spaces, and migrate via the lateral intercellular junctions to reach the tubular lumina.
140
Causes of interstitial nephritis
• Dogs
– Leptospira interrogans serovars canicola,
icterohaemorrhagiae, and others
– Infectious canine hepatitis virus, recovery phase – Theileria parva
• Cattle:
– E. coli septicemia (white spotted kidney)
– Leptospira interrogans serovar canicola – Malignant catarrhal fever
141
Leptospira- goes in between the tubules
142
Causes of interstitial nephritis
• Sheep:
– Sheeppox
• Pigs:
– Leptospira interrogans serovar pomona
– Porcine reproductive and respiratory syndrome – PCV2 (porcine circovirus 2)
• Horses:
– Equine viral arteritis
143
Chronic interstitial nephritis
Gross apperance
Gross appearance: –kidneys shrunken,
pale, firm
–capsule firmly adhered to cortex
144
Chronic interstitial nephritis
145
PYELONEPHRITIS
Definition: Pyelonephritis is inflammation of the **renal pelvis and renal parenchyma.**
• Unlike other forms of nephritis, the lesions of pyelonephritis are not necessarily symmetrical.
It is commonly seen in pigs, cattle and dogs.
Occasionally seen in cats, horses and other domestic animals.
146
Unilateral pyelonephritis in a cat.
147
Pyelonephritis in a dog
148
Pathogenesis of pyelonephritis
Most often originates from ascending bacterial infection.
•Bacteria ascend ureters (ureteritis) invade the renal pelvis and then move through the renal tubules and reach the renal parenchyma.
149
Pyelonepritis Predisposing factors
Urinary obstruction causes stasis of urine and facilitates bacterial growth.
* Renal medulla is most susceptible to infection.
* Abnormal vesico ureteral reflux (retrograde flow of urine) normally prevented by the oblique insertion of the ureters into the bladder wall.
* Frequent sequel to cystitis (females\>males).
150
Abnormal vesico ureteral reflux
Common in puppies due to short intravesical length of the ureters and less oblique entry through the bladder wall.
Cystitis and ureteritis may interfere with ureteral peristaltic waves and predisposes to vesicoureteral reflux.
151
Pyelonephritis Gross appearance
Suppurative exudate in pelvic cavity, partial destruction of medulla,irregular discoloration of cortex.
Marked scarring and fibrosis are often seen.
Evidence of inflammation in ureter and urinary bladder.
152
Suppurative pyelonephritis in a dog
153
Severe suppurative pyelonephritis
154
Pyelonephritis Microscopic features
Acute and Chronic
Acute:Large number of neutrophils and bacteria within the lumen of renal tubules.Necrosis and exfoliation of the tubular epithelium.
• Chronic:white bands of scar tissue extending from cortex to medulla, interstitial fibrosis, loss of tubules and
finally "end stage kidney.“
155
Pyelonephritis
156
Granulomatous nephritis
• A form of _chronic_ nephritis characterized by predominance of macrophages in the inflammatory infiltrate.Etiology includes:
– Viruses such as corona virus [causing cell mediated immune response] Or FIP
– Fungal organisms
– Bacteria (such as mycobacteria i.e. TB)
– Parasite migration
157
Granulomatous nephritis (dry form) Feline infectious peritonitis
Multifocal to coalescing off-white raised nodules (interpreted as granulomas) on the cortical and cut surface.
The raised surfaces are cut off from blood circulation
158
What is the main differential dx for the dry form of FIP?
Look at age etc, but HISTOLOGY will give you the final answer.
159
Tuberculosis in a bovine
160
Granulomatous nephritis due to parasite (ascaris) migration in a dog
161
GRANULOMATOUS NEPHRITIS
Halicephalobus gingivalis migration in horses.
Saprophytic nematode – rhabditiform; previously known as (Micronema deletrix, Halicephalobus deletrix)
162
GRANULOMATOUS NEPHRITIS
Kidney from a horse
163
Dioctiophyma renale
Dioctiophyma renale
* Also called giant kidney worm.
* Occurs in mink,dogs,_other fish eating mammals._
* Large nematode (up to 1m long x 1cm in diameter).
* Nematode resides in renal pelvis.
* Can be found free in peritoneal cavity
164
Dioctiophyma renale
165
Stephanurus dentatus
Larvae migrate from intestine to liver (causing hepatitis, phlebitis, abscesses) and then across the peritoneal cavity to the peri renal fat and adjacent tissues
• Cysts often communicate with the renal pelvis
- seen in pigs, espesically backyyard pigs
166
Stephanurus dentatus (pigs)
167
Stephanurus dentatus in a pig kidney
168
Hydatid cyst. Moose kidney.
This can also affect people.
If you see a cyst in a dog, it's probably congential
In a pig, cysts can be parasitic(softer feeling) or congential.
169
Hydronephrosis in a ferret
kidney is the white bubble on the right
170
Hydronephrosis
Definition: _abnormal and permanent_ dilation of the renal pelvis and calyces with progressive atrophy of renal parenchyma.
171
Hydronephrosis in a sheep.
172
Cause of hydronephrosis
CAUSE: due to an increased pressure following partial or complete obstruction of the urine outflow.
Commonly associated with hydroureter (ureteral dilatation).
These look like water balloons
173
Unilateral hydronephrosis
174
Causes of urine outflow obstruction:
Congenital malformation of ureter, vesicoureteral junction or urethra.
Calculi (urethral uroliths in dogs and cats, ureteral or pelvis uroliths in cattle and rams).
Iatrogenic (ligation of ureter in lieu of, or with the ovarian stump).
Chronic inflammation.
Neoplasia such as urinary bladder transitional cell carcinomas or rhabdomyosarcomas located in the trigone of the urinary bladder.
Torsion of ureters or bladder.
175
Pyelonephritis (notice exudate) and hydronephrosis.
176
urolith- green thing on the kidney on the top
177
178
Hydronephrosis pathogenesis
Hydronephrosis can be unilateral or bilateral.
Initially, urine filtrate diffuses to the renal interstitium where it is absorbed by lymphatic vessels.
With time, increased pressure shuts down blood vessels causing papillary necrosis and finally atrophy of renal parenchyma (Pressure ischemia atrophy)
179
normal is on the right
abnormal kidney has no parchemya left
180
UROLITHIASIS
* Urolithiasis is the process of formation of solid or semisolid concretions (calculi) anywhere in the urinary collecting system.
* Calculi are known as uroliths.
* Uroliths are composed of a wide variety of minerals, often mixed with protein material.
181
Multiple smooth calculi are seen within a distended urinary bladder. Canine.
182
UROLITHIASIS- predisposing factors
* Increased urinary concentration of the stones’ constituents (supersaturation).
* Low urine volume (due to dehydration, low water consumption).
* Urine pH (e.g., cystine stones form at low pH)
Urinary tract infections (due to the formation of an organic matrix and pH increment).
* Diets high in phosphate in sheep.
* High levels of silica of native pastures grazed by cattle.
183
UROLITHIASIS
184
Uroliths vary in size, shape, consistency
Feline kidney- multifaceted uroliths
185
UROLITHIASIS BY STRUVITES
* Struvites (magnesium, ammonium, phosphate): most common type in dogs, linked to urinary bladder infection.
* Struvite calculi are seen in feedlot cattle feeding on high grain rations.
* Formation of calculi of struvite also occurs as a result of bacterial infection of the bladder.
186
UROLITHIASIS
Urethral obstruction is common in males.
Clinical signs: dysuria, stranguria, pollakiuria and hematuria.
187
UROLITHIASIS
188
UROLITHIASIS Possible consequences
* None, urolith passed in the urine
* Hydronephrosis if urolith is lodged in ureter
* Chronic cystitis, or bladder distension and rupture if urolith is lodged in urethra
* Acute hemorrhagic urethritis
189
UROLITHIASIS
190
Ruptured bladder (“waterbelly”) due to urethral obstruction
191
Familial Renal Diseases
* Most commonly seen in dogs compared to other species.
* Origin: may be the result of abnormal structure or abnormal
function.
– Abnormal structure:
Examples:
* Familial glomerulopathies in Samoyed and Doberman Pinshers
* Familial renal fibrosis in Norwegian Elkhounds
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Familial Renal Disease
Abnormal function
* Biochemical defects in renal tubules.
* Kidneys may appear grossly and microscopically normal Examples:
– Fanconi Syndrome in Basenji dogs
– Primary renal glucosuria in Norwegian Elkhound
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Renal response to injury
Tubular regeneration.
Healing by fibrosis if basement membrane is damaged.
Nephroscleros is if fibrosis is severe.
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Urinary system defense mechanisms
Barrier system
Glomerular mesangial cells (part of monocyte macrophage system)
General immune response
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Renal response to injury
• Degeneration
* Necrosis
* Hyperplasia
* Hypertrophy
* Atrophy
* inflammation
* Regeneration
* Fibrosis
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Tubular degeneration versus normal
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Renal fibrosis and nephrosclerosis are common sequelae to chronic inflammation.
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End stage kidneyis a term often used to describekidneys that are severely affected by chronic inflammation and fibrosis.
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End-Stage Kidney
Severe chronic inflammation and fibrosis efface the normal architecture.
It is not possible to identify the primary insult.
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End-Stage Kidneys
Kidneys are pale, shrunken, and firm
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Causes of CRF in dogs
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Causes of CRF in a cat
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Causes of CRF in LA
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Chronic renal disease Canine. Cut surfaces.
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Renal disease versus renal failure.
•Renal disease is any deviation from normal
renal structure or function.
* Renal failure is the inability of the kidney to maintain normal function; renal failure requires a loss of at least 70-75% of renal function.
* The kidney has poor functional and structural correlation.
* Renal failure requires a loss of at least 70% of kidney function.
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Chronic renal disease, Feline
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RENALFAILURE
Glomerular function tends to be disrupted by diseases that alter glomerular structural arrangements such as damage to basement membrane, endothelium, epithelium or mesangium.
Tubular function tends to be disrupted by metabolic insults to the tubular cells (e.g. hypoxia or toxins).
Renal filtration allows elimination of many metabolic waste products. Two of these substances are urea and creatinine.
Urea and creatinine have particular significance since their concentrations in plasma are clinically used to detect a renal malfunction.
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Biomarkers of renal function
* Ureais produced in the liver from nitrogenous byproducts of the protein metabolism (ammonia).
* Creatinineis the normal byproduct of phosphocreatine,a substance involved in the contraction of muscle fibers.
* Blood urea (BUN) and creatinine are filtered and excreted in the urine at a relatively regular rate.
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Renal disease versus renal failure
•Renal disease is any deviation from normal
renal structure or function.
•Renal failure is the inability of the kidney to maintain normal function; renal failure requires a loss of at least 75% of renal function.
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AZOTEMIA VERSUS UREMIA
* Azotemia is an abnormal elevation of urea and creatinine in the blood without clinical manifestations of renal disease (azotemia is, therefore, a biochemical abnormality mostly due to decreased GFR).
* Uremia is a clinical syndrome of toxemia due to intravascular accumulation of endogenous toxic waste substances such as urea, creatinine,uric acid, guanidine, phenolic acid, high molecular weight alcohols plus other metabolites.
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Clinical signs of Uremia
* Vomiting
* Dehydration or anasarca
* Polydypsia, anuria, oliguria,poliuria
* Ammoniacal breath
* Malaise due to “uremic toxins”
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NON RENAL LESIONS OF UREMIA
NON RENAL LESIONS OF UREMIA
* Uremic stomatitis / glossitis
* Hemorrhagic ulcerative gastritis and colitis
* Endocarditis /mucoarteritis
* Tissue mineralization
* Pulmonary edem
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Uremic Stomatitis /Glossitis
- Occurs in cats and dogs due to fibrinoid arteriolar necrosis and bacterial production of ammonia.
- Oral bacteria transform urea into ammonia (NH3) which irritates the oral epithelium and causes ulceration of the mucosa.
- Ulcerative and necrotizing stomatitis is characterized by a brown,foul smelling mucoid material adhered to the eroded and ulcerated lingual and oral mucosa.
- Thus, clinical exam will reveal halitosis (urine breath).
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Uremic Stomatitis /Glossitis
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Uremic Stomatitis /Glossitis
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Hemorrhagic ulcerative gastritis
Occurs as a result of arteriolar necrosis with
(a) mucosal infarction and (b) mineralization of the gastric glands and submucosal blood vessels.
The ulcerated mucosa may get secondary bacterial invasion.
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Hemorrhagic ulcerative gastritis
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Uremic gastritis/ colitis
• Uremic gastritis is seen in dogs and cats, whereas the colon is affected in horses and cattle.
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Uremic gastritis/ colitis
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Mucoarteritis/ endocarditis.
Thisisanon-inflammatory condition due to deposition of glycosaminoglycans with subsequent fibrinoid degeneration of the subendocardial connective tissue.
Intheheart,uremic mucoarteritis is most common in the left atria and proximal aorta.
Grossly,itconsistsofopaque, light yellow roughened endocardial plaques.
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Mucoarteritis/ endocarditis.
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Dystrophic and Metastatic Calcification.
Deposition of mineral in the walls of the:
– alveolar septa,
– pulmonary arterioles
– Pericardium
– soft tissues
– parietal pleura in the cranial intercostal spaces (“pleural frosting”)
It may be associated to deposition of calcium secondary to cell injury or hypercalcemia, or hyperphosphatemia.
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Dystrophic and Metastatic Calcification
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Pulmonary edema
Pulmonary edema results from damage to the air blood barrier and plasma fluid leaks into the alveoli.
• Pulmonary edema is often the cause of death in uremic animals.
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Pulmonary edema
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Uremic Pneumopathy
* Gross appearance: Lungs fail to collapse, have rounded edges, would be heavy and moist at cut surfaces.
* Histologic appearance: eosinophilic material (edema) within alveoli, basophilic material (mineralization) may be present in alveolar walls.
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NON RENAL LESIONS OF UREMIA
Uremic stomatitis /glossitis
* Hemorrhagic ulcerative gastritis and colitis
* Endocarditis/mucoarteritis
* Tissue mineralization
* Pulmonary edema
* Secondary hyperparathyroidism
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Secondary renal hyperparathyroidism
One of the many functions of the kidney is to excrete phosphorus.
Abnormal renal function results in excessive retention of phosphorus (hyperphosphatemia)
In order to maintain homeostasis,after retention of phosphorus the body responds by increasing calcium.
Thus, parathyroid glands are activated to compensate and promote reabsorption of calcium from bone.
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Secondary renal hyperparathyroidism
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Thyroid hyperplasia.
secondary renal hyperparathyroidism
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Parathyroid gland hyperplasia (renal hyperparathyroidism)
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CYSTITIS
•Natural antibacterial activity of normal animal urine:
–normal voiding of urine
–low pH
–high osmolality.
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CYSTITIS- causes
* Bacterial infections: bacteria involved are similar to those causing pyelonephritis.
* Due to formation and accumulation of uroliths.
* Exposure to toxic compounds (less common)
–ingestion of blister beetle in alfalfa (cantharidin toxicity in horses)
–Ingestion of bracken fern (enzootic hematuria in cattle);
–treatment with cyclophosphamide (dog, cat)
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Suppurative cystitis in a dog.
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Braken Fern in Cattle
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Acute cystitis
* Mucosal hemorrhage and ulceration.
* Production of exudate (hemorrhagic, fibrinopurulent).
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Acute cystitis
238
Chronic cystitis
•Mucous metaplasia of transitional epithelium.
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Multifocal lymphoid hyperplasia, also known as follicular cystitis.
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Formation of mucosal polyps, also known as polypoid cystitis.
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Cystitis
Emphysematous cystitis develops in some dogs and cats with diabetes mellitus.
Glucosuriaprovides a good growth media to bacteria.
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Cystitis
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Feline Lower Urinary tract disease/ Feline Urological Syndrome
– A common condition of male cats.
– Characterized by obstruction of the urethra by a urethral plug.
– Plug is composed of a mixture of protein, cellular debris and struvite.
-Diet high in magnesium and phosphate.
Alkaline urine pH.
Decreased fluid consumption.
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Feline Lower Urinary tract disease/ Feline Urological Syndrome
245
Feline Lower Urinary tract disease/ Feline Urological Syndrome
246
Feline Urological Syndrome- pathogenesis
* Complex and multifactorial.
* Bladder infection by viruses.
* Inhibition of urethral growth by early castration
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Feline Urological Syndrome- pathogenesis
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Feline Urological Syndrome- gross features
Bladder is distended.
The mucosa has red discoloration, often diffuse and transmural.
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Feline Urological Syndrome-
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NEOPLASTIC DISEASES
* Primary tumors of the urinary tract are rare.
* Bladder tumors are seen more often than renal tumors.
* Frequency:dogs\>cats\> other species
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Transitional cell carcinoma- urinary bladder- canine
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Primary epithelial tumors
• Renal adenocarcinoma
-Renal adenocarcinoma
• Renal cystadenocarcinoma
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Renal adenocarcinoma
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RENAL ADENOMA EQUINE
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RENAL CARCINOMA IN A MULE. CUT SURFACE
256
RENAL CARCINOMA
257
Primary urinary tumors
Nephroblastoma (embryonal nephroma, Wilm`s tumor)
Common in pigs, rats and chickens, also diagnosed in cattle and dogs
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Nephroblastoma
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Transitional cell papilloma in ureter
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Transitional cell carcinoma
Transitional cell carcinoma
•Possible exposure to carcinogens:
–transitional cell carcinoma of bladder in dogs exposed to
insecticide dips;
–enzootic hematuria in cattle ingesting bracken fern (Pteridium spp):
• Multifocal raised nodules or focal thickening (plaques) of the urinary bladder, commonly in the trigone region
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Transitional cell carcinoma
263
TRANSITIONAL CELL CARCINOMA IN A DOG
264
Primary mesenchymal tumors
leiomyoma/ leiomyosarcoma
fibroma/fibrosarcoma
hemangioma/ hemangiosarcoma
265
Embryonal rhabdomyosarcoma in the urinary bladder of a young dog
266
Rhabdomyosarcoma. Canine urinary bladder.
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Renal lymphosarcoma in a cat
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Metastatic tumors of the kidney Malignant melanoma
