Metabolism 5 Flashcards
(100 cards)
1
Q
What functional reserve do the kidneys have and what occurs with damage of nephron
A
- large functional reserve but their regenerative capacity is limited
- surviving nephrons undergo hypertrophy
- damaged glomeruli are not replaced surviving undergo hyperplasia
- irreversible damage to one component - impaired function of the other components
2
Q
at what GFR is each occurring at
1) diminished renal reserve
2) renal insufficiency
3) renal failure
4) end-stage renal disease (renal failure)
A
1) 50-99% normal
2) 25-50% normal
3) 20-25% normal
4) 5% normal
3
Q
what is meant by renal disease and renal failure
A
renal disease = any deviation from normal renal structure or function
renal failure = decompensated renal disease with inability of the kidneys to maintain essential homeostatic functions required by the body
4
Q
what are the most common factors responsible for death of animals in renal failure
A
most commonly attributable to severe retention of waste products, metabolic acidosis, hyperkalaemia or iatrogenic overhydration
5
Q
Why are animals in clinical renal failure (uraemia) typically depressed, lethargic, inappetent or anorexic and (at least in small animals) frequently vomiting
A
- failure to excrete nitrogenous waste like urea
- urea itself not toxic but toxic waste products such as potassium, sulphate and phosphate are
- trigger chemoreceptor trigger zone for vomiting
- direct injury to vascular endothelial
- impairment of leukocyte and cardial skeletal muscle function
6
Q
why do uraemic patients become dehydrated what does it result in
A
reduced renal function therefore reduced concentration ability - polyuria
- increased by vomiting or diarrhoea
result in compensatory polydipsia
7
Q
what is anasarca and what factors contribute
A
- anasarca (generalised oedema formation) may reflect hypoalbuminaemia in protein-losing nephropathies (glomerulopathies)
- vascular injury by circulating waste products also promotes oedema formation by increasing vascular permeability
8
Q
What is the most common acid-base imbalance seen in uraemic patients and what clinical sign might suggest that an animal has this imbalance?
A
- metabolic acidosis due to generate ammonium (NH4+) ions, increased retention of H+ ions, and impaired resorption of bicarbonate (HCO3-) ions
- compensatory hyperventilation
9
Q
7 consequences of renal failure
A
1) retention of metabolic waste
2) impaired regulation of fluid volume
3) electrolyte imbalance
4) acid-base imbalance
5) disturbed endocrine function
6) immune dysfunction
7) systemic hypertension
10
Q
List 4 consequences of systemic hypertension caused by decreased liver function
A
1) arteriolar smooth muscle hypertrophy +/- fibrinoid change leading to increased blood pressure (cycle)
2) thrombosis and/or tissue infarction - stoke
3) capillary rupture - haemorrhage - retinal haemorrhage (sudden onset blindness)
4) cerebrovascular accidents (strokes) with acute onset of neurological signs
11
Q
why are animal cachexia in renal failure
A
- anorexia, vomiting +/- diarrhoea and subsequent catabolism of body tissues
12
Q
vascular lesions why occur and what are the consequences
A
due to circulating uraemic toxins
leads to - hyaline degeneration (tunica intimal/medial deposits of collagen, amyloid) or fibrinoid change
- can lead to tissue haemorrhage, oedema, thrombosis and/or infarction
13
Q
what lesions occur in oral cavity and what is the cause
A
ulcerative stomatitis on ventral aspect of the tongue, floor of the oral cavity, the gums and inner lips and cheeks
1) secretion of excess urea in saliva and conversion to ammonia (NH3) by urease-positive bacteria in the oral cavity - direct chemical mucosal injury
2) ndamage to submucosal arterioles by circulating toxins - thrombosis and ischaemic necrosis of the overlying mucosa (hypoxia)
14
Q
what is uraemic gastritis, in what species most common, clinical symptoms and cause
A
- gastric mucosal ulceration and haemorrhage - vomiting, haematemesis and melaena in uraemic dogs
- similar pathogenesis to ulcerative stomatitis
15
Q
4 other consequences that occur in the stomach due to renal failure
A
1) secondary bacterial infection
2) swollen and intensely congested
3) dystrophic mineralisation of gastric mucosa
4) dehydrated may develop constipation
16
Q
List the 8) lesions caused by renal failure
A
1) gastrointestinal
2) exocrine pancreatic
3) cardiac and pericardial
4) lung
5) soft tissue
6) skeletal
7) brain
17
Q
What are the cardiac/pericardial lesions that you might find in an animal in renal failure, what causes these lesions and how heal
A
1) hydropericardium (distension of the pericardial sac with noninflammatory oedema fluid)
○ may be due to vascular injury and increased vascular permeability
2) ulcerative uraemic mural endocarditis of the left atrium
lesions heal by scarring with dystrophic mineralisation
18
Q
what is uraemic pneumonopathy
A
dogs in CRF may develop severe pulmonary dystrophic mineralisation and oedema with fibrin exudation into the alveolar lumina
19
Q
what is a lung lesion caused by liver failure and what caused by
A
terminal pneumonia (e.g. due to vomiting and aspiration of feed or gastric secretions, or because of immunosuppression)
20
Q
where find mineral deposits in renal failure
A
mineral deposition in damaged arterioles, the stomach wall, lungs, kidneys and subcutis (especially footpads)
21
Q
what is secondary renal hyperparathryoidism
A
hyperphosphataemia (due to decreased GFR) - decreased serum ionised calcium concentration - hyperplasia of the four parathyroid glands with increased parathormone (PTH) synthesis and secretion - bone resorption by osteoclasts to boost the blood calcium concentration to normal - osteoporosis (decreased bone mass) - +/- pathological bone fractures and loosening or loss of teeth
22
Q
what is rubber jaw what species common in
A
facial enlargement and malleability of the maxilla and mandible without fracture (“rubber jaw”)
dogs - puppies
23
Q
what is renal ectopia and does it cause problems and list 2 other congenital malformations
A
malpositioning of one or, rarely, both kidneys generally caudally to pelvic canal
kidney normal may be hypoplastic
1) persistent foetal renal lobations
2) horseshoe kidney
24
Q
define renal dysplasia, how occurs and 2 main features
A
disorganised renal development due to anomalous differentiation
- usually a congenital malformation but may be acquired in the early neonatal period in piglets, kittens or puppies in which nephrogensis continues
1) persistence of structures inappropriate to the stage of development
2) presence of anomalous structures
25
What species does polycystic kidney disease (PKD) occur, what breed and where found
cats - persian cats
| in PKD, multiple renal cysts may be accompanied by cystic intra-hepatic bile ducts and sometimes cystic pancreatic ducts
26
what are Acquired Perinephric Pseudocysts
| and where commonly seen, is it congenital or acquired
- uni- or bilateral - pockets of fluid (urine, blood, lymph or transudate) in the space between the renal capsule and the reflection of the peritoneum onto the kidney
- common in old cats
- caused by trauma, neoplasia, systemic hypertension
27
```
Define
juvenile nephropathy,
familial nephropathy
hereditary nephropathy
list two breeds common in
```
• juvenile nephropathy = a non-inflammatory, degenerative or developmental renal disease of obscure pathogenesis that affects young animals
• familial nephropathy = a more restrictive term used for the same disease when it affects families of animals
• hereditary nephropathy = the definitive term used for the same disease once the inheritance of the nephropathy has been established
- english cocker spaniel and german shepherd
28
features of renal vasculature that predispose kidney to hypoxic injury
- renal artery and branch are end arteries so infarction of all dependent parenchyma is obstruction
- renal medulla is sensitive to hypoxia because of its relatively poor vascularity (most of its blood supply comes from the descending vasa recta) and because the packed cell volume (PCV) in the medullary capillary plexus is low because of water resorption
29
What is the mechanism that ensures that adequate perfusion of juxtamedullary nephrons is maintained following a significant and sustained drop in systemic blood pressure, where released from, what increase release and function
prostaglandins (especially PGE2 and PGF2α) released by specialised cells of the renal medullary interstitium
○ angiotensin II and angiotensin III - increased prostaglandin synthesis
○ the prostaglandins oppose the vasoconstrictive action of the angiotensins and induce vasodilation of the afferent arterioles of the juxtamedullary nephrons
30
define ischaemia, infarction and infact
ischaemia = hypoxic tissue injury resulting from a local reduction in blood flow
infarction = ischaemic coagulative necrosis of a localised area of tissue
infarct = the area of tissue which has undergone infarction
31
what is the no reflow phenomenon in the kidneys and pathogenesis
complete ischaemia longer than 2 hours may result in prevent of reflow of blood due to intravascular swelling of erythrocytes and tubular epithelial cells of glomerular and peritubular capillaries
32
what is reperfusion injury
reperfusion - generation of reactive oxygen species (free radicals) and influx of leukocyte - exacerbation of the original ischaemic damage
33
what patterns of necrosis occurs for the following
1) occlusion of the renal artery
2) occlusion of an arcuate artery branch
3) occlusion of an interlobular artery branch
1) infarction of all or almost all of the kidney
2) infarction of a wedge of cortex and outer medulla
3) infarction of a wedge of cortex
34
what is the cause of renal cortical necrosis what is the gross appearance
circulating Gram-negative bacterial endotoxins - vascular endothelial damage - widespread thrombosis in the renal cortical microcirculation (arterioles, capillaries and venules)
horses - recumbent in shock
turkey egg - grossly speckled cortex
35
what is the most common cause of renal papillary necrosis in horses, pathogenesis and other causes in other species
○ most commonly seen in dehydrated horses treated with phenylbutazone at appropriate doses
○ can also be caused by excessive dosage of NSAIDs
- prostaglandin synthetase in the medullary interstitial cells is inhibited - decreased production of PGE2 - loss of prostaglandin-mediated vasodilation of the afferent arterioles of the juxtamedullary nephron - loss of blood flow in the descending vasa recta - papillary and/or inner medullary necrosis
36
hydronephrosis what is it, what causes it and what results in
dilation of the renal pelvis and calyces due to obstruction of urine outflow
1) obstructive acquired lesions - urinary calculi
2) may be congenital
- pressure increases in the renal pelvis, calyces, and the lumina of the collecting ducts and more proximal nephron segments - pressure atrophy and apoptosis of tubular epithelium - atrophy of obstructed nephrons (including ultimately their glomeruli) and interstitial scarring
37
hydronephrosis is it partial or complete and where would you find the blockage
may be partial or complete, unilateral or bilateral, and lie anywhere from the renal pelvis to the distal end of the urethra
38
what outcome for animal if urine outflow is unilateral at level of ureter in hydronephrosis
massive renomegaly
○ relief of obstruction within approximately one week of onset - complete return of renal function
○ > 3 weeks of complete obstruction or several months of intermittent obstruction - irreversible renal damage
39
nephrotic syndrome when develop and what is it characterised by
marked proteinuria may develop in chronic glomerulonephritis or glomerular amyloidosis
characterised by severe hypoalbuminaemia, ascites - typically low protein transudate and anasarca and hypercolesterolaemia
40
define glomerulitis and glomerulonephritis
• glomerulitis = inflammation restricted to the glomeruli
• glomerulonephritis = inflammation of glomeruli accompanied by secondary adverse
effects on the renal tubules, interstitium and blood vessels
41
what are the two main things that cause glomerulitis and examples
1) viral - infectious canine hepatitis (canine adenovirus - 1)
2) bacteria - bacteraemia or septic thromboembolism
42
what occurs in bacterial glomerulitis with longer survival in terms of lesions
formation of multiple, randomly distributed (but predominantly cortical) foci of necrosis and thence neutrophil-rich inflammation (= acute suppuratives embolic nephritis)
43
what is the most common cause of glomerulonephritis and cause
immune complex glomerulonephritis
= deposition within the glomeruli of soluble circulating immune complexes (antigen- antibody complexes) unrelated to glomerular antigens
cause unknown but thought to be genetic factors
44
where may immune complexes lodge in the glomeruli
1) Under epithelium
2) In mesangium
3) Under endothelium
45
3 gross lesions of kidney of animal with acute glomerulonephritis
- mild or marked renal swelling
- normal colour
- glomeruli visible as tiny red dots
46
5 gross lesions of kidney of animals with chronic glomerulonephritis and what similar to
1) shrunken kidneys
2) renal capsule may be adherent
3) finely granular surface
4) reduced depth of the renal cortices
5) blurred corticomedullary junction
- usually grossly indistinguishable from chronic interstitial nephritis
47
what animal species most often develop glomerular and renal medullary amyloidosis and what consequences
```
glomerular - dogs
- nephrotic syndrome
- severe proteinuria
- renal and glomerular fibrosis
medullary - cattle and most animals
- no significant protenuria
- compress thin-walled medullary blood vessels - papillary necrosis - fibrosis, nephron obstruction and atrophy - renal failure
```
48
What caused the necrotic infarct segment of the large colon and blood clots in the case study Ernie the unfortunate
NSAIDS causes this
- Prostaglandin supress gastric acidic production, increase mucus production and increase blood flow - suppressed
- Ulceration of the right dorsal colon (quite sensitive to changes to blood flow)
- Blood flow to mucosa - dying off of mucosa - ulceration of mucosa - bleeding into the gut
49
what caused the lesions within the kidney (thickened mucosa around pelvis and papillary tissue sloughing, areas of necrosis) in ernie the unfortunate case study
○ Bleeding and fluid loss into the gut - decrease blood pressure - decrease glomerular filtration rate in kidney - activate RAAS - angiotensin II potent vasoconstriction (afferent arteriole) - poor oxygen delivery to the kidney - hypoxic area in the loop of Henle (medulla - vasa recta blood vessels) - prostaglandins can help prevent that from occurring (vasodilation) suppressed with NSAIDS so cannot prevent
- Isn't in renal failure - but necrosis would have become more severe and lead to kidney failure
50
In which domestic animals species does nephrogenesis continue for a few weeks post-natally and what effects does renal immaturity have on renal function in these species
piglets, kittens and puppies
- kidneys have limited capacity to dilute or concentrate urine not usually an issue due to suckling
- however if get anorexia lead to azotaemia, increased blood [uric acid] and profound dehydration
- if urine is yellow then dehydration should be colourless
- glucosuria is very common in puppies under 1-2 weeks of age
51
define osmotic diuresis and what substances in the renal tubular lumina can cause osmotic diuresis and one special name
when presence of substances drag water into the lumina overwhelming of the water resorptive capacity of the distal nephron segments
need to be osmotically active substances - glucose, amino acids, sodium (natruresis)
52
define nephrogenic diabetes insipidus and what clinical signs and causes
there is partial or complete lack of responsiveness of the distal tubules and collecting ducts to anti-diuretic hormone (ADH) - inability to concentrate the urine - water diuresis
1) primary (congenital)
2) secondary (acquired) - structural damage to distal tubule (renal papillary necrosis)
PU/PD - risk of dehydration
53
what causes renal medullary solute washout
faster fluid flow rates through the renal tubules - decreased opportunity for resorption of NaCl and urea into the medullary interstitium - decreased medullary solute gradient (renal medullary solute washout)
54
what are the inherited conditions that can be responsible for renal tubular dysfunction
1) essential cystinuria - defective resorption of cystine - cystinuria
2) primary renal glucosuria - defective resorption of glucose - glucosuria
3) fanconi syndrome - impaired resorption of Na+, K+, amino acids, protein, bicarbonate leading to PU/PD, natriuresis, glucosuria, metabolic acidosis
55
why are dalmantions dogs predisposed to ammonium biurate crystals
1) hepatocellular uptake of uric acid defective
| 2) resorption of uric acid by proximal tubular epithelium from the glomerular ultrafiltrate defect
56
define nephrosis, what are the 2 major causes, what segments are most vulnerable and prognostic of each
degeneration or necrosis (sub-lethal and lethal) of renal tubular epithelium
1) Ischaemic/Hypoxic Nephrosis
- epithelial cells of the proximal tubules and thick ascending loops of Henle as these are highly active metabolically and hence most dependent on an oxygen supply
- poorer prognosis than toxic nephrosis
2) Toxic Nephrosis
proximal tubular epithelial cells are very susceptible to exogenous toxins due to their high metabolic activity and their exposure to and/or resorption of toxins in the glomerular ultrafiltrate
57
what gross features and microscopic seen in kidney in acute phase of nephrosis and how does healing occur in surviving animals
gross
- swollen, pale, wet, bulging, multifocal hemorrhage
microscopic
- undergo hydropic or fatty degeneration
- sloughing into the tubular lamina
- mild infiltration by leukocytes
healing
- tubular basement membrane is intact, surviving tubular epithelium regenerates by mitotic division and hypertrophy
and interstitial fibrosis
58
List 4 common nephrotoxins
1) oxalates (ethylene glycol)
2) heavy metals
3) mycotoxins
4) lillies in cats
59
define oxalate nephrosis what species most commonly affected and what is the cause
- excess in oxalates that cannot be degraded by ruminal bacteria
- seen in cattle and sheep due to ingestion of oxalate-containing plants
- dog and cat with ethylene glycol poisoning
- calcium oxalate crystals may be deposited in vessels walls - vascular injury and haemorrhage and in renal tubules - tubular obstruction and acute renal failure)
60
define interstitial nephritis,, what gross and microscopic lesions for acute and chronic phases and causes for chronic types
inflammation is centred on the interstitial tissues of the kidneys
gross
acute - if mild may not see or diffuse - swelling, pallar
chronic - pale, shrunken, firm, dimpled capsular
microscopic
acute - see interstitial oedema and neutrophilic infiltration, with multifocal tubular degeneration and necrosis
chronic -
1. suppurative (neutrophils) - haematogenous infection bacteria
2. non-suppurative (lymphocytes and plasma cells) - canine adenovirus-1
3) gramulomatous (macrophages)
61
define pyelitis and pyelonephritis and pathogenesis
• pyelitis = inflammation of the renal pelvis
• pyelonephritis = inflammation of the renal pelvis and renal parenchyma
- bacteria ascending from the lower urinary tract via the ureters from cystitis transport up ureter via vesicoureteral reflux
- may ascend into kidney parenchyma via collecting tubules and invade interstitial tissues
62
what promotes reflux up to the kidney and what does it compromise
reflux may be promoted in lower urinary tract infections due to compromise of the vesicoureteral valves, narrowing of bladder outflow by exudate, oedema or uroliths, reversed ureteral peristaltic waves due to endotoxins
63
gross lesions of chronic and acute phases of pyelonephritis and what species most common for each
acute - dark red, swollen wedges of inflamed parenchyma, pelvis may contain pus
- pigs, rapidly fatal
chronic - fibrosis predominates, scars in pelvis and renal capsule, calculus formation
- cows, dogs and sometimes cats
64
what is pyonephrosis
infected and hydronephrotic kidney may be converted into a sac of pus
65
define hypercalcaemic nephropathy, what species most common, list 2 possible causes in dogs
- tubulointerstitial disease caused by hypercalcaemia
- impaired renal function and later metastatic mineralisation of the kidneys - eventual renal failure
- most common in dogs but any species with vit D poisoning
causes
1) hypercalcaemia of malignancy - tumour produce parathryoid hormone
2) hypoadrenocorticism
66
what gross lesions are seen with hypercalcaemic nephropathy
chalky-white deposits grossly, often as a band in the outer medulla
67
name two parasites that cause disease in kidneys an which species most commonly affected
1) Stephanurus dentatus = the kidney worm of pigs
| 2) Dioctophyma renale = the giant kidney worm of dogs
68
primary of secondary neoplasia what most common in kidneys and list 4 types, cell of origin and which associated with paraneoplastic syndrome
secondary
1) renal adenoma - benign - proximal tubular epithelial
2) renal carcinoma - malignant of proximal tubular epithelial
3) renal cystadenocarcinoma - malignant renal epithelial tumour ad macroscopic cysts develop (german shepard have inheritance) and paraneoplastic syndrome where growth factors stimulate proliferatin produced from tumour
4) renal lymphoma - malignant of lymphocytes
69
what is the most common congenital malformation of the ureter, what species commonly affected, clinical signs and and why occur more in females
ectopic ureter
most common in dogs
clinical sign - urinary incontinence (dribbling of urine)
- generally disgnosed more in females probably because males have external urethral sphincter so get retrograde filling of urinary bladder instead of incontinence so less likely to be taken to the vet
- also in bitches usually empties into vagina or urethra
70
what is the most common congenital malformation of the urinary bladder, what species commonly affected and what does this predispose to
patent (pervious) urachus
foals most common
○ failure of post-natal urachal closure dribbling of urine from the umbilicus + increased susceptibility to umbilical infection and abscessation
ALSO may undergo squamous or mucous metaplasia - potential development of bladder tumours
71
what is a bladder diverticulum where most commonly located, why and what does it predispose to
- an outpouching of the bladder wall
- cranioventral vertex of the bladder due to incomplete closure of the urachus
- predisposed to calculus and bacterial infection and inflammation
72
what is the most common congenital anomaly of the urethra and what are affected females predisposed to
Urethrorectal or Rectovaginal Fistula
| - in females, the fistula involves the vagina - predisposition to ascending urogenital tract infections
73
what is the difference between bladder eversion and bladder prolapse and in what circumstances do these develop
eversion - urinary bladder invaginates into and through the urethra
prolapse - displaced in a female through a vaginal tear
- intra-abdominal pressure or straining especially after parturition
74
define bladder atony, what does it look like and feel grossly and what are the 2 major causes and examples
- inability to urinate due to lack of muscle tone
- dilation, wall is thin and may be transparent
- detrusor muscle layer feels flaccid
1) neural injury such as intervertebral disc prolapse in dog
2) prolonged urine outflow obstruction - calculi, neoplasia
75
what is a common adaptive response in bladder of a dog that has a chronic partial urinary obstruction distal to bladder
Bladder Smooth Muscle Hypertrophy
- chronic partial obstruction of urine outflow - work hypertrophy of the detrusor smooth muscle cells - thickening of the bladder wall
76
if there is urine outflow obstruction obstruction at bladder neck what determines whether bladder will rupture and what precedes a bladder rupture
depend on the competence of the vesicoureteral valves (ureteral flap valves)
1) if stay open - pressure may develop hydronephrosis
2) if remain competent - pressure increases within bladder, collapse veins, infarction, bladder rupture
results in uroperitoneum (urine in the peritoneal cavity)
77
what are other potential causes of bladder rupture in domestic animals besides urine outflow obstruction
1) traumatic cateterisation or manual expression
2) birth trauma
3) rare but difficult parturition
4) abdominal trauma in dogs and cats
78
what laboratory test finding would be expected in a animal with uroperitoneum
peritoneal fluid:serum ratio of the creatinine concentration > 2:1 (the peritoneal fluid concentration of potassium and phosphate may also exceed that of peripheral blood by > 2:1)
79
urinary incontinence what are the two main causes in bithces
incompetence of the urethral sphincter/valve
1) short urethra
2) reduced urethral tone
80
what are the 5 major factors that contribute to urolithiasis
1) highly concentrated urine favours supersaturated urine of dissolved salts that may precipitate out
2) retention of urine - give time to grow
3) urine pH favorable to the particular crystal
4) presence of nucleation center of nidus on which crystallisation can occur
5) decreased concentration of crystallization inhibitors
81
what are the potential consequences of urinary tract obstruction of uroliths
- haematuria, dysuria (difficult or painful urination), pollakiuria (increased frequency of urination without an increase in urine volume) and stranguria (painful urination in which the urine is passed drop by drop)
- urine stasis - predispose to bacterial infections of the lower urinary
- urethral rupture
82
males why prone to uroliths, what crystals normally responsible
due to the long and narrow urethra
feline lower urinary tract disease (FLUTD) is more commonly associated with gritty to rubbery plugs of protein, cell debris and struvite crystals, especially in the urethra of male cats
83
what parts of urinary tract contain bacteria and list 6 ways to maintain this sterile environment
only vagina and distal end of male urethra have bacteria
1) normal voiding of urine
2) sloughing of surface mucosal epithelial cells
3) substances that prevent bacterial binding to mucosal membrane
4) urine olgiosaccharides
5) urine acidity
6) high urine concentration
84
list 6 factors which favour bacterial infections in the lower urinary tract
1) incomplete voiding of urine and stasis of urine
2) mucosal trauma
3) urinary incontinence
4) disruption or overgrowth of distal urethral or vaginal flora
5) low urine concentration
6) female
85
list 4 things why females predisposed to urinary tract infections
1) short and relatively wide urethra
2) proximity of urethra to the anus
3) urethral trauma sustained during parturition
4) possible hormone influences
86
what are some non-bacterial causes of cystitis in domestic animals
1) fungal infection
2) viral infection
3) drugs and toxins
87
define feline interstitial cystitis and what are the clinical signs
decreased synthesis of mucosal glycosaminoglycans leading to exposure of submucosa of bladder to urine resulting in local inflammation response leading to increase vascular permeability, oedema and heamorrhage
signs
- dysuria, pollakiuria, intermittent haematuria, sterile urine, and increased prominence of the submucosal vasculature of the bladder with often spontaneous submucosal haemorrhage
88
gross lesions you would see in bladder of animal with acute and chronic cystitis and the different types and example
acute - thickened bladder wall, hemorrhage in bladder submucosa
1. emphysematous cystitis gas bubble formation from CO2 from glucose-fermenting bacteria in diabetes mellitus
chronic - irregular mucosal thickening and hyperplasia
1. follicular cystitis - lymphoid follicles
2. polypoid cystitis - folds or nodules composed of scar tissue
89
what is the most common neoplasm of urinary tract, how does the tumour behave
transitional cell carcinoma (TCC) is the most common neoplasm
- 50% metastasise to lymph nodes and lungs
90
what is botryoid rhabdomyosarcoma and in what species and age is this commonly diagnosed
malignancy that arises from rests of embryonic myoblasts in the urinary bladder or occasionally urethra
especially young dogs (
91
what is enzootic haematuria and pathogensis
syndrome of persistent haematuria and anaemia in cattle
due to chronic ingestion of bracken fern, oncogenic bovine papillomavirus infection
1) causes bone marrow suppression - low platelets
2) micrscopic haematuria
3) metaplasia of mucosa
4) tumour development
5) bleeding ulcerated bladder tumour development
92
tubular reabsorption how does pH relate
passive movement of drugs across tubular membrane only NON ionised (lipid soluble) drug will cross the tubular membrane
○ Many drugs are weak acid or base and therefore change in pH will change the ionisation of the drug and the amount of drug excreted
93
List 3 things why kidneys are susceptible to toxic agents
1) receives 25% blood supply so substances may be concentrated in the kidneys
2) carry out metabolism which creates reactive oxygen species directly damage epithelium
3) change in extra renal factors like blood volume may change perfusion and lead to decrease in function
94
what is important about collecting duct Na+ transport
Apical Na/K exchange - important because only transporter that exchanges Na and K therefore if Na is excreted K can be retained
95
what is diuretic stacking and what is the benefit
Effects of different diuretic agents are additive on natriuresis as have different mechanisms of action and therefore exert effects on different parts of the nephron. This allows for minimisation of biochemical disturbances (electrolyte loss)
96
List the two diuretics that act at the PCT and there effects
1. Carbonic Anhydrase Inhibitor
- Prevents formation of H+ and therefore prevent H+ being exchanged for Na+ at the apical membrane
○ Increase loss of bicarbonate in urine
○ Increase loss of Na+ and water
2. Osmotic diuretics
- Mannitol is a sugar complex that is filtered through glomerulus but cannot be reabsorbed and therefore creates an osmotic drag
97
What is the Loop diuretic called and its effect and potential negative consequences
Frusemide
- Inhibits Na/K/2Cl cotransporter
- Most powerful diuretics
- May cause
○ Hypokalaemia as K+ is secreted into tubular lumen via channel and reabsorbed via the cotransporter that is inhibit by this diuretic
○ Potentiate toxicity of cardiac glycosides
98
What is the DCT diuretic called and its effect and negative effect
- Inhibit Na/Cl luminal cotransporter so drop Na+ and Cl- levels
- Also cause potassium loss due to increased flow rate through collecting duct
○ Hypokalaemia
○ Hypoantraemia - low Na+ blood levels
99
What are the two collecting duct diuretics why are they important and what do they do
- Potassium sparing diuretics
1. Spironolactone: synthetic aldosterone inhibitor
- Decreased luminal Na+ channels
- Decreased Na/K/ATPase on basal membrane - increase loss of Na+ and decreases loss of K+
2. Amiloride triamterene
- Block luminal sodium channels - also decreases loss of K+ as not enough Na+ to exchange with
100
treatment for struvite stone
1) antibitoics - in dissolution may need to be taken for 6 months
2) dissolution diet - reduce intake of minerals, low pH, dilute urine so no supersaturation, possible salty diet to make animal drink more and higher flow rate through the kidney
- cannot be on long term
