Flashcards in SA Urogenital Deck (228)
What is the definition of feline idiopathic cystitis?
Abnormal voiding behaviour after exclusion of other disorders
No obvious cause
May be a one-off, or may be chronic/recurrent
What are the 2 divisions of feline lower urinary tract disease?
Obstructive and non-obstructive
Give some causes of non-obstructive feline lower urinary tract disease
Idiopathic cystitis (most common)
Bacterial infection (common in dogs, rare in cats)
Give some causes of obstructive feline lower urinary tract disease
Bladder stones and bacterial infections
What is feline lower urinary tract disease?
Collective term for signs of lower urinary tract disease and abnormal voiding behaviour
What age of cats is more commonly affected by lower urinary tract disease?
Young to middle-aged neutered cats, 2-6 yrs old
Give some predisposing factors for feline lower urinary tract disease
Give some clinical signs of feline lower urinary tract disease
Dysuria (difficulty urinating)
Pollakiuria (increased frequency)
Inability to urinate (urethral obstruction)
Periuria (urinating in inappropriate places)
How could you gauge whether a cat has obstructive or non-obstructive feline lower urinary tract disease?
Palpate the abdomen-large, often painful bladder if obstructed
Why should you check the penis of a cat with suspected feline lower urinary tract disease?
Can check for signs of self-trauma/crystals/sludge
Penis often blocks at the tip
Describe the pathophysiology of feline idiopathic/interstitial cystitis
Alterations in neurotransmission to and from the bladder -> triggers inflammation
Reduced glycosaminoglycan layer (protects bladder lining)
What is the main trigger of idiopathic/interstitial cystitis?
Cat respond badly to stressful events anyway, certain stressful events will trigger cystitis, can look at their history for other stress-induced signs eg over-groooming, GI changes etc
Urethral plugs in cats are more common in which sex?
Most common cause of obstruction
What does a urethral plug consist of?
Mucus/glycoprotein matrix, often with other substances trapped in the matrix
What types of uroliths are there?
Struvite (magnesium ammonium phosphate) (normally sterile in cats, not in dogs)
Urates (may see with liver disease)
Mixed composition stones
Is bacterial infection a common or rare cause of feline lower urinary tract disease?
How may infection occur (which can lead to feline lower urinary tract disease)?
Usually iatrogenic (eg catheterisation)
Secondary to urolithiasis, anatomical defects or neoplasia
Which kind of cats are more prone to bacterial infection of the urogenital tract?
Older cats with CKD and poorly concentrated urine
Which neoplasia is more common in the bladder of dogs and cats?
Transitional cell carcinoma
More rare in cats than dogs
Give some inherited and acquired anatomical defects of the urogenital tract
-Phimosis (inability of the prepuce to be retracted behind the glans penis)
-Strictures due to trauma
What biochem results may you see on a blood sample of a cat with feline lower urinary tract disease?
Hyperkalaemia (potassium is normally exreted out in urine)
Hyperphosphataemia (phosphate is normally exreted out in urine)
How should you examine the urine of a cat with suspected feline lower urinary tract disease?
Dipstick for haematuria, proteinuria, pH
Sediment analysis (RBC are common +/- WBC, epithelial cells)
Crystals are a normal finding
Specific gravity (highly concentrated predisposes to urolith formation, diluted predisposes to bacterial infection)
Culture and sensitivity (recurrent/persistent cases)
What should you make sure you include when radiographing the urinary tract?
ALL of the urinary tract, including penile urethra
What does US allow you to see when investigating feline lower urinary tract disease?
Thickened bladder walls
Uroliths and acoustic shadowing
When would a cystotomy be indicated in a cat with lower urinary tract disease?
Removal of uroliths that can't be dissolved medically
Biopsy of the bladder wall
How should you approach treatment of feline lower urinary tract disease?
Treat specific/underlying cause
If no obvious underlying cause, treat as idiopathic cystitis
How would you treat urethral plugs?
Sedate and use catheter to flush plug back in, then flush bladder 4-5 times with warm saline
What could happen if you don't treat a urethral plug?
Could develop post-renal azotaemia within 24hrs
Bladder may rupture
How could you investigate whether or not fluid in the abdomen was urine from a ruptured bladder?
Take some fluid and measure creatinine (not urea as this travels quickly across perioneum)
How would you treat struvite uroliths?
Dissolve with medical dissolution diet
How would you treat calcium oxalate uroliths?
How would you treat other uroliths?
Encourage water intake
Use diet to prevemt recurrence
How would you treat feline interstitial/idiopathic cystitis?
Most cases resolve spontaneously within 5-10 days
Corsticosteroids and antibiotics have no positive effects!
Reduce stress (eg feliway)
Encourage water intake to create dilute urine (wet diet, water fountain etc)
Could give GAG supplements (decrease bladder permeability) but no significant difference
Analgesia and anti-inflammatories (eg butorphanol)
Tricyclic antidepressants (amitriptyline), chronic cases
Give some causes of stress for a cat
Changes in diet
Which tricyclic antidepressant may be used in cases of feline interstitial/idiopathic cystitis?
Amitriptyline 2.5-20mg/cat q 24hrs (evenings)
Reserve for long-term treatment
Anticholinergic (increases bladder capacity)
Give some side effects of amitriptyline (tricyclic antidepressant used to treat feline idiopathic cystitis)
May cause drowsiness or urinary retention
Raised liver enzymes, neutropenia and thrombocytopenia
How would you treat a urethral spasm?
Give a negative side effect
Smooth muscle antispasmodics
May help reduce severity of signs and prevent urethra re-blocking
May cause hypotension
When does azotaemia occur?
When 75% of nephrons are damaged and not working
Can you have end-stage glomerulopathy without azotaemia?
Yes, as nephrons can function with a damaged glomerulus
Define acute kidney injury
Any damage to the kidney present for less than 3 months
Give some clinical signs of acute kidney injury
Give some causes of acute kidney injury
Secondary to systemic disease
Define chronic kidney disease
Any structural or functional change that is present and stable for over 3 months
In which 5 ways can CKD become apparent?
Slow deterioration of renal function over time
Previously healthy kidney -> episode of AKI -> progresses to CKD
A congenital condition becomes a problem
Acute or chronic episode -> accelerating decline
A neoplastic process expands/invades
Give some causes of renal damage that would be staged as Stage 1 CKD
Reduced renal concentrating ability
Early neoplastic change
Structural change (eg renal cyst)
Presence of renal proteinuria
Define glomerular filtration rate
Amount of ultrafiltrate that passes through the glomerulus
Measured in ml/kg/hr
What is the most accurate way to assess glomerular filtration rate?
Measure the renal clearance of an exogenous substance eg insulin, iohexhol, or injected/exogenous creatinine clearance
However, these are all affected by pre-renal factors eg dehydration, hypotension
What 3 things must an animal be before you assess glomerular filtration rate?
How do urine and serum creatinine levels change with renal and pre-renal damage?
Pre-renal: high urine excretion of creatinine
Renal: low urine excretion of creatinine and high serum creatinine
What is the definition of a glomerulopathy?
Any damage to the glomeruli of the nephrons
What is the classical clinical sign of a glomerulopathy?
Proteinuria (used a method of diagnosis; >2.0)
Which dog breeds are prediposed to glomerulopathies?
Give the pathophysiology of glomerulopathies
Deposition of immune complexes in the glomeruli (Type III hypersensitivity reaction) or
Antibody production against the glomerulus (Type II hypersensitivity reaction)
-> local damage to the glomerulus by inflammation
-> leakage of proteins through glomerulus into urine
Can also get amyloid plaque deposition- high levels of proteinuria
Which breeds are more prone to amyloid plaque deposition in their glomeruli (renal amyloidosis)?
Give some causes of glomerulopathies
Familial (eg shar pei, beagle)
Infectious (eg Lepto, sepsis, pyometra, pyelonephritis)
Inflammatory (eg severe pancreatitis)
When would you suspect a glomerulopathy?
Sick animal with proteinuria that does not resolve with treatment (eg has pancreatitis/sepsis)
Animal with newly diagnosed azotaemia and/or high urine protein
Hypertension of unknown origin
At risk breeds
What is the gold standard method for diagnosing glomerulopathies?
Give some problems with this method
Biopsy, but is expensive, high risk of bleeding, doesn't change tx options
What should you do after getting a positive dipstick result for proteinuria?
Quantify this result using the urine protein:creatinine ratio
Most easily confirmed by taking a cystocentesis sample and analysing haem and biochem
Should also confirm persistence of proteinuria by having proteinuria in 3 samples, 2 weeks apart
You should only start treatment for a glomerulopathy after proteinuria is confirmed to be which 3 things?
Persistent (3 measurements, 2 weeks apart)
Quantified (do UP:C)
Which values for proteinuria suggest glomerulopathy and which suggest tubulointerstitial lesions?
>2.0 suggests glomerulopathy
<2.0 suggests tubulointerstitial lesions
For which values of proteinuria for dogs and cats would you start treatment?
How do you treat proteinuria?
How does it work?
What may happen as a result?
Ace inhibitors (benazapril)
Reduces efferent arteriole pressure -> reduced GFR -> reduced pressure in glomerulus
Mild effect on BP
Reduced GFR may cause an increase in azotaemia, phosphate, potassium, serum creatinine (monitor?)
Why does hypercoagulability occur with glomerulopathies?
Due to loss of anti-thrombin III
Give some treatment options for hypercoagulability associated with glomerulopathies
Low-dose aspirin (diluted)
Clopidogrel (inhibits platelets)
Dalteparin (inhibits factor X)
Give a problem with hypertension
Can cause end-organ damage (eyes, heart, kidneys, liver, CNS)
What is the standard treatment for hypertension?
What is the target value?
Target: 150mmHg systolic
How can you alter diet when treating glomerulopathies?
Restrict protein (reduces proteinuria and azotaemia)
Omega-3 supplementation (reduces glomerular inflammation)
Renal diet if azotaemic (stage 3 in dogs, stage 2 in cats)
Why is it important that an animal eats when it has azotaemia?
Starvation results in catabolism of body proteins -> increased protein through kidneys
Summarise how you'd treat a glomerulopathy
Ace-inhibitors or angiotensin receptor blockers (eg benazepril, to reduce proteinuria)
Anti-hypertensive medication (amlodipine)
Anti-thrombotic medication (loss of anti-thrombin III)
Diet (restrict protein, omega 3 supplementation)
What is the general prognosis time for dogs with a glomerulopathy and no azomtaemia?
What would you suspect in a dog with a 24hr history of severe vomiting, collapse, intense abdominal pain and mild diarrhoea?
Why should you sometimes be skeptical when measuring urine P:C ratio in the vets?
UP:C will increase in the vets due to stress
What would you give to a dog with CKD with increased phosphate?
Renal amyloidosis in Shar peis can result in what?
High levels of proteinuria
Commonly preceded by episodes of 'Shar pei fever'-self-limiting swollen hocks/pyrexia
Commonly leads to nephrotic syndrome
How would you treat renal amyloidosis (Shar peis)?
Typical treatment for a glomerulopathy plus colchicine +/- DMSO
What is the method of inheritance of polycystic kidney disease?
Depends on breed (persian, ragdoll, british short hair, WHWT)
Is autosomal dominant
How is polycystic kidney disease characterised?
Cysts in the kidney and also liver (slowly progressive)
What is nephrotic syndrome?
When is it seen?
Severe loss of protein from the glomerulus
Often seen in severe/end-stage glomerulopathies and common in amyloidosis
How is nephrotic syndrome characterised?
What is the prognosis like for nephrotic syndrome?
Very poor-12.5 days (due to low oncotic pressure)
Which fluids should you avoid in dogs with nephrotic syndrome?
Give some pre-renal causes of acute kidney injury
Decreased renal blood flow caused by:
(Causes decreaed GFR and mild azotaemia)
Is pre-renal acute kidney injury reversible?
Yes if corrected in time
Give some causes of renal parenchymal disease
Intrinsic renal parenchymal disease
Systemic diseases targeting kidney
Give some causes of ischaemia which can then lead to renal parenchymal disease
Renal vasoconstriction (prostaglandin inhibitors)
Pancreatitis, peritonitis, vasculitis
Give some toxins which can cause renal parenchymal disease
Chemotherapy drugs (cisplatin)
Radiographic contrast media
NSAIDs (eg ibuprofen)
Organic compounds (ethylene glycol)
Give some intrinsic conditions that cause acute kidney injury
Infectious (leptospirosis, FIP, leishmaniasis)
Pyelonephritis, septic emboli
Give some systemic diseases that cause acute kidney injury
Multiple organ failure
Describe the 4 stages of acute kidney injury
Initiation phase: damage starts
Extension phase: ischaemia, hypoxia, inflammatory response, ongoing cellular injury, cell death
Maintenance phase: GFR stabilises, azotaemia, uraemia, variable urine production
Recovery phase: azotaemia improves, tubules undergo repair, can have marked polyuria
How do you diagnose acute kidney injury?
History (recent anorexia, PD, vomiting, diarrhoea, toxin exposure? Signs of infection?)
Physical exam (dehydration, uraemic breath, hypothermia, tongue/buccal ulceration, +/- kidney pain/enlargement, occasional neuro signs)
Bloods (azotaemia, hyperkalaemia, metabolic acidosis, increased PCV, TP)
Urine (isosthenuria, can see glucosuria and haematuria, look at sediment for casts, WBCs, bacteria, crystals)
Imaging (radiography: kidney size, shape, opacity, ureter, bladder, urethra. US: renal size, parenchyma, echogenicity)
How big should the kidney be in dogs?
What about cats?
Dogs: 2.5-3.5 x L2
How can you differentiate between acute and chronic kidney injury?
Previous history of PUPD/poor appetite/GI signs
Kidneys typically small, firm, irregular
Often not ill
Normal or low potassium
Poor hair coat
Acute onset of signs +/- history of toxin exposure
Kidneys may be enlarged/painful
May be ill +/- hyperkalaemia
May be casts in urine
Good hair coat
What is the antidote for ethylene glycol poisoning in cats?
Ethanol (needs to be given within 8 hours)
Prognosis poor if already azotaemic/oliguric
Which crystals can you see in the urine of a cat with ethylene glycol poisoning?
Calcium oxalate monohydrate
Which supportive treatment can you give animals with acute kidney injury?
Correct hydration status, acid-base status, electrolytes
Monitor hydration, MM, PCV, CRT, HR, RR, BP, biochemistry
What treatment can you give to increase urine output?
Furosemide (increases urine output but does not inprove GFR or outcome)
How can you correct hyperkalaemia?
Fluid therapy (0.9% NaCl or Hartmanns)
Calcium gluconate 10% (doesn't lower K but is an antagonist of the cardiac effects of hyperkalaemia)
Dextrose (stimulates insulin secretion)
Insulin (facilitates the uptake of glucose into the cell, which brings potassium with it)
Sodium bicarbonate (K+ moves into cells in exchange for H+)
Which drugs could you give to reduce vomiting?
H2 antagonists (eg ranitidine), proton pump inhibitors (eg omeprazole)
Maropitant, metoclopramide, ondansetron
Which drugs could you give to reduce hypertension?
Exacerbated by overhydration; reduce IVFT and give diuretics
If persistent, can give antihypertensives (most are oral)
What should you consider if you can't induce diuresis in a pet with acute kidney injury?
Dialysis (referral; haemodialysis or peritneal dialysis)
Whar is the prognosis for acute kidney injury in cats and dogs?
Dogs: 53-60% mortality
Cats: 50% mortality
What is the definition of pyuria?
WBCs in urine
What is the definition of a UTI?
The adherence, multiplication and persistence of an infectious agent in the urogenital system
Give some routes of infection of a UTI
Upper urinary tract infections are most commonly infected by:
Give some clinical signs of an upper UTI
Give some clinical signs of a lower UTI
How may blood results differ between upper and lower UTIs?
Lower UTIs: unremarkable
Upper UTIs: bloods may be consistent with septicaemia or renal failure
How do you diagnose a UTI?
Urine culture=gold standard (bacteria)
Urine sedament exam (WBC >5 per hpf, microburia, pyuria)
How do we choose an appropriate antibiotic for a UTI?
Agar disk diffusion
Antimicrobial dilution technique (MIC)
An antimicrobial agent must be able to attain a urinary concentration that exceeds the MIC of the uropathogen by how much?
At least four times
How do we treat UTIs?
Eradication of underlying causes if possible (eg diabetes mellitus, CKD, hyperadrenocorticism)
Which antimicrobials are a first-line treatment for UTIs?
How can we prevent UTIs?
Avoid indiscriminate use of urinary catheters (use a closed collection system, avoid indwelling catheters in immunocompromised patients)
Risk of UTI infection increases with duration of catheterisation
What is the difference between complicated and uncomplicated UTIs?
Uncomplicated=no underlying structural, neurological or functional abnormalities
How would you treat an uncomplicated UTI?
10-14 days course of antibiotics
If possible, a urine culture should be performed 5-7 days after therapy ends
How would you treat a complicated UTI?
Antimicrobial therapy for 4-6 weeks
Intact male dogs with UTI should be assumed to have prostatic infection, consider blood-prostate barrier
Which type of animals are more likely to have a complicated UTI?
Sexually intact dogs
Animals with predisposing factors for UTIs
Animals with upper respiratory tract infections
Give some possible complications of bacterial urinary tract infections
Is bacterial cystitis common or rare in cats?
How does the bladder receive sympathetic innervation during the filling stage?
How does the bladder receive somatic (voluntary) innervation during the filling stage?
How is relaxation of the bladder achieved?
Sympathetic action on beta-adrenoceptors in detrusor muscle
How is contraction of the bladder achieved?
Sympathetic action on alpha-adrenoceptors in urethral smooth muscle and trigone
Also somatic innervation of urethral striated muscle and inhibition of detrusor reflex
What innervation does the bladder receive during the emptying phase?
Parasympathetic nervous system predominates via the pelvic nerve (contraction of detrusor, relaxation of urethral muscle: detrusor reflex)
How is urinary continence achieved?
Brainstem micturition centre integrates urethral and detrusor function
Cerebral cortex gives voluntary control by over-riding the detrusor reflex
How can you investigate urinary incontinence?
Biochem and haematology
FeLV test (cats)
Urine culture and sensitivity
Observe patient urinating
-Plain abdominal radiographs
-Intravenous urogram (opacification of kidneys and ureters)
-Retrograde (vagino) urethrogram
-US of urinary tract
Give some typical findings of abnormalities of the filling phase of the bladder
Patient can urinate normally but dribble urine between urinations
Often have reduced bladder capacity
Give some differential diagnoses for abnormalities of the filling phase
Reduced pressure at bladder neck
Urge incontinence (can't hold it in when they need the toilet)
Why may an animal have reduced pressure at the bladder neck?
Congenital USMI (urethral sphincter mechanism incompetence)
Bladder neck mass (polyp/neoplasia/cystic calculus)
Give some causes of urge incontinence (patient knows it needs the toilet and can't hold it in)
Neoplasia of bladder neck
Give some typical findings of abnormalities of the emptying phase of the bladder
Constant dribbling of urine ?
No normal urination
(Overflow incontinence as bladder is full)
Give some differential diagnoses for abnormalities of the emptying phase
Partial/complete urethral obstruction
Chronic distension of bladder (urethral obstruction, pelvic trauma, intervertebral disc protrusion, feline dysautonomia)
What is a non-neurogenic incontinence?
Urethral sphincter mechanism incontinence
Commonest cause of incontinence in bitch
Intermittent involuntary passage of urine, usually while dog is relaxed
Do not constantly dribble urine
Give the aetiology of a USMI
Low urethral tone
? Hormonal influence
? Intrapelvic bladder
Acquired USMI usually affect which dogs?
Medium/large breeds (Dobermans, boxers, irish setters)
Usually neutered females
Congenital USMI usually affects which dogs?
Juvenile bitches (prior to first season)
50% resolve after first season
How do you medically treat a USMI? (urethral sphincter mechanism incontinence)
Increase muscle tone (phenylpropanolamine, estriol)
Reduce contributing factors (weight loss, treat secondary UTI)
How do you surgically treat a USMI? (urethral sphincter mechanism incontinence)
How is a colposuspension carried out?
Caudal midline coeliotomy
Pull bladder cranially
Reposition bladder neck in abdomen
Suture vagina to prepubic tendon
Increases pressure in urethra as it is now sandwiched between vagina and pubic brim
What is the prognosis like for a colposuspension?
20% no better or worse
Acquired USMIs in male dogs typically affect which kind of dogs?
Older, castrated, medium/large breeds
How could you treat an acquired USMI in a male dog?
Describe ectopic ureters
Congenital anomaly, ureter bypasses bladder to empty into urethra, vagina or rectum
Can be intramural (more common) or extramural
Dribble urine all the time
More common in females
Which dog breeds are more prone to ectopic ureters?
Golden labradors/retrievers, skye terriers, siberian huskies
How do you treat an ectopic ureter?
Treat associated UTI
Early surgical management (before irreversible secondary changes)
Technique depends on whether uni/bilateral and intra/extramural
Which surgery options are available when treating an ectopic ureter?
Ureteronephrectomy (removal of kidney and ureter; used for unilateral ectopia, severe hydronephrosis)
Ureteral transection and re-implantation (extramural ectopia)
Intravesical repair (intramural ectopia)
How may an acquired ureteral ectopia occur?
Ureters may be ligated during ovariohysterectomy, usually by inclusion in the cervical ligature
Severe hydronephrosis may develop (reversible if ligature removed in 1 week)
May develop uretero-cervical fistula
What is the most common cause of urinary incontinence in cats?
Neurogenic (eg tail pull, sacral fracture, poor prognosis if no improvement after 6 weeks)
Give some other less common causes of feline urinary incontinence
Juvenile urinary incontinence (ectopic ureter, hypoplastic urethra/vaginal aplasia)
Iatrogenic (eg after perineal urethrostomy)
What are the 3 types of ureteric obstruction?
Give some causes of intraluminal ureteric obstruction
Give some causes of intramural ureteric obstruction
Tumour (v. rare)
Give some causes of extraluminal ureteric obstruction
Compression or invasion by abdominal tumour/mass
Ligation during spay
Uterine stump infection
What can happen if there is prolonged ureteric obstruction?
Reversible if obstruction is relieved within 7 days
How would you diagnose ureteric trauma (avulsion)?
May see electrolyte abnormalities as urine accumulates in retroperitoneal space
Renal function tests may be unaffected if unilateral injury
Definitive diagnosis requires IV urography
How may ureteric trauma (avulsion) occur?
Blunt abdominal trauma, ballistic injuries
How do you treat ureteric trauma (avulsion)?
Correct electrolyte/metabolic abnormalities
Management depends on site and severity of injury:
-Ureteral avulsion at kidney (ureteronephrectomy)
-Mid-ureteral trauma (mild tears may spontaneously resolve, surgical repair)
-Avulsion at bladder (re-implantation)
Define chronic kidney disease
Structural or functional abnormalities of one or both kidneys that have been there for 3 months or longer
Adaptive changes have already occurred
Irreversible, slowly progressive
An abnormal concentration of urea, creatinine and other nitrogenous compounds in the blood
Can be pre-renal, renal or post-renal
Clinical syndrome that results from loss of kidney function, involving multiple metabolic derangements
Give some congenital causes of CKD in dogs and cats
Polycystic kidney disease
Give some acquired causes of CKD in dogs and cats
Idiopathic tubulointerstitial nephritis
Sequel to AKI
Hypokalaemia in cats
Give the pathology of CKD
Precipitation of calcium phosphate in renal tubules
Of cats and dogs, which are more affected by glomerular disease and which by tubulointerstitial disease?
Dogs: glomerular disease
Cats: tubulointerstitial disease
Briefly describe the 4 IRIS stages of CKD
Stage 1: Primary renal injury
Stage 2: Mild azotaemia, maladaptions
Stage 3: Uraemia, systemic complications
Stage 4: End-stage renal failure
Give the clinical signs of CKD
Dullness, lethargy, sleeping more
Signs related to hypertension
Oedema/ascites in severe protein-losing CKD
What may you see in a physical exam of an animal with CKD?
Poor body condition
Osteodystrophy ('rubber jaw')
What 3 criteria do you need for the staging of CKD?
Creatinine concentration (GFR estimate)
Give the plasma creatinine concentrations for the 4 stages of the IRIS staging system of CKD in dogs
Stage 1: 0-125umol/l
Stage 2: 125-180
Stage 3: 180-440
Stage 4: >440
Give the plasma creatinine concentrations for the 4 stages of the IRIS staging system of CKD in cats
Stage 1: 0-140umol/l
Stage 2: 140-250
Stage 3: 250-440
Stage 4: >440
Give the values of urine protein:creatinine ratio that represent non-proteinuria, borderline proteinuria and proteinuria
Borderline proteinuria: 0.2-0.5
Which dog breed is more prone to fanconi-like syndrome?
Which cat breed is more prone to polycystic kidney disease?
Sub-stages of CKD are based on what 2 things?
Which criteria must we use when staging CKD?
Animal must be hydrated
Creatinine must be stable (ie take 2 samples 2 weeks apart)
What are the minimal things you must do when investigating CKD?
Physical exam (eyes, thyroid)
Haem and biochem
What are the end-organs?
Eyes, brain, heart, kidneys
How does muscle mass affect creatinine?
Higher muscle mass -> higher creatinine
What may you see on a haematology of CKD?
Normocytic, normochromic non-regenerative anaemia
What may you see on a biochem of CKD?
Azotaemia (increased urea and creatinine)
Increased or decreased total calcium (usually increased total calcium with normal-low ionized calcium)
Decreased potassium (cats, not usually dogs)
Decreased albumin in protein-losing nephropathies
Give some differential diagnoses for high blood urea
High protein diet
What does increased phosphate lead to?
Linked to increased mortality and progression of CKD (calcium and phosphate interact and can cause tissue damage)
Give some clinical signs of low potassium in cats
Neuromuscular signs (ventral neck flexion)
Decreased renal function
What happens to blood potassium concentrations during end-stage CKD?
What value for urine specific gravity would you expect in a dog or cat with CKD?
Isosthenuria with azotaemia usually = renal azotaemia.
What are the 3 exceptions?
Animal on diuretics
What would you look at on a radiograph when investigating CKD?
Kidney size, shape, opacity
What should you asses on an US when investigating CKD?
Renal size, parenchyma, echogenicity
How should you take a BP measurement?
Cuff should be 30-40% circumference of leg. Keep pet calm. Discard first reading until you get 3 or 4 consistent readings
What other tests could you do when investogating CKD?
FNA or kidneys
Is CKD reversible?
Is there a cure?
How do you generally manage CKD?
Stop all potentially nephrotoxic drugs
Treat any pre/post-renal abnormalities
Eliminate any ongoing specific disease
Start supportive medical management (to reduce severity and minimise progression)
How would you treat a uraemic crisis?
IVFT (Hartmann's or 0.9% NaCl)
Supply ongoing maintenance requirements
Monitor electrolytes and azotaemia
Reduce IVFT as animal starts to eat and drink
How would you reduce proteinuria?
Look for any concurrent associated disease
Consider kidney biopsy
Ace inhibitors plus dietary protein reduction
Low-dose aspirin if serum albumin is <20g/L
Monitor response to treatment
When are ace inhibitors contraindicated in the treatment of CKD?
In dehydrated or hypovolemic patients
When treating CKD, what value do you want to reduce BP to?
How do you reduce blood pressure in dogs?
1) ACE inhibitors at standard dose rate
2) ACE inhibitors at double dose
3) Combine ACE inhibitors and calcium channel blockers
Give an example of a calcium channel blocker used in the treatment of high blood pressure
How do you reduce blood pressure in cats?
1) Calcium channel blockers at standard dose rate
2) Increase dose of calcium channel blocker (up to 0.5mg/kg/day)
3) Combine ACE inhibitors and calcium channel blocker
How can you address dehydration in cats?
Drinking fountains/dripping taps
Chicken/fish flavoured water
What are the 3 recommendations for a cat/dog in Stage 1 CKD?
-If proteinuric, start ACE inhibitor or ARB (angiotensin-receptor blocker)
What are the 3 recommendations for a cat/dog in Stage 2 CKD?
-Start renal diet (if cat, stage 3 if dog)
-Control phosphate to <1.5mmol/l
-Supplement potassium if needed
Why are renal diets beneficial?
Reduced protein (reduces PUPD, risk of uremic crisis, acid load)
Omega-3 fatty acids
When should renal diet be given to dogs and cats?
Dogs: Stage 3 CKD, or Stage 2 with phosphate >1.5mmol/L, or all dogs with proteinuric CKD
Cats: Stage 2 CKD
How can you maximise the chances of a pet accepting a renal diet?
Don't introduce during times of stress (eg in hospital)
Consider temperature/texture etc
Add flavour enhancers
Try another brand
How can you reduce serum phosphate in pets with CKD?
Renal diet best way-restricts phosphate and protein intake
Add phosphate binder if diet alone isn't enough
Give some examples of phosphate binders used in the treatment of CKD
What are the target values for serum phosphate in pets in stage 2, 3 and 4 CKD?
Stage 2: <1.5mmol/L
Stage 3: <1.6mmol/L
Stage 4: <1.9mmol/L
What value for serum potassium would you aim for in pets with hypokalaemia?
How can you avoid hypokalaemia in pets with CKD?
Supplement IVFT with KCl
Oral supplements (potassium gluconate, potassium citrate)
What are the recommendations for a cat/dog in Stage 3 CKD?
-Start renal diet (dogs)
-Supplement potassium if needed
-Control phosphate to <1.6mmol/L
-Treat nausea and vomiting
-Control metabolic acidosis
-Consider EPO (erythropoietin)
-Consider SC fluids
How can you control vomiting/nausea?
Reduce gastric acid secretion with eg ranitidine, famotidine, omeprazole
Sucralfate (protects the GI tract from stomach acid)
Which drugs can you give to stimulate appetite?
Consider feeding tube
Give some possible complications of SC fluids
Hypernatraemia (high blood sodium)
How can you control constipation?
Lactulose 0.5-5ml/cat q 8-24hrs
May need enema
How can you control metabolic acidosis?
How often does metabolic acidosis occur in cats with CKD?
<10% of cats with Stage 2 CKD
50% of cats in uraemic crisis
How can you manage anaemia in cats with CKD?
Avoid excessive blood sampling
Minimise GI blood loss
Treat iron deficiency
EPO replacement (recombinant human EPO; supplement iron if you give EPO)
What should you supplement if you give EPO to an anaemic cat with CKD?
Give some side effects of EPO given to cats with CKD
Seizures, hypertension, local reactions
Why might you give calcitriol in the treatment of CKD?
Can promote hypercalcaemia and hyperphosphataemia. Inhibits PTH
May prolong survival and reduce progression of CKD in dogs
What must you do before giving calcitriol in the treatment of CKD?
Confirm there is no ionised hypercalcaemia present
What are the recommendations for a cat/dog in Stage 4 CKD?
As for other stages plus:
-Control phosphate to <1.9mmol/L
-Intensify efforts to provide nutrition
-More likely to require extra fluids (SC or via tube)
How often should you monitor a patient with CKD?
-Blood tests, urine, BP, appetite, BW
What would make you suspect hyperkalaemia on a clinical exam of a pet with acute kidney injury?
Describe the urine of a pet with acute kidney injury
Look at sediment for casts, WBCs, bacteriuria, crystals
Give some indications for ovariohysterectomy
Elective (prevents unwanted pregnancies/oestrus/risk of mammary neoplasia)
Prevention and treatment of mammary and ovarian diseases
Control of certain diseases (diabetes mellitus, epilepsy, certain dermatoses)