Urinary tract disease 3 Flashcards
Outline the clinical signs of lower UTI
- May be none
- Stranguria/dysuria, pollakiuria
- Urine scalding
- Pyuria, haematuria
- Bladder may be painful on palpation, thickened
- Abdominal pain
Outline the clinical signs of an upper UTI
- May be none, often non-specific
- May be pyrexic, abdominal pain
- Kidney may be enlarged, painful
- PUPD or signs of renal failure possible
- Anorexia, inappetance
- Sudden death in pigs
Discuss the diagnosis of a UTI
Urinalysis: cysto if poss
- Dipstick: blood, WBC, alkaline pH (but not always)
- Urine sediment: large no.s of WBCs, bacteriuria
- Urine culture: definitive diagnosis, ideally prior to treatment
- Antimicrobial sensitivity: ideal, but not always practical
Blood tests and imaging not so useful inless ruling out upper UTI
- may or may not see signs of inflammation on haematology, may see evidence of renal compromise
- Ultrasonography good for identifying pyelonephritis
Microbial identification
- Not generally performed
- MaldiTof may become more common
Outline the basic approach treatment of UTIs
- Generally empirical therapy first (impractical to wait for results)
- Empirical: TMPS, Beta lactams, fluoroquinolones
- 7-14 day course for uncomplicated UTIs, 4-6 weeks if complicated (pyelonephritis, prostatitis, recurrent)
- C+S at end before stopping
Discuss the advantages and disadvantages of using TMPS for treatment of a UTI
- AD: good prostate penetration, achieves high concentrations in urine, cheap
- Disad: crystals form in kidney if animal poorly hydrated/renal function compromised, immune mediate hypersensitivity reactions in Dobermann
Discuss the advantages and disadvantages of using betalactams for the treatment of a UTI
- Ad: amoxyclav effective against most bacteria, good first line in most cases
- Disad: widespread resistance in some areas, potential for penicillin allergy, not for use in hind-gut fermenters e.g. guinea pigs
Discuss the use of fluoroquinolones for the treatment of a UTI
- Good penetration, may be first choice in entire males
- But critically important in humans, avoid use where possible
- May have effects on tendons, cartilage, CNS
What antibiotics are most appropriate for empirical treatment of these scenarios? A: cystitis in a dog B: FLUTD C: prostatitis D: pyelonephritis
A: Amoxyclav, TMPS
B: None - usually not needed
C: TMPS, fluoroquinolones
D TMPS, fluroquinolones, amoxyclav
What are the main causes of recurrent UTIs?
- Failure of initial therapy e.g. discontinued too early, antibiotic resistance
- Re-infection (predisposing causes e.g. immunosuppression, anatomical abnormality)
- Involvement of upper urinary tract
Outline your approach to a recurrent UTI
- C+S
- Assess for upper tract involvement: definitive rule out requires urine collection from ureter/renal pelvis, but may be seen on ultrasound as dilated renal pelvis, or on bloods as renal compromise
- Follow therapy with C+S to assess success, must be negative before stopping
- Consider nephrectomy if only one affected
Discuss the use of urinary acidification for the treatment of UTIs
- Urease producing bacteria alkalinise urine
- Unclear as tobenefit of acidification
- Common in humans: ammonium chloride, vit C, cranberry juice
- Best bet is to ensure adequate hydration (avoid diuresis with drugs, may predispose to infection)
Discuss potassium supplementation in cats and dogs and give examples of products
- Oral or IV possible
- IV: potassium chloride to IV fluids, must be well mixed and clearly labelled, do not infuse faster than 0.5mmol/kg/hr, monitor continuously with ECG
- Oral: Ipakitine, Kaminox, safe if eating or feeding tube in place
Outline hypokalaemic nephropathy
HypoK leads to impaired responsiveness to ADH, leads to PU and further renal losses
At what level is hyperkalaemia a cause for great concern
- When ECG abnormalities are evident
- Or >6.5mmol/l (normal range 3.5-5.5mmol/l)
- Myocardial toxicity occurs at 7.5mmol/l
Outline the treatment of hyperkalaemia
- IV calcium gluconate (0.5-1.5ml/kg 10% soln over 5-10 mins)
- Regular soluble insulin with dextrose
- Sodium bicarb (rarely, only if acid base can be monitored)
- Terbutaline (stimulates NaK ATPase to translocate K+ intracellularly_
Outline the treatment of hyperphosphataemia
- Diet most effective way of controlling increased phosphate in CRF patients.
- Calcitriol can be used once hyperphosphataemia has been resolved to help reduce PTH
What is the mechanism of action of benazepril hydrochloride?
- ACE inhibitor, blocks effects of angiotensin II and aldosterone
- Prevents vasoconstrition, retention of sodium and water and remodelling effects in kidney
- Normalises glomerular capillary pressure and reduces systemic blood pressure
Outline the initial approach to NSAID intoxication
- Assess cardiovascular function
- Take blood sample for haem and biochem (assess potassium status)
- IVFT (0.9% NaCl)
- Ideally urinary catheter to accurately measure urine output
- Monitor blood pressure
- If olig/anuric consider diuretics (mannitol, loop diuretics e.g. furosemide)
Outline some complications and contraindications that may occur as a result of diuretic use in an anuric/oliguric patient
- Mannitol: may result in hyponatraemia, care in patients with electrolyte abnormalities. Contraindications include intracellular dehydration, hypovolaemia
What are the main causes of urinary incontinence in adult bitches?
- USMI
- Detrusor instability
- Vaginal pooling
- Lower UTI
- Neurogenic disorders
What are the main causes of urinary incontinence in adult male dogs?
- Prostatic disease
- USMI
- Detrusor instability
- Neurogenic disorders
What are the main causes of urinary incontinence in juvenile dogs?
- Ectopic ureter
- Urethral or bladder hypoplasia
- Congenital USMI
- Vaginal anomalies
- Intersex disorder
- Patent urachus
What are the main causes of urinary incontinence in cats?
- USMI
- Overflow
- Neurogenic disorders
- FeLV associated
Identify the neurogenic causes of urinary incontinence
- Sacral fracture
- Pelvic nerve/plexus trauma
- Lumbosacral disease e.g. IVDD, lumbosacral stenosis, neoplasia
- Sacral malformation (Manx cat)
- FeLV associated
- Generalised peripheral lower motor neuron disease
- Dysautonomia
Identify non-neurogenic causes of urinary incontinence
- USMI
- Urethral hypoplasia
- Lower urinary tract inflammation
- Detrusor instability
- Ectopic ureter
- Partial outflow obstruction e.g. uroliths, neoplasia, polyps
- Patent urachus
- Vestibulovaginal stenosis/septumm
- Primary detrusor atony with overflow
What are the 2 treatment options for urinary sphincter mechanism incompetence?
- Sympathomimetics (phenylpropanolamine e.g. propalin, urilin)
- Oestrogens (estriol e.g. incurin)
Outline the mechanism of action of sympathomimetics for the treatment of USMI
Increases stimulation of alpha-adrenergic receptors to improve urethral tone
Outline the indications and contraindications for sympathomimetics for the treatment of USMI
- Indications: males or females, dogs or cats, poor response to oestrogen
- Contra: hypertension, some cardiac diseases, anxiety disoders
Give the administration frequency and residual effect duration of sympathomimetics used for the treatment of USMI
- Administer q4-24 hours
- Short residual effects
Outline the adverse effects of sympathomimetics used for the treatment of USMI
- Hyperactivity
- Hypertension
- Anxiety
- Tachycardia
- Anorexia
- Weight loss
Compare the effectiveness of sympathomimetics and oestrogens for the treatment of USMI
Sympatho 75-90% excellent results, oestrogens 40-65% excellent results
Can be used together
Describe the mechanism of action of oestrogens for the treatment of USMI
Sensitise alpha adrenoceptors to adrenaline and result in better closure pressure of sphincter
Give the indications and contraindications for oestrogens for the treatment of USMI
- Indications: bitches, combination with alpha-agonists, recurrent UTI or vaginitis
- Contra: males dogs, intact bitches, cats, pregnancy
Give the administration frequency and residual effect duration of oestrogens used for the treatment of USMI
- Q2-14 days
- Residual effects possibly prolonged
Outline the adverse effects of oestrogens used for the treatment of USMI
- Behavioural change
- Bone marrow toxicity (rare)
- Oestrus
- Exacerbation of immune mediated disease
What are sweet or fishy odours in urine indicative of?
- Fishy: bacterial infection
- Sweet: ketones (diabetes mellitus or ketosis)
What may cause falsely positive protein results on urinalysis?
Contamination of sample with alkaline cleaning products, or alkaline urine
How many erythrocytes, leucocytes and epithelial cells are considered normal on urine sediment examination from a cysto sample?
- Eryth: 0-3/hpf
- Leuco: 0-3/hpf
- Epith: small numbers normal
How many casts are considered normal on urine sediment examination from a cysto sample?
Small number of hyaline (-2/hpf) and granular (0-1/hpf) is normal
Briefly describe the formation of urinary casts and how these may occur abnormally
- Formed by protein or cellular deposits in the renal tubules, dissolve in alkaline urine
- Large numbers indicate renal tubule disease
Briefly describe struvite crystals incl. composition and appearance
- Normal: occasionally seen in cold, concentrated alkaline urine
- magnesium ammonoium phosphate
- 3-8 sided prisms, often look like coffin lids
Briefly describe cacium oxalate crystals incl. appearance and cause
- Found in acidic or neutral urine, small no. normal in dogs and horses
- Dihydrate: small squares with an X
- Monohydrate: long rectangular, or dumbbell shaped
- Large no. indicate ethylene glycol toxicosis
In which species are calcium carbonate crystals normally found and describe their appearance
- Normal in horse and rabbit
- Round or granular
Describe the appearance of urates/uric acid crysals
- Urates: brown/yellow coloured spheres or amorphous structures
- Uric acid: diamond shapes
Describe the appearance of cystine crystals
Flat colourless hexagons, presence indicates genetic defect in renal cystine handling
Describe the appearance of sulphonamide crystals
- Often needle shaped dark crystals, can take various shapes
- Found in animals treated with sulphonamide
What radiographic finding is typical for FIP and multicentric neoplasia?
A hypoechoic marginal band around the kidney
Compare the radiographic features of a bladder polyp vs a mucosal tumour
Polyp often more homogenous, hyperechoic and relatively narrow base
Define periuria
Urination at inappropriate locations
List the key differentials for dysuria in a small animal
- Inflammation of LUT or genital tract
- Infection resulting in inflammation
- Narrowing/obstruction of urethra (physical or functional)
What anatomical sites and possible causes should be considered where haematuria is identified in a small animal?
- Renal: trauma, neoplasia, calculi idiopathic
- Post-renal: inflammation, infection, calculi, neoplasia, iatrogenic
- Genital: oestrus, prostate disease
How may the source of blood in urine be identified?
- Timing of blood in stream
- Appears at the end: prostatic origin
- Appears early on: urethral
Compare the appearance of haematuria, haemoglobinuria and myoglobinuria
- Haematuria: when spun, supernatant is clear
- Haemoglobin: when spun, the plasma is pink
- Myoglobin: red/brown urine
List the possible causes of haemoglobinuria in small animals and how these can be differentiated
- Pre rena: intravascular haemolysiss e.g. IMHA
- Post-renal: haemolysis in hypotonic urine (blood plasma may be normal)
List the possible causes of myoglobinuria in small animals, and give the appearance of spun blood and urine
Systemic disease causing extensive muscle destruction e.g. ischaemic necrosis, rare in small animals
- Urine: coloured supernatant
- Blood: plasma clear
Compare lower urinary tract neoplasia in dogs, horses and ruminants
- Dogs: 90% are TCC, westies, scotties, shelties predisposed
- Horses: SCC most common in bladder, also sarcoids of urethra, external genital tract, sheath
- Ruminants: acute bracken poisoning
What conditions do UTIs commonly occur secondary to?
- Systemic disease leading to low USG e.g. hyperT4 in cats
- Anatomic defects e.g. ectopic ureters
- Urinary calculi
- Neoplasia
What obstructive causes may lead to dysuria in small animals?
- Urinary calculi
- Neoplasia
- Urethral plugs
- Rupture
List the most common uroliths seen in dogs and cats and when these occur
- Struvite (magnesium ammonium phosphate)
- Calcium oxalate (dihydrate assocaited with hpercalcaemia, monohydrate with ethylene glycol)
- Ammonium biurate in dogs with PSS, of normal Dalmatians and Bulldogs
- Cystine
Outline the relationship between UTIs and urolith formatioin
- Lead to loss of inhibitors
- Urine more alkaline due to urease organisms often
Describe the clinical signs of nephroliths
- Asymptomatic, may be incidental finding on radiograph
- May be associated with pyelonephritis: pain, pyuria, pyrexia
Describe the clinical signs of ureteroliths
- Asymptomatic, incidental finding on radiograph
- May have pyelonephritis: pain, pyuria, pyrexia
- Renemegaly may develop, uni or bi latera +/- pain
- Renal failure if bilateral: acute bilateral hydronephrosis
Describe the clinical signs of cystoliths
- True LUT signs: dysuria, pollakiuria, haematuria
- rarely palpable on physical exam
- Abdominal discomfort
- Licking at penis/vulva
- urethral obstruction leading to post-renal azotaemia, AKI
Which calculi are radiopaque?
- Struvite
- Calcium oxalate
- Calcium phosphate
Which calculi are radiolucent and how are they diagnosed?
- Urates
- Cystine
- Require +ve contrast radiography
Evaluate the use of abdominal ultrasound for the diagnosis of uroliths
- Not useful for urethra, only see abdominal portion
- Easy to miss a stone
- Look for hydronephrosis and proximal ureter in cas
List the methods that can be used to collect a urolith
- Voiding urohydropulsion (if not too big)
- Catheter assisted retrieval (suck onto end of catheter)
- Cystoscopy
- Cystotomy (therapeutic and diagnostic)
- Urethrotomy/urethrostomy (if required to relieve obstruction)
Outline the treatment of nephroliths
- Only need treating if problematic
- Dissolution diets for struvite, manage UTI
- Support kidneys if needed
- Renal surgery not a good idea
- May be best to leave alone
Outline the treatment of ureteroliths
- Prompt referral
- Surgery/stenting: ureteric stenting, subcut ureteral bypass or lithotripsy used
Outline the treatment options for cystoliths
- Medical dissolution diets
- Voiding urohydropulseion
- Cystoscopy
- Cystotomy
- Laser lithotripsy
Outline the treatment of urethral obstruction
- Treat as emergency
- Stabilise patient, manage hyperK, fluid therapy
- Decompress bladder vital
- Retrograde urohydropulsion and treat as for cystolith if possible
- Urethrotomy/urethrostomy if nothing else works and patient stable, best if urethra not oedematous/swollen
What are the indications for medical treatment of uroliths?
- Non-obstructive dsiease
- Struvite, cystine and urate stones
Outline the general principles of medical management of uroliths
- Increase water intake
- Manipulate urine pH appropriate to the urolith identified
- Decrease concentration of mineral components in the urine
- Treat for 1 mo after radiograph shows resolution
- Manage underlying cause where appopriate (e.g. UTI in dogs)
Discuss the management of calcium stones in small animals
- Most renal/ureteric stones contain calcium
- No suitable means of dissolution
- Little information re. management, specific diet may help (may occur as a result of acidifying diets)
Describe the pathological changes that are seen on PM and histopath in the kidney due to lepto in a dog
- Chronic interstitial nephritis, severe fibrosis and tubular atrophy
- Inflammatory cell infiltrate
- Grossly see depressed multifocal coalescing tan areas in the kidney, some extending into the medulla
Describe urethral plugs in cats
- Protein colloid matrix made up of mucoproteins, albumin, globulin, cells, blood clots +/- crystalline material
- Can cause obstruction esp. in males
Outline the clinical signs of FLUTD
- Dysuria
- Pollakiurria
- Haematuria
- Stranguria
- Periuria
- Signs of urethral obstruction
- Behavioural changes e.g. loss of house training, aggression, excessive grooming,
- Constipation
- Stilted gait
- Abdominal pain
Describe the typical signalment for FLUTD
- Young -middle ages (generally <10yo)
- Overweight
- Inactive
- Mainly indoor
- Dry food diet
- Multicat household
Describe the pathophysiology of FLUTD
- Interstitial cystitis
- Neurogenic inflammation with chronic pain: vasodilation, vascular leakage, absence of mononuclear or neutrophilic infiltrate, increase mast cells
- Neuroendocrine imbalance: may be combined with neurogenic inflammation, impaired ability to deal with stress (lack of -ve feedback)
- Urine exacerbates inflammation
- leads to bladder hyperirritability, altered GAG layer, pain, swelling
Outline your approach to the diagnosis of FLUTD
- Signalment, look for underlying causes
- History: often recurrent, other features that may increase likely hood e.g. UTI, neoplasia, urolith
- Physical examination: obstructed or non-obstructed?
- Blood haematology and biochem:
- Urinalysis: esp. sediment, rule out other causes of disease
- Radiography and ultrasonography
What signs may indicate that a cat has a urinary tract obstruction?
- Bladder: distended or small tense bladder, firm, painful
- Penis may be discoloured and swollen
- Dehydrated
Outline the typical management of a non-obstructed cat with FLUTD
Generally just leave and clinical signs subside within 5-7days without treatment, but must warn re. signs of obstruction
In a non-obstructed cat where you suspect FLUTD, what other conditions must be ruled out and in what order?
- Infection
- Uroliths
- Neoplasia
Discuss the use of diagnostic imaging when investigating a cat with suspected FLUTD
- Radiography better, look for calculi, assess bladder wall thickness/integrity with contrast.
- Identification of urethra abnormalities e.g. stricture, urolithiasis, rupture on contrast radiography
- Double contrast best for calculi
- Ultrasonography good for bladder structure, identification of masses
Discuss the use of blood biochem and haematology in the investigation of a cat you suspect has FLUTD
- Look for concurrent disease e.g. CKD, DM, hyperT4
- Consequences e.g. Fe deficiency anaemia with chronic bleeding tumour
- Underlying cause for uroliths e.g. hypercalcaemia, PSS
Describe the clinical signs of urethral obstruction that may occur with FLUTD
- Anorexia
- Vomiting
- Depression
- Circulatory shock
Explain the development of obstructions with FLUTD
- Urethral calculi may form
- Functional obstruction from mucosal oedema, urethral spasm (neurogenic)
- May occur as a result of inflammation
- Formation of urethral plug (esp. male cats)
Outline the procedure for unblocking a male cat
- Stabilise with IVFT manage hyperkalaemia
- Sedate/GA (GA allows better analgesia)
- Cystocentesis to relieve back pressure
- Extrude penis and massage gently in order to massage out any plug material
- Straighten the urethra
- Insert catheter and flush with saline as catheter is advanced-
- Rectal palpation during retrograde hydropulsion helps
Discuss the prognosis for FLUTD
- Recurrence in 35-65% of cats with within 1-2 years of initial event
- Some cats develop chronic persistent signs for weeks or months
Outline the emergency treatment of a cat with FLUTD
- Stabilise patient
- Identify obstruction or bladder rupture and manage this
- Manage stress
- Buprenorphine shown best for pain relief in these cases
- Flush bladder up to urohydrodistension
Outline the long term management and prevention of FLUTD
- Increase water intake
- Avoid/mitigate stress e.g. multicat households
- Consider pheromones to reduce stress, environmental enrichment
- Glycosaminoglycans
- Anxiolytics suggested
- Muscle relaxants
Discuss the use of GAGs in the management of FLUTD
- Protect bladder lining
- E.g. N-acetyl glucosamine, GAG precursor
- No beneficial overall effect in controlled trial
Discuss the use of anxiolytics in the management of FLUTF
- E.g. amitriptyline
- tricyclic antidepressant, anticholinergic, antihistaminic, anti-inflammatoyr, analgesic
- Helpful in women, but controversial in cats due to side effects
- Likely just sedates cat