Dogs and Cats 21 Flashcards
renal proteinuria what are the main types, causes and how to know
- transient
- Persistent renal proteinuria and other urinalysis results
○ Glomerular disease
§ Often marked proteinuria (UPC> 2.0)
○ Tubular disease
§ Possibly also glucosuria, acidosis, electrolyte imbalances
When to suspect glomerulopathes and the histopathological classification
When to suspect glomerulopathies
- Persistent renal proteinuria (UPC elevation)
- Hypoalbuminaemia
- Hypercholesterolaemia
- Persistent hypertension
- Low USG without explanation
- Normal USG but azotaemia in a hydrated animal - uncommon
Histopathological classification: glomerular disease
- Examples of subgroups recognized are:
○ Membranoproliferative glomerulonephritis - more common in dogs
○ Membranous nephropathy
○ Amyloidosis - more common especially in cats
Glomerular disease primary and secondary causes
- Primary ○ Familial congenital - Secondary ○ Infectious ○ Immune-mediated ○ Idiopathic ○ Neoplastic ○ Miscellaneous
Familial renal disease suspicion and approach
- Suspect familial renal disease if
○ Pet is purebred - sharpies, British shorthair
○ Pet is adolescent or young adult
○ Siblings/close relatives are showing similar signs - Approach
○ Screening tests (breed associations)
○ Search genetic disease database;
Secondary glomerulopathies what are the 4 main causes
- Caused by infection
○ Dogs: bacteria causing pyelonephritis, prostatitis, orchitis - Caused by inflammation
○ Dermatitis, periodontal disease, SLE - Caused by neoplasia
○ Lymphoma, mastocytosis or histiocytic disease - Miscellaneous causes
○ Overvaccination, Trimethoprim sulfonamide
Glomerulopathies investigation what does it involve
- Different degree of work-up depending on patient criteria
- Patients are categorised in 3 tiers according to:
○ Persistent renal proteinuria
○ Hypoalbuminaemia
○ Azotaemia
○ Hypertension and sequelae
What are the potential diagnostic tests for a glomerulopathy and when is work up indicated
- Tests ○ Renal biopsy ○ Genetic tests ○ Antithrombin III measurement ○ Abdominal ultrasound, thoracic radiographs ○ Haematology, Biochemistry(Serology) ○ Blood pressure ○ Urinalysis, UPC, Culture - Tests may be essential, recommended or potentially helpful - If indicated, work up for: ○ Hypoalbuminaemia ○ Azotaemia ○ Hypertension ○ Infectious diseases ○ Other sequelae
when to do a renal biopsy and when not to
- Do it (well prepared): ○ Disease unresponsive to standard care ○ Severe proteinuria (UPC > 3.5) ○ No overt contraindications - Leave it: ○ IRIS stage 4 renal disease ○ Biopsy unlikely to change treatment plan ○ Contraindications
Nephrotic syndrome what is it a combination of and indication of
- Combination of
○ Hypoalbuminaemia
○ Hypercholesterolaemia
○ Proteinuria
○ Extracellular fluid accumulation (e.g. ascites) - Indicator of severe disease and associated with poor prognosis
Treatment of glomerular disease what are the main factors that need to be managed
- Factors to be managed
○ Protein loss
§ Weight loss, hypercoagulability, hypercholesterolaemia, ascites
○ Underlying disease
§ Inflammation, immune-complex deposition
○ Progression of renal disease
§ Hypertension, azotaemia - Management may be supportive, or specifically targeting the underlying disease
What are the 4 main things involved in treatment of glomerular disease
1) Supportive management of blood pressure and proteinuria
2) further supportive treatment
3) further supportive treatment in selected patients
4) specific treatment = treat underlying disease and or immunosuppressive treatment
Supportive management of blood pressure and proteinuria in the treatment of glomerular disease what drugs involved and what do they do
○ ACE-inhibitor, e.g. benazepril
§ Less filtration pressure in glomerulus due to vasodilation of efferent arteriole
§ May cause reduction in renal blood flow and GFR - RISK
□ Monitoring of renal function after start
○ Further blood pressure control
§ Calcium channel blocker, e.g. amlodipine
§ Angiotensin receptor blocker, e.g. Telmisartan
Further supportive treatments in teh treatment of glomerular disease what are the 2 main things involved and what else need to do
○ Protein-restricted diet
§ O3 fatty acid supplement - anti-inflammatory as well
○ Anticoagulants
§ Antithrombin III - if albumin is lost this is lost as well
□ If lose hypercoagulable -> predispose to blood cot
§ Aspirin or Clopidogrel
○ Stage and treat azotaemic dogs/cats
What are the 3 main further supprotive treatments that may be needed in treating glomerular disease in selected patients
1) Drainage of ascites
§ Only recommended in cases with ascites causing respiratory distress
2) Diuretics
§ Only recommended in selected cases with ascites
§ Potassium sparing ones - spirolactone
3) IV fluid therapy
§ Crystalloids: avoid fluid overload
§ Colloids: Only in patients with hypotension that does not respond to crystalloids
Specific treatment (treating underlying disease or immunosuppresives) for glomerular disease when to do
○ Immunosuppressive treatment –yes or no?
§ In 50% of dogs, glomerulopathies are associated with immune-complex deposition
§ Possible benefit for Immunosuppressives
§ Immunosuppressives are not indicated in all dogs, e.g.
□ No benefit in many genetic disorders
□ No benefit in amyloidosis
Specific treatment (treating underlying disease or immunosuppresives) for glomerular disease current treatment guidelines
§ Depend progression of disease § Rapid □ Prednisolone and/or □ Mycophenolate mofetil, or □ Cyclophosphamide § Slow - in addition to above □ Azathioprine □ Cyclosporine □ Chlorambucil
What are the 5 main treatment goals in treating glomerular disease and treat same for dog and cats?
- UPC:WNL or at least 50% reduction of UPC
- Blood pressure controlled
- No hyperkalaemia
- Stabilise azotaemia
- No sequelae
Cats are not dogs
- Causes of glomerulonephritis are less well established in cats.
- Very limited studies about therapy in cats.
- Thus, specific treatment guidelines are for DOGS ONLY.
Monitoring glomerular disease what frequency and what monitoring
- 1 week –1 month –3 months
- Appetite, Urination
- Physical components
○ Body weight, BCS
○ Physical examination changes - Blood pressure
- Clinicopathological
○ UA and UPC, +-Ucult
○ PO4, K, Na, Ca, urea, crea, cholesterol, albumin, CBC
Prognosis for glomerular disease
- Regression is possible
- Poor prognostic indicators:
○ Azotaemia (10-45 days median survival)
○ Nephrotic syndrome (51 d vs 605 d median survival) - Although MST with NS is short, survival >7 years has been reported
What is the blood supple and lymphatic drainage from the bladder
- Caudal vesicular artery: ○ Major supply § Arises from uterine(female )or prostatic (male) branches of the internal pudendal - Cranial vesicular artery: ○ Terminal end of umbilical ○ Supplies cranial end of bladder. - Venous drainage: internal pudendal veins. - Lymphatic drainage: ○ Hypogastric ○ Sublumbar ○ Medial iliac lymph nodes
Bladder innervation what are the 3 main ones and the function
- α adrenergic receptors in the smooth muscle of the bladder neck and urethra
1) Sympathetic innervation
○ Hypogastric nerves(L4-L6)
○ Storage (filling): detrusor relaxation & bladder neck/ urethral contraction - MAINTAIN CONTINENCE
2) Parasympathetic innervation
○ Pelvic & Pudendal nerves(S1-S3)
○ Voiding: detrusor contraction, relaxation of the bladder neck & urethra
3) Somatic innervation: -
○ Pudendal nerve(S1-S3)
○ Voluntary control of urination
Storage stage of the bladder what innervation and function is involved
- Smooth mm at vesicular-uretheral junction maintained in contraction for storage (Except during micturition):
○ Mediated by α-adrenergic stimulation via the hypogastric nerve
○ B-receptor stimulation via the hypogastric nerve relaxes the detrusor simultaneously
Voiding of the bladder what innervation and function is involved
- As bladder nears capacity, stretch receptors are activated:
- Results in parasympathetic stimulus to institute reflex micturition
- Depresses sympathetic outflow in the Hypogastric n and brainstem (pons-micturition centre)
- Parasympathetic nerve supply originates in pontine centre and in the sacral spinal cord(S1-3):
- Stimulates and maintains detrusor contraction via the Pelvic nerve
Urethral anatomy where extends and anatomy in male dog and cat
- Extends from the trigone to the urethral meatus
- Lined by transitional epithelium
- Male dog
○ Preprostatic
○ Prostatic (within prostate)
○ Membranous/cavernous
○ Smooth muscle
§ Longitudinal, runs length of the urethra
○ Straited muscle - distal 2/3rds - Male cat
○ More distinct preprostatic urethra
○ Short prostatic section
○ Membranous (within pelvis)
Urethral anatomy in female dogs and cats
- Female dogs
○ Urethra shorter and wider
○ Smooth muscle: outer and inner longitudinal and middle circular, runs length of urethra
○ Straited muscle: distal 1/3
○ OHE increases collagen and decreases smooth muscle in the proximal urethra - PREDISPOSE - Female cats
○ C/w female dogs
§ Lumen smaller
§ Less circular smooth muscle and elastic fibres
Blood supply and innervation to the urethral in male and female
Blood supply - Female ○ Vaginal arteries from the urogenital artery - Male ○ Prostatic: prostatic artery ○ Membranous/cavernous: urethral branches of pudendal, urethral or prostatic, urethral bulb artery Innervation - Striated muscle ○ External urethral sphincter ○ Pudendal nerve - Smooth muscle ○ Internal urethral sphincter ○ Parasympathetic: pelvic nerve ○ Sympathetic: (alpha adrenergic) hypogastric nerve
Healing of the bladder, how long does it take
- Bladder undergoes rapid healing
○ Mucosal defects heal within 5 days
○ Full thickness incisions regain 100% normal tissue strength in 14-21 days
what are the 7 main indications for bladder surgery
- Urolithiasis
- Trauma
- Neoplasia
- Ectopic ureter surgery
- Urachal diverticulum
- Bladder biopsy
- Urinary diversion - cystotomy tubes
Cystotomy what is it and what need to do in preparation -EXAM
- Midline celiotomy -> if removing uroliths than caudal laparotomy is appropriate
Preparation - Stay sutures
○ In the apex of the bladder (cranial traction)
○ Lateral to the incision - Pack off the bladder - moistened lap sponges - CLEAN CONTAMINATED SURGERY
- Empty the bladder
○ Catheter
○ Cystocentesis/suction
○ Empty bladder after incision via suction
Cystotmy what are the 2 main approaches, which better and how to open bladder -EXAM
○ Dorsal or ventral approach
§ No issues with adhesions
§ Ventral approach
□ Improved exposure of trigone (visualisation of ureteral orifices)
□ Decrease risk of iatrogenic urethral damage than dorsal approach
□ Avoids retroflexion and 180 degree kinking of urethra than dorsal
○ Choose avascular region in ventral midline
○ Stab incision with 15 or 11 blade
○ Extend with Metzenbaum scissors
○ Make incision from apex to trigone region
Cystotomy closure suture material and what is important
○ Rapid healing occurs with mucosal defects epithelialize in < 5days
○ Accurate needle placement through the submucosa is the most important aspect of closure
○ Suture material
- synthetic monofilament absorbable (PDS 3/0-5/0)
- simple continuous or interrupted
§ Ideally do NOT penetrate lumen
§ Engage submucosa only: - NO KNOTS WITHIN LUMEN
What is important to consider with closing bladder and synthetic sutures and which types degrade with what
□ Absorbed via hydrolysis
® Hydrolysis is more rapid in urine, particularly when infected
® Sutures with a glycolide component degrade more rapidly in a ALKALINE environment (when infected)
® Sutures with dioxanone component degrade more rapidly in an acid environment
® Short acting absorbable may not last long enough for healing infected urine
Urteral ectopia what are the 2 main types which species common in and what does this influence
Morphologic types
1. Intramural
○ Ureter enter bladder wall at a normal location
○ Runs sub-mucosal empty into the urogenital tract distal to the trigone
○ Most common form in dogs
2. Extramural
○ Ureter by-passes bladder completely
○ Inserts distal to the trigone
○ Most common form in cats
- Morphology influences method of correction
Surgical correction for intra-mural ectopic ureters what are the 2 main options and which recommended
1) Neourecterostomy - create a new opening - SPECIALIST LEVEL SURGERY
2) Cystoscopic-guided LASER ablation - RECOMMENDED - more minimally invasive
§ Catheterise the ureter and laser the section away
What is the surgical correction for extra-mural ectopic ureters and how occur
○ Ureteroneocystostomy
§ Re-implantation of the ureter from the abnormal insertion point into the bladder lumen proximal to the trigone
□ Difficult due to small size of ureters
§ Ventral cystotomy
§ Stab incision
§ Passage of ureter through bladder wall
§ Spatulation
§ Suturing with 5/0 - 6/0 suture
Surgical outcome of ectopic ureter surgical and what need to do
- Persistent incontinence is common
○ 30-70%
○ Concomitant functional bladder/urethral abnormalities (huskies)
○ USMI
○ Urethral pressure profilometry pre-op may be predictive (where available)
○ Address this problem at index surgery
○ Communicate and discuss with owners beforehand
Urethral sphincter mechanism incompetence predisposing factors
- Urethral tone
- Bladder neck position - if intrapelvic bladders
- Urethral length
- Neuter status
- Body size
- Breed
- Tail docking
- Obesity
Urethral sphincter mechanism incompetence surgical treatment when used what are the 3 main things targeting and techniques used
only if adverse effects or refractory to medical management
Surgical targeting ->
1) bladder neck position -> advance bladder neck into abdominal pressure zone
§ Use colposuspension or urethrocystopexy/urethropexy
2) Increase functional length of the urethra
§ Colposuspension
§ Urethral lengthening
§ Urethrocytstopexy/ urethropexy
3) Increase static resistance via reduction in urethral diameter - what we are moving towards
§ Submucosal injections
§ Artificial urethral sphincters (AUS)
What are the 3 main surgical treatments for urethral sphincter mechanism incompetence
1) colposuspensio
2) endoscopic transmucosal infection - good
3) hydraulic occlusion - good
Colposuspension what is it used for, what is involved and outcomes
Urethral sphincter mechanism incompetence surgical treatment
§ Sutures vaginal tissue to pubic brim which -> creates sling to put pressure on urethra
□ Advances bladder neck and proximal urethra into abdominal pressure zone
□ Increases functional urethra length
□ Compression of urethra between vagina and pubis
§ Outcomes
□ Cure 54%, improvement 36%, fail 9%
□ Complications 15%
® Dyssunergia
® Infection
® Recurrence - suture breakdown
® May require adjuvant medical
