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)