Urinary Tract Disease Flashcards
Functions of the Urinary Tract
Filters waste from the blood and excretes it as urine.
Maintains extracellular fluid (ECF) balance in the body.
Balances nutrients. I.e. Minerals.
Produces the hormone erythropoietin which stimulates the bone marrow to produce red blood cells.
Nephritis
Inflamation of the kidneys
Glomerulonephritis
Glomerulonephritis, also known as glomerular nephritis (GN), refers to inflammation of the glomeruli (individual units within the kidneys that filter the blood) – they may become inflamed for various reasons and if prolonged this can lead to CKD
Pyelonephritis
A bacterial infection of the kidneys, which are part of the upper urinary tract. Infection is more common in middle-aged or older dogs. Often pyelonephritis starts from bacteria in the bladder that spread upwards to the kidneys.
Interstitial nephritis
Interstitial nephritis is a kidney disorder in which the spaces between the kidney tubules become swollen (inflamed).
Can be chronic or acute, whihc can be caused by side effects of certain drugs.
Renal insufficiency
damaged kidney can still process waste, clinical signs not yet evident.
Renal failure
damage increases to point where waste cannot be processed (~75% nephrons damaged), clinical signs become apparent.
What happens in the diseased Kidney?
Decreased renal function interfering with the kidneys ability to maintain fluid and electrolyte homeostasis.
Decrease in the ability to concentrate urine early on.
GFR
Glomerular Filtration Rate
Azotaemia (Uraemia)
Increase of nitrogenous waste products, creatinine and urea (BUN).
What can Azotaemia (Uraemia) be classed as?
Pre-Renal – Dehydration, shock.
Renal – Nephrotoxins, glomerulonephritis
Post-Renal – Urinary obstruction, trauma.
- % of kidney function needs to be lost before urea and creatinine levels raise to significant levels to be detected in bloods
70%
AKD
Acute kidney disease
ARF
Acute renal failure
CKD
Chronic kidney disease
CRF
Chronic renal failure
Aetiology: Acute Kidney Disease
Reduced blood flow to the kidneys.
Cell damage of the kidneys.
Post-renal obstruction.
Acute exacerbation of chronic renal failure.
Clinical Signs: Acute Renal Failure
Sudden onset:
Anorexia
Lethargy
Depression
Oliguria/Anuria -> Polyuria
Vomiting
Diarrhoea
Polydipsia
Dehydration
Uraemic breath
Diagnosis: Acute Renal Failure
Blood test: Haematology and biochemistry.
Urinalysis: Specific gravity, dipstick and sediment examination.
Radiography
Ultrasonography
Treatment: Acute Renal Failure
Treatment of the underlying cause - often not possible to treat the actual disease
Mainly supportive:
Fluid therapy
Diuretics – Frusemide
Antiemetics
Dialysis
Aetiology: Chronic Kidney Disease
Once kidneys are no longer able to compensate the animal presents with signs of renal failure.
Idiopathic deterioration in geriatric cats – most common.
Acute renal failure i.e. injury or toxin
Pyelonephritis
Glomerulonephritis
Congenital/hereditary disease – polycystic kidney disease
Concurrent condition – Diabetes mellitus, hypertension.
Pathophysiology: Chronic Renal Failure
The kidney is unable to filter nitrogenous waste from the blood leading to uraemia
Deterioration in renal function causes pH and electrolyte imbalance (potassium and phosphate)
Reduced production of erythropoietin leads to reduced erythrocyte formation in the bone marrow
When do signs of renal failure appear?
Reserve capacity of kidneys means signs of renal failure only appear when 2/3-3/4 of functioning tissue is lost
Clinical Signs: Chronic Kidney Disease
Polyuria Polydipsia Depression
Oral ulcers Halitosis Seizures
Anaemia Anuric Vomiting
Inappetence/Anorexia Dehydration
Weight loss
Diagnosis: Chronic Kidney Disease
History
Clinical signs
Physical examination
Urinalysis – Specific gravity/dipstick.
Blood test
Blood pressure
Radiography
Ultrasound
Determine cause and extent of azotaemia
CKD Diagnosis: Blood Tests
Elevation in urea and creatinine in plasma.
Check electrolytes.
SDMA testing.
SDMA blood testing
Symmetrical Dimethylarginine (SDMA)
CKD- Diagnosis: Urinalysis
Urine specific gravity. Less than 1.035 is suggestive.
Identifies loss of concentrating ability.
Declining USG raises suspicions.
Urine protein levels
Presence of blood and infection should be ruled out.
CKD - Kidney Staging:
International renal interest society. (IRIS)
Stages 1 to 4.
Staging allows us to generate an appropriate treatment/monitoring plan for the patient.
Based on:
Creatinine - Needs to be repeated twice on different occasions.
Proteinuria
Blood pressure
CKD - Treatment
Fluid therapy.
Diet.
Drugs. i.e Antibiotics
Restriction of phosphate. i.e phosphate binders, potassium supplementation.
Managing hypertension. i.e. amlofipine
Anaemia. i.e. Nandralone, erythropoietin.
Monitor urine infections.
Manage anorexia and vomiting.
Aetioloy: Lower Urinary Tract Disease
Infection
Calculi/crystals
Neoplasia
Trauma
Iatrogenic
Neurogenic
Concurrent disease. i.e. Diabetes Mellitus
Idiopathic – Most common.
Iatrogenic
a potential complication of surgical procedures performed in or around the retroperitoneal abdominal space or pelvis.
Neurogenic
abnormal function of either the bladder, bladder neck, and/or its sphincters related to a neurologic disorder
Lower Urinary Tract Disease Clinical Signs:
Cystitis – pollakuria, dysuria, haematuria
Pain
Blockage – oliguria, anuria
Incontinence
Varying frequency/volume of urine
Abnormal micturition – weak and interrupted
Licking external genitalia
Depression
Vomiting
Anorexia
Dehydration
Urolithiasis – FLUTD
Affecting the lower urinary tract of the cat.
Can be multi-factor in origin.
FLUTD - meaning
Feline lower urinary tract disease.
Aetiology: FLUTD
Idiopathic cystitis.
Urolithiasis (stones)
Crystals (Urethral plug)
Infection – very rare.
Multicat household – Stress can trigger.
Underactive, overweight, neutered cats.
Pathophysiology: FLUTD
rritation/inflammation of the bladder wall/urethra.
May get recurrent bouts of cystitis.
Uroliths or urethral plugs may cause urinary obstruction – complete obstruction is an emergency!!
Trauma/iatrogenic damage may result in bladder wall dysfunction or rupture of the urinary tract.
Inability to void urine leads to azotaemia and signs associated with Acute Renal Failure (ARF)
FLUTD Diagnosis:
History
Clinical signs
Observation of micturition
Neurological examination
Urinalysis – Visual, dipstick, microscopy, culture, specific gravity
Radiography
Ultrasound
Bloods – Haematology and biochemistry.
FLUTD treatment-
Treat the cause.
Clear blockages:
Catheterisation
Sterile saline
Cystocentesis
Increase water intake.
Resolve any toileting problems. I.e. Litter trays.
Antibiotics, anti-inflammatories, analgesia
Diet modification
Phermones
