Congenital And Neonatal Abnormalities Flashcards
What is the normal embryolical development of the adult kidney? How can this lead to incontience?
Embryology we have a primitive bladder. Mesonephric duct – dont worry!
Just remember; as embryo develops there are three stages and the mesonephros is the 2nd stage.
Long term stages - Kidneys form and meet with the bladder from the ureteric bud
Mesonephric is form primitive mesonephors – most important for males! Some of these retain and form their sex organs.
Anything that goes wrong here e.g. trigone or ureter = presentation in the neonate!
If the ureteric buds don’t form in the right place can cause problems.
Where are congenital abnormalities usually seen?
Small animals
Why might we not see congenital problems until adults?
•some diseases are progressive and clinical signs are not seen until the animals is an adult
–Dysfunction which builds up over life
What shoudl you do if you suspect a congenital abnormality?
•Check breed related information and advise breeder accordingly
What are the 2 types of congenital abnormalities?
- Structural anomalies (something physically changed) e.g.
–Absence of kidney
–Glomerulopathy due to abnormal collagen in basement membrane
- Functional anomalies (going wrong in urogenesis leading to other problems to occur) e.g.
–Impaired tubular reabsorption in Basenjis
–Hyperuricuria in Dalmations
What are structural abnormalities?
•Related to problems during embryonic development
What are the 4 classifications of structural abormalites?
•Agenesis (don’t happen), hypoplasia (form at an impaired rate), dysplasia (don’t form as they should) and aplasia can affect any part of the urinary tract
What are clinical signs of structural abnormalities related to?
Structure affected
What is this?
Renal dyplasia
Name examples of structural abnormalities? (4)
•glomerulopathies, nephropathies, polycystic renal disease, amyloidosis
Which structural abnormality happens later in life and why is this?
–Some conditions are progressive -> late onset signs (e.g. 1-6 years for amyloidosis)
•Need enough time for the condition to occur and start affecting the animal
What is this? What is the problem with it?
Polycystic – cat;
Impair most of the kidney – animal
will be affected
What is this and where is it seen?
Pig - cyst - often seen at PM
What is this?
Dog cysts
What is this? What else can we use U/S for?
Renal Cysts
Could also look for structural changes, and then also biopsies.
What is a main structural abnormaility and what causes the main clinical signs?
•Glomerulopathy (mainly glomerulus affected). Primary problem with filtration! Things which should remain in the animal plasma will start to appear in the urine.
–Main clinical sign ->proteinuria
How can you definitively diagnose glomerulopathy?
Biopsy
What breeds are affected by glomerulopathy?
–Bernese Mountain Dogs, Cocker Spaniels, Samoyeds, Dobermanns and Rottweilers
What is the difference between the genetics of samoyeds and cocker spaniels with glomerulopathy?
- Samoyeds – genetic disorder inherited as X-linked dominant gene
- English Cocker Spaniels – autosomal recessive trait
What is this and what can happen?
- Disseminated changes in the kidney
- Biopsy: Generalised wide spread changes, dilated tubules, protein in the tubules pathologist can tell you it is an immature glomerulus!
What functional abnormalities are there? (3)
–Fanconi’s syndrome (impaired tubular resorption)
•Things like iron channels aren’t effective
–Primary renal glucosuria (resorption defect)
–Cysteinuria, hyperuricosuria and xanthinuria (all predispose to urolithiasis)
•Related to metabolism of protein and minerals
How common are ectopic urters?
•Common congenital abnormality in dogs
–Second most common cause of incontinence in the bitch
•Less common in cats, seen occasionally in large animals
–Sub clinical- may or may not notice
–Large animals may not live long enough for it to be seen as a problem
•More common in females vs. males
–Due to uteric buds coming out of the embryonic bladder (normal ureter at trigone)
What is an exctopic ureter?
- Normal ureters terminate at trigone
- Ectopic ureters bypass trigone and terminate distal to this, usually in urethra
–Females: urethra, vagina, cervix
–Males: urethra, vas deferens, seminal vesicles
Define intramural ectopic ureters and where is it most common?
–nter bladder wall normally but tunnel distally along wall to urethra or vagina
•Discharge is distal to sphincter, not discharging urine into bladeder!
–Most common presentation in dog
Define extramural ectopic ureters
Where is it most common?
–Bypass bladder to enter more distally (doesn’t even enter bladder, around the bladder and enters the urethra or other structure at a distal point)
–Most common presentation in cat
Where are ectopic ureters usually unilateral?
Females
What can be seen here?
Cut open bladder
Yellow – normal bladder boundary
Then wires have been used to catheterise.
Can see the opening is not in the normal boundary
Discharge urine beyond boundary = urinary incontinence and not contained in the bladder
What is the presenation of ectopic ureters in:
Large animals?
Dogs?
Cats?
- Large animals: rare congenital defect, reported horses, cattle and sheep
- Dogs: mainly mixed breed, some breed disposition identified
- Cats: no breed / familial predisposition
What are the clinical signs of ectopic ureters?
•Clinical signs are urinary incontinence
–Ureter not discharging where it should for the animal to voluntary expel
If you find an ectopic ureter how can we diagnose?
•Check for other developmental or acquired abnormalities of urogenital system (as lots of other things can go wrong and be associated)
How can we diagnose ectopic ureters? (4)
•contrast radiography, urethroscopy, vaginoscopy and cystoscopy in large animals
What is this image showing?
Ectopic ureter
Depending on ureter termination can get secondary changes so should evaluate other structures
Bottom kidney – terminating in abnormal position and urine able to leak out (kidney perfectly functional)
If there Is an obstruction = back up! Hydro ureter. Pressure build and back into kidney which will enlarge.