Intro to disorders Flashcards
What are some things that owners may report of seeing?
Discoloured urine Pollakiuria - increased frequency Stranguria - straining, painful Dysuria - difficult or painful Nocturia - urinating at night Polyuria/polydipsia Urinary incontinence Vomiting Anorexia Depression Weight loss etc.
Define azotaemia and uraemia?
Azotaemia
-Increased concentration of non-protein nitrogenous substances, mainly creatinine and urea
Uraemia
-Consequences of azotaemia, the clinical signs
What are some common problems associated with urinary tract disorders?
Azotaemia Uraemia Proteinuria Urethral obstructoin Urinary calculi Urinary tract infection Idiopathic lower urinary tract inflammation
How can you differentiate haemoglobinuria from myoglobinuria?
By taking a sample and spinning it down
If from myoglobin, the serum will be clear and will have no anaemia
If from haemoglobin, the serum will have haemolysis and anaemia
What is haematuria?
Blood in the urine
If you see red/brown urine, what are the 2 broad categories of what it could be?
Haematuria
Pseudohaematuria/Pigmenturia-Haemoglobinuria or myoglobinuria
What is haemoglobinuria usually indicate?
Intravascular haemolysis
If you find haemoglobinuria, what 3 things should you then check/look for?
Check for anaemia and autoagglutination
Directly check for intravascular haemolysis
Look for underlying causes of haemolysis
What are the 6 main differentials for haemoglobinuria?
Immune mediated haemolytic anaemia with intravascular haemolysis Toxicity - Zinc, onion, copper Vena caval syndrome DIC Microangiopathy Inherited RBC defects
How can vena caval syndrome look like haemoglobinuria?
Because of the clots associated with it, this causes bursting of RBC’s as they go past
How can microangiopathy look like haemoglobinuria?
The fibres in the vessels cause garroting of RBC’s
What organ is responsible for immune-mediated haemolytic anaemia?
The spleen
What does myoglobinuria indicate?
Severe muscle damage
- Tying up
- Snake envenomation
What does haematuria indicate?
Bleeding into the urogenital tract
What do you need to check if you find haematuria?
Check the urogenital structures for local bleeding lesions
-If none found then look at haemostatic disorders as root cause
What are the 3 differential diagnosis for haematuria?
Bleeding from genital structure -Prostate, vagina, uterus Bleeding from urinary tract -Urethra, bladder, kidney, ureter Haemostatic disorder
When will you see haematuria only at the beginning of the urine stream?
When it is from the urethra or other lower urinary structures
When will you see bleeding from the prepuce or vulva at times other than urination?
If it is from the prostate or female reproductive tract
When will you see haematuria associated with a lot of straining and increased frequency of urination?
When it is from a local source
When will you see haematuria with RBC casts present in the urine sediment?
When it is coming from the kidneys
4 year old male Doberman Pinscher
Occasionally has blood at the start of his urine stream. Sometime he also drips blood from his prepuce other than urination. Otherwise he feels well.
Where is the blood coming from?
Either the prostate or urethra
3 year old male Welsh Corgi.
Has blood mixed in thoroughly with urine. Urine sediment shows RBC casts, few WBC’s and no bacteria. No straining or increased frequency of urination.
Where is the blood coming from?
The kidneys
-Either renal tubules or glomeruli most likely
What are the 2 categories of causes of straining to urinate?
Obstruction
Inflammation
What are 4 things that can cause urethral obstruction leading to pollakiuria/stranguria/dysuria?
Calculi - Stones, uroliths
Mucus or struvite plugs
Neoplasia
Functional - reflex dyssynergia
What is the most common neoplasia of the bladder and urethra?
Transitional cell carcinoma
What are 4 things that can cause lower urinary tract inflammation leading to pollakiuria/stranguria/dysuria?
Bacterial infections
Sterile urethrocystitis
Cystic calculi - Urolithiasis
Bladder/urethral neoplasia
What 4 things should you exam in a patient with pollakiuria / stranguria / dysuria?
Palpate bladder and do rectal exam before and after urine is voided - feel for calculi, masses, thickening
Obtain urine by cystocentesis for UA, culture and sensitivity
Consider imaging studies
If unsure about urethral patency, pass a urethral catheter
How much water intake do you consider polydipsia?
Definition is 100ml/kg/day
If cold 40 ml/kg/day
If hot climate 60 ml/kg/day
-There is a big variance
Instead of just relying on water intake, what can be another indicator of polydipsia?
Urine specific gravity
For USG what are the measurements for hyposthenuria, isosthenuria and hypersthenuria?
Hyposthenuria SG under 1.008
Isosthenuria SG 1.008 - 1.012
Hypersthenuria SG over 1.012
What do you need to remember when determining if a USG is hypersthenuric?
That there are 2 classes
- Minimally concentrated SG 1.013 - 1.030/6
- Well concentrated SG over 1.030/5
What do you need to remember about cats and hypersthenuria?
That even when going into renal failure, they will still produce minimally concentrated urine
-USG 1.013 - 1.035
What does hyposthenuria tell you?
That the kidneys are actively diluting urine
What does isosthenuria tell you?
That there is some pathological process going on, and the kidneys either can’t keep up or aren’t working
What does hypersthenuria tell you?
That the kidneys are actively concentrating
Or that there are large amounts/sized solutes
-They are still doing some work
Dogs that are in chronic renal failure will typically produce urine that is what?
Isosthenuric
1.008 - 1.012
Cats that are in chronic renal failure will typically produce urine that is what?
Minimally concentrated
- Not as concentrated as it would be if azotaemia was only prerenal
1. 013 - 1.035
What are 5 differential diagnosis for primary polydipsia?
Psychogenic Hepatic insufficiency or disease Hypothalamic disorder Some drugs -Chlorpromazine, anticholinergics Hyperthyroidism
What 2 ways can hyperthyroidism cause primary polydipsia?
Can feel hotter than they really are
Or treating a dog with too high of a dose for hypothyroidism
What 2 things do you need for concentrated urine?
Renal tubule cells
-Set up countercurrent multiplication
Antidiuretic hormone
-Interacts with receptors on tubule cells
-Cause anti-diuresis
What are the 2 differential causes for primary polyuria?
Neurohypophyseal diabetes insipidus
-Can’t produce ADH
Nephrogenic diabetes insipidus
- Congenital or acquired
- Can’t respond to ADH
What is the most common cause for primary polyuria?
Acquired (secondary) nephrogenic diabetes insipidus
List some differentials for primary polyuria? (What else could be causing similar signs)
Renal insufficiency/failure Pyelonephritis Pyometra Hypercalcaemia Hypokalaemia Hyper & hypo adrenocorticism Hyperthyroidism Hepatic insufficiency/failure Diabetes mellitus Post obstruction diuresis Primary renal glucosuria (Fanconi syndrome) Drugs and toxins -Mannitol, dextrose, diuretics, nephrotoxic drugs
How can both hypo and hyper adrenocorticism cause polyuria?
Hyperadrenocorticism - Disrupts ADH transduction
Hypoadrenocorticism -
Decreased sodium cause disruption of countercurrent multiplier
How can diabetes mellitus cause polyuria?
Glucose is osmotically active and water will follow it out
Why should you do a rectal exam when examining a patient for PU/PD?
Apocrine gland adenocarcinoma of the anal gland
Why should you do chest radiographs as part of further testing in a patient with PU/PD?
Lymphoma of cranial mediastinum can cause hypercalcaemia
