Nephrology/urology 3

Question 1

What factors can reduce host defences against UTI

Answer 1

Immunosuppression
Urine retention e.g in obstruction
Incomplete voiding with incontinence
Congenital abnormalities e.g vestibulovaginal remnant causing urine pooling, juvenile vagina, ecotpic ureter, sphincter incompetence
Damage to epitherlium e.g by catheterisation, masses
Dilute urine e.g in DM, HAC, CKD

Question 2

What pH suggests UTI

Answer 2

> 7.5 - with urease producing bacteria
But note than pH can be heavily influenced by diet

Question 3

When must we analyse urine sample within depending on storage method

Answer 3

Fresh - 1hr
Fridge - 24hrs
Boric acid preservative - 72hrs

Question 4

How many RBCs/WBS is it normal to see in sediment urine per high powered field

Answer 4

<5 WBCs
<3 WBCs if cysto, <8 if voided

Question 5

How many bacterial colonies is significant for cysto sample vs voided

Answer 5

> 1000colonies/ml with cysto sample
100,000/ml if voided

Question 6

WHat would be classed as uncomplicated bacterial cystitis

Answer 6

Normal urinary tract
<3 UTIs in a year
Females/neutered males

Question 7

Why should we always culture cat urine before treating for UTI but may not with dogs

Answer 7

Because cats often get idiopathic cystitis which is sterile

Question 8

Emperical antibioitc treatment in uncombilated bacterial cystitis

Answer 8

TMPS, amoxicillin, cephalexin
Give for 3-5 days; just want clinical cure

Question 9

What counts as a complicated UTI

Answer 9

Anything involving prostate or kidney, an underlying co-morbidity, abnormal structure or function of urinary tract
>3 infectinos in a year or >2 in 6 months

Question 10

What does relapse, persistent infection, re-infection and superinfection mean

Answer 10

Relapse = infection with same organism after proving bacterial cute (-ve culture); due to reservoirs in kidney

Persisten-t infection = can’t cure

Re-infection = infection with a different organism; due to same underlying factors e.g abnormal anatomy

Superinfection = infection with a different organism while still treating the first one
- Generally in those with catheters or with tumours

Question 11

When would we start with antibiotics without culture in uromar tract disesae

Answer 11

Uncomplicated UTIs in dogs; first time etc

Pyelonephritis suspicion because this is more serious

Question 12

What does increased urine echogenicity on ultrasound suggest

Answer 12

UTI

Question 13

What is pulse therapy and when might we use it in contect of UTIs

Answer 13

= giving 1/3 to 1/2 the dose every night for 6 months
For recurrent cases

Question 14

What organisms tend to cause UTIs

Answer 14

Most common is E coli
Also staphs, proteus (these two produce urease)
Strep etc

Question 15

How might a prostatitis case present

Answer 15

Entire male animal with UTI signs
- often chronic with vague signs; painful prostate, lethargic, pyrexic, constipated, lower UT signs

Could present like septic shock if abscess has ruptured

Question 16

Treatment for prostatitis and which antibiotics

Answer 16

Castrate to prevent recurrence
Antibioitcs for 4-6 weeks depending if acute or chronic
- Need to cross blood-prostate barrier so avoid amoxiclav - instead enroloxacin, TMPS, clindamycin

Question 17

What two stone types are most common and which is more common in young vs old dogs

Answer 17

Struvite (more common in young dogs due to association with UTIs)
Calcium oxalate (more so older)

Question 18

Risk factors for stone formation

Answer 18

Low fluid intake; more likely to saturate in concentrated urine

GEnetics
Stress can increase urine pH and make stones more likely
Diet

Question 19

GEnder balance with stone types

Answer 19

Females more prediposed to struvite
Males to calcium oxalate
Cysteine stones almost only seen in males (related to testosterone)

Question 20

What pH urine do different stones tend to form in

Answer 20

Struvite tends to form in alkaline urine
Others mostly in acidic

Question 21

Which stones are radiodense and which are radiolucent

Answer 21

Struvite and calcium oxalate are radiodense

URate are radiolucent

Question 22

What do struvite stones look like on X ray

Answer 22

Radiodense
Round

Question 23

What do calcium oxalate stones look like on X ray

Answer 23

Radiodense
Irregular shape c/f round struvites

Question 24

Which is the only crystal type that is always significant if found in urine

Answer 24

Cysteine

(also calcium oxalate monohydroxylate only seen in pathology)

Question 25

Which stones can be dissolved

Answer 25

- Struvite, cysteine, urate

Question 26

Which stones cannot be dissolved

Answer 26

Calcium oxalate

Question 27

When might we go to surgery rather than medically trying to dissolve stone

Answer 27

If it is calcium oxalate If there is an obstruction of ureter/urethra If there is just one single very large stone

Question 28

What can we use voiding urohydropropulsion

Answer 28

Smooth, small uroliths <4mm Not in very small animals or where there is urethral obstruction = filling bladder with saline, lifting dog up and squeezing bladder to push stones out

Question 29

Should we treat asymptomatic uroliths

Answer 29

Depends - If size that risks causing obstruction then yes If larger can wait until symptomatic If small can remove via voiding hydropropulsion or monitor

Question 30

What are the options for treating a urethrolith

Answer 30

Retrograde hydropropulsion + cystotomy LAser Urethrotomy = making hole in urethra; salvage procedure Urethrostomy = for recurrent obstructions to make a hole in urethra and divert urine out somewhere else to miss out blockage point

Question 31

What type of stones are do we suspect if found in kidney and ureter

Answer 31

Calcium oxalate

Question 32

When would we treat a ureterolith/nephrolith

Answer 32

If evidence of AKI If obstruction is causing worsening hydroureter/hydronephrosis, pain, recurrent infections

Question 33

How would we medically manage kidney/ureter stones

Answer 33

Smooth muscle relaxants Analgesia Fluids Diuretics Not that successful Should go to surgery within 2 days for cats; can wait longer in dogs if non-obstructive

Question 34

Surgical options when dealing with nephroliths/ureteroliths

Answer 34

Ureteral stent to keep open Subcut ureteral bypass implant nephrotomy ureterotomy but high complication rate Remove ureter + kidney totally

Question 35

How to prevent stone recurrence

Answer 35

Want dilute urine - Wet food, water intake, high Na+ diet to increase water volume

Question 36

What are struvite crystals made of

Answer 36

Magnesium ammonium phosphate

Question 37

Which animals do struvite calculi tend to form in and what is different between them

Answer 37

FEmale dogs; assocaited with UTI and urease producing gram -ves that increase pH Cats; often sterile

Question 38

Treating struvite calculi and how is it different in cats and dogs

Answer 38

Medical dissolution - Acidify urine, dilute urine, moderate phosphate and magnesium restriction In dogs want antibiotic course during this Cats no antibiotics but must keep this diet for life STones gone in ~1month

Question 39

ARe struvite crystals in a dog with no UTI relevant

Answer 39

No

Question 40

What are the two types of ways that calcium oxalate calculi form

Answer 40

Normocalcaemic animals; related to reduced renal tubular reabsorption nad increased GI tract absorption = most common HYpercalcaemic hypercalciuria; secondary to the hypercalcaemia and won't get once this is treated

Question 41

How to prevent more calcium oxalate stones forming

Answer 41

Dilute urine Slightly alkalinise urine - make a neutral pH Can use thiazide diuretic

Question 42

Signalment for cystine calculi

Answer 42

Young male entire dogs

Question 43

What are types 1, 2 and 3 cystine calculi

Answer 43

1 and 2: genetic due to AA transporter mutation; mutation stops cystine reabsorpton from renal filtrate so more in urine e.g Newfoundland, labrador 3: androgen dependent; high recurrence rate e.g in deerhound, irish terrier, bulldogs, rotties

Question 44

What are the two causes of urate calculi

Answer 44

1) Genetic mutation that causes excretion or uric acid rather than soluble product allantoin e.g in dalmations, english buldogs 2) With porto-systemic shunts/severe hepatic disease that causes less conversion of ammonia to urea and uric acid to allantoin

Question 45

What can we use to alkalinise urine and when might we do this

Answer 45

Potassium citrate With urate, cystine or calcium oxalate stones (i.e anything but struvite)

Question 46

Treating cytine calculi in dogs

Answer 46

INcrease fluid intake Neuter males; helps those which are androgen dependent (i.e type 3) Restrict protein intake Alkalinise urine with potassium citrate 2-MPG can be used to reduce cystine to more soluble cysteine

Question 47

Treating/preventing urate calcli

Answer 47

Low protein diet Alkalinise urine if acidic with potassium citrate Can use allopurinol to stop uric acid formation via xanthine oxidase inhibition Ligate porto-systemic shunt of present

Question 48

What are the most common causes of urinary tract disease in cats

Answer 48

FEline idiopathic cystitis Urolithiasis UTI - MORE OFTEN non-obstrucive

Question 49

Risk factors for feline idiopathic cystitis

Answer 49

Middle age, dry food, litter tray use, indoor cat, multi-cat house, obese, nervous 60% recurrene rate

Question 50

How do diagnose feline idiopathic cystitis

Answer 50

by excluding other causes - rule of urolithiasis, UTI, neoplasia This is STERILE inflammation

Question 51

Treating feline idiopathic cystitis

Answer 51

Analgesia; sublingual buprenorphine Anti-spasmodics; prazosin and dentrolene to work on both smooth and striated muscle of feline urethra Long term aim = REDUCE STRESS; less competition between cats for litter trays etc, wet food, more water intake etc