Final Flashcards
What are the functions of a normal kidney?
Fluid and electrolyte balance
Excretion of nitrogenous wastes
Erythropoietin
Renin
Vitamin D activation
Filtration (glomerulus)
Reabsorption and secretion (tubular)
What is azotemia? What is uremia?
Azotemia: accumulation of nitrogenous wastes BUN and/or creatinine)
Uremia: clinical signs associated with renal failure
What is the difference between pollakiuria and polyuria?
Polakiuria: increased frequency, small amounts
Polyuria: large amounts
What are systemic clinical signs of renal failure?
Fever
Body condition
Oral ulcers
Pale MM
Which tests evaluate the upper vs lower urinary tract?
UA: both upper and lower
Serum chemistry: upper
Renal function tests: upper
Imaging: upper and lower
What produces creatinine? How is it excreted? Is it secreted or reabsorbed?
Produced by muscle
Excreted by filtration
Neither secreted or absorbed
What produces BUN? How is it excreted? Is it secreted or reabsorbed?
Produced by liver
Excreted by filtration
Also secreted and reabsorbed
When should you evaluate a urine sample?
Within 1 hour of collection
Reagent urinalysis strips are reliable for assessing which parameters?
WBCs,
Nitrites
Urobilinogen
SG
What factors affect the accuracy of reagent urinalysis strips?
Moisture
Alkaline urine
Discolored urine
What ketone does chemical urinalysis accurately test for?
Actoacetate
How do you tell the difference from blood, hemoglobin, and myoglobin in urine?
Spin down urine -> pellet on bottom with clear supernate = blood, no pellet = myoglobin or hemoglobin
To differentiate between myoglobin and hemoglobin, need to spin down blood -> pellet with clear supernate = myoglobin, red supernate = hemoglobin
What are differentials for bilirubin in urine?
Hemolysis
Liver disease
Bile duct obstruction
What is important to keep in mind when evaluating casts?
They will dissolve is urine is allowed to sit before analysis
What type of cast is indicative of on-going renal disease?
Cellular
Does absence of casts rule out renal damage?
NO
Fat is common in the sediment of what species?
Cats
T/F: crystalluria is not always pathogenic?
True
Can you tell which urine is more concentrated by comparing color?
No
What are the defining parameters for AKI?
Increase in creatinine by > 0.3 mg/dL in 48 hours
Increase in creatinine > 1.5 x baseline
Urine production < 0.5 mL/kg/hr (6 hours)
What is the principle biomarker of AKI?
Creatinine
What defines normal urine output, oliguria, and anuria?
Normal: 20-50 ml/kg/day or 1-2 ml/kg/hr
Oliguria: < 1 ml/kg/hr
Anuria < 0.1 ml/kg/hr
What is the RIFLE staging system of AKI?
Risk: inc. Cr 50-100% or UO < 0.5 ml/kg/hr > 6 hrs
Injury: inc. Cr 100-200% or UO < 0l.5 ml/kg/hr >12 hrs
Failure: inc. Cr >200% or > 4mg/dL or UO < 0.3 ml/kg/hr for > 24 hrs or anuria >12 hrs
Loss of function: need dialysis for > 4 wks
End-stage renal disease: need dialysis for > 3 mo
What is the IRIS staging system of AKI?
Used in vet med
Grades 1-5 based on rises in serum Cr
What are the main clinical signs that differentiate AKI from CKD?
AKI: acut onset of clinical signs, normal BCS
CDK: chronic, decreased body condition
What are causes of renal tubular injury?
Toxins (ethylene glycol, lillies, grapes/raisins)
Nephrotoxic drugs (abx, NSAIDs, radiocontrast agents)
Metabolic dz (hypercalcemia)
Endogenous substances (myoglobin, hemoglobin)
What causes interstitial nephritis?
Pyelonephritis
Leptospirosis
Granulomatous disease
Neoplasia
What causes glomerular disease?
Immune-mediated complex deposition causing inflammation of the glomerulus (glomerulonepehritis)
What is the most common cause of AKI in cats?
Urinary obstruction
What is the most common cause of AKI in dogs?
Unknown
Elevated anion gap, ionized hypocalcemia, and calcium oxalate monohydrate crystals may be observed following what cause of AKI?
Ethylene glycol toxicity
What changes in hematocrit are seen with AKI?
Normal or elevated
A positive urine culture raises concern for what cause of AKI?
Pyelonephritis
What types of fluid should be avoided in the treatment of AKI?
Chloride-rich solutions
Synthetic colloids
What is the definition of fluid overload?
More than 10% increase in BW from baseline
What are the main goals of nutritional support in treatment of AKI?
- Preserve lean body mass
- Avoid further metabolic complications
- Support immune system
- Improve GI tract function
Give a phosphate binder with each meal!
What should you avoid force feeding renal diets?
Creates aversion
What are the indications for dialysis?
Severe hyperkalemia
Severe fluid overload
Severe acid-base disturbance
Sever or progressive azotemia
Oliguria/anuria
Pre-surgical conditioning
What is the cause and treatment or uremic gastritis?
Cause: decreased Gastrin elimination
Tx with antiemetics and reduce acid production
Antiemetics: cerenia, ondansetron, metoclopramide
Decreased acid production: H2-blockers, proton pump inhibitors, sucralfate
What is true about using furosemide?
No evidence supports the use of loop diuretics, used as a rescue protocol
What is fenoldopam?
Dopamine-1 receptor antagonist used to increase GFR but ultimately there is no change in renal funtion
What vasopressor is recommended for use in AKI to restore blood pressure and urine output?
Norepinephrine
What are the types of renal replacement therapies?
Therapeutic Plasma Exchange (TPE)
Hemoperfusion
Intracorporeal: Peritoneal dialysis
Extracorporeal: Intermittent Hemodialysis (IHD), Continuous Renal Replacement Therapy (CRRT)
What is the difference between Intermittent Hemodialysis and Continuous Renal Replacement Therapy?
IHD: 3-6 hours, most efficient, “saw tooth” excursions with greater risk of complications, water purification systems, non-portable
CRRT: Long >24hr sessions, less efficient, replacement fluid before or post filter, Sterile dialysate, portable, more expensive
What is the prognosis of AKI with hemodialysis?
~50%
What do beta receptors control?
Bladder relaxation
What do alpha receptors control?
Bladder contraction, increase tone of internal urethral sphincter
Which nerves control bladder filling?
Hypogastric n. and pudendal n.
Which nerves control the voiding phase?
Distention -> pelvic n.
Pain/over-distention -> hypogastric n.
What does acetylcholine control?
Contraction of bladder
What are the characteristics of storage disorders?
Voluntary urination is normal
Involuntary leakage
Normal residual volume
stranguira is uncommon
What are the characteristics of voiding disorders?
Voluntary urination is abnormal -> stranguria, pollakiuria, diminished urine stream, usually postures
Increased residual volume
What are examples of storage disorders?
Urethral incompetence
Detrusor relaxation
Ectopic ureter
What is the most common storage disorder?
Urethral sphincter mechanism incompetence (USMI)
Spayed female dogs, incontinence at rest
What is the cause of urethral sphincter mechanism incompetence and what is the treatment?
Cause: decreased estrogen-> inc collagen and dec muscle
Tx: phenylpropanolamine (alpha adrenergic agonist), estrogen
What disorders are considered urethral incompetence?
Urethral sphincter mechanism incompetence
Pelvic bladder
How do you diagnose pelvic bladder and what is the treatment?
Dx: clinical signs and rads
Treatment: similar to USMI (PPA) +/- surgery
What is a bladder relaxation disorders?
Detrusor spasticity
What are the clinical signs of detrusor spasticity, what are possibly causes, how do you diagnose it, and what is the treatment?
CS: sudden voiding with small bladder
Cause: usually secondary to inflammation (infection, cystoliths, neoplasia, idiopathic)
Dx: presumptive, cystometrography
Tx: Treat underlying disease!/enhance bladder relaxation with anticholinergics
What are the clinical signs of ectopic ureters, how do you diagnose it, and what is the treatment?
Cs: constant dribbling of urine
Dx: cystoscopy, contrast radiography or CT,
Tx: Laser ablation (intramural), surgery, manage like USMI
What are examples of voiding disorders?
Detrusor contraction (atony or LMN disease)
Urethral relaxation
physical obstruction
What are the clinical signs of detrusor atony?
Large, soft bladder,
Stranguira with minimal/weak stream
Large residual volume
May see “overflow” incontinence
What are the clinical signs of LMN disease?
Distended, flaccid bladder
Decreased anal tone and perineal reflex
+/- paraparesis/paralysis
What is the treatment for detrusor atony?
Neurogenic: fix underlying problem
Non-neurogenic: relieve physical obstruction or address functional obstruction
Re-establish tight junctions, keep bladder small, stimulate detrusor contraction -> bethanecol
Do not do this if urethral obstruction present!
Which class of drug would you use to relax the internal urethral sphincter?
Alpha- adrenergic antagonist
What are the clinical signs of urethrospasm?
Relatively common post-catheterization, especially cats
Stranguria, pollakiuria,
Large, firm bladder
Initial normal stream then stops
What is the treatment for urethrospasm?
Internal sphincter: a-antagonist (phenoxybenamine, prazosin, tamsulosin– dogs only)
External sphncter: diazepam, alprazolam, midazolam, ace
What do upper motor neuron lesions result in?
Loss of voluntary bladder function
Tetra or para-paresis
Hyperreflexia
CP deficits
What is a main clinical sign of physical obstruction?
LOW heart rate
What do you do if you suspect urethral obstruction?
- Check electrolytes/address hyperkalemia
- Rads
- Relieve obstruction
What do pelvic or pudendal n. Lesions result in?
Pelvic -> detrusor atony
Pudendal -> external sphincter dysfunction
Drug of choice for detrusor atony?
Bethanecol
Drug of choice for urethrospasm?
Phenoxybenamine
What is the difference between macroscopic and microscopic hematuria?
Macroscopic: can see grossly
Microscopic: no visible discoloration but > 5 RBCs per hpf
What are differentials for hematuria without dysuria?
UPPER URINARY TRACT
Renal neoplasia * most common*
Trauma
Heat stroke
Coagulopathy
These animals are usually very sick
What are differentials for hematuria with dysuria?
LOWER URINARY TRACT
Cystitis
Urolithiasis
prostatitis
Benign prostatic hyperplasia
Neoplasia
Trauma
What are differentials for hemoglobinuria?
IMHA
DIC
Heat stroke
Caval syndrome
What are nephrotoxic drugs used in LA medicine?
Phenylbutazone
Aminoglycosides
What is normal water consumption and urine output for horses?
Intake: 40-60ml/kg/day
Output: 5-20 ml/kg/day
What structures can be felt on transrectal palpation in horses?
Caudal pole of L kidney
Bladder
Prox urethra
What structures can be felt on transrectal palpation in cattle?
L kidney
Ureters
BLadder
urethra
What structures can be felt on transrectal palpation in small ruminants?
Proximal urethra
Bladder
What structure can a urinary catheter get stuck on when catheterizing female cattle?
Suburethral diverticulum
How can you stimulate urination in small ruminants?
Cover nose and mouth
In LA, what is indicative of glomerulonephritis?
Hypoalbuminemia
Why is BUN not routinely measured in cattle?
Almost all BUN goes through GI and very little is excreted by kidneys
In LA, which serum abnormalities are seen with AKI?
Decreased Na, Cl, Ca
Inc K, Mg, P
What serum electrolyte abnormalities are seen in CKD in horses?
Increased Ca
Decreased P
What is the normal urine appearance for ruminants? Horses?
Ruminants - clear, straw color
Horses- cloudy, straw colored
Herbivores will have alkaline urine except:
High protein diet
Anorexia
Neonates
What will falsely increase USG in LA?
Protein or glucose
USG < 1.008 is normal in which animals?
Suckling foals
Isosthenuria is normal in what type of animals?
High producing dairy cows
Fractional clearance of what molecule can help differentiate between pre-renal and renal azotemia?
Na
Normally <1%
What factors can alter fractional clearances?
IV fluids
Furosemide
Exercise
What is an early indicator of proximal tubule damage that will increase quickly with aminoglycoside toxicity?
GGT
What GGT/creatinine ratio is clinically relevant?
> 100 U/g
Where in the nephron is glucose reabsorbed? What is the threshold?
Proximal tubule
150 mg/dL
What are the complications associated with renal biopsy?
Hemorrhage
Bowel penetration
“End stage kidney disease”
What does nuclear scintigraphy assess?
Renal perfusion
What is the most common cause of AKI in large animals?
Acute tubular necrosis
Which is the most nephrotoxic aminoglycoside?
Neomycin > kanamycin > gentamicin > amikacin > streptomycin
What are the nephrotoxic antimicrobials?
Aminoglycosides
Oxytetracycline
Polymixin B
Amphotericin B
What antimicrobials are effective in the treatment of Leptospirosis?
Doxycycline, amplicllin, penicillin, amoxicillin, ceftiofur
What renal disease is caused by immune complex deposition by Strep (LA)?
Acute glomerulonephritis
What are the clinical signs of post-renal (obstructive) azotemia in foals?
Dysuria, colic
Lordotic back, tail flagged, frequent attempts to urinate
What signs on ultrasound are indicative of AKI (LA)?
Perirenal edema
Hypoechogenicity
Loss of corticomedullary distinction
Dilation of renal pelvis
What is the medical treatment of hyperkalemia in AKI in LA?
0.9% NaCl fluids
5% dextrose
Calcium gluconate
Sodium bicarbonate
Insulin
What are the clinical signs of CKD in LA?
Chronic weight loss most common
Rough hair coat
Poor athletic performance
PU/PD
Ventral edema
Uremic halitosis
Urea excretion in sweat
Dental tartar, gingivitis, oral ulcers
Is the degree of PU/PD related to the severity of azotemia?
No
What electrolyte abnormalities are associated with CKD in LA?
HyperCa
Hypo P
What is the prognosis for CKD?
Cr < 5 mg/dL = may manage for months-years
Cr > 10-12 = marked compromise
Cr > 15 mg/dl = grave
What are the clinical signs of uroperitoneum in foals?
Abdominal distention
Colic
Stranguria, pollakiuria
Lethargy, depression, anorexia
What are the lab findings that are consistent with uroperitoneum?
Post-renal azotemia
Hypo Na, hypoCl, hyperK
Abdominocentesis: peritoneal Cr > 2x serum Cr
What is the medial treatment for uroperitoneum?
0.9% NaCl, 5% dextrose, Ca gluconate, Na bicarbonate
Antimicrobials
Abdominal drainage
What is the most common urolith in large animals?
Calcium carbonate
What are the clinical signs of cystoliths in large animals?
Hmaturia post exercise
Stranguira
Incontinence
recurrent colic
What is the treatment for urolithiasis in mares?
Manual removal: crushing, lithotripsy, urethral sphincterotomy
What is the treatment of urolithiasis in male horses?
Pararectal cystotomy
Perineal urethrosctomy
Cystotomy
Flank (nephrectomy, ureterotomy)
What is the incidence of recurrence of urolithiasis in large animals?
41% recurrence within 1-32 months
Pathology of which organ does hematuria throughout the stream indicate? Beginning of stream? End of urination?
Throughout: kidneys, bladder
Beginning of stream: distal urethra
End of urination: proximal urethra
What is idiopathic renal hematuria?
Sudden onset, life-threatening hematuria
Blood clots from one or both kidneys
No age or sex predisposition, but >50% arabians
What other diseases must you rule out to diagnose idiopathic renal hematuria?
Renal adenocarcinoma
Coagulopathy
How do you treat idiopathic renal hematuria?
Supportive care
Blood transfusions
Medications to promote hemostasis
Unilateral nephrectomy
Dexamethasone
What can cause hematuria from the bladder in large animals?
Cystolith
Neoplasia
Blister beetle toxicity
How do you diagnose cantharidin toxicity?
Hypocalcemia
Hypomagnesemia
Azotemia
ID beetle in hay, GI contents, or urine
Hematuria caused by the urethral or external genitalia may be caused by
Neoplasia (squamous cell carcinoma)
habronemiasis
Urethral tear
Where in the urethral are. Tears common? What is the most common clinical sign?
At the level of ischial arch, dorsocaudal aspect
CS: bright red urine att the end of urination
No pollakiuria, dysuria
QH geldings
How do you treat urethral tears?
Benign neglect
Subischial perineal urethotomy
Corpus spongiosum incision
Buccal mucosal graft
How is bacterial cystitis treated in horses?
TMS, penicillin, cefitiofur*
Diuresis
Acidify urine
What are the clinical signs of pyelonephritis in horses?
Signs of systemic inflammatory disease
What is the difference between upper and lower motor neuron causes of incontinence in horses?
UMN: increased urethral resistance , pollakiuria, sporadic dribbling
LMN: relaxed bladder and sphincter, continuous dribbling, cauda equina syndrome, loss of anal/tail tone, hindlimb weakness, perineal analgesia
What is myogenic bladder incontinence?
Idiopathic or secondary to obstruction
Weight of sediment stretches detrusor and breaks down tight junctions
Causes inability to depolarize and cannot maintain sphincter
What is the treatment of sabulous cystitis in horses?
Treat any bacterial infection
Lavage bladder
Stimulate bladder emptying (bethanecol)
What defines polydipsia and polyuria in horses?
Urine output >50 ml/kg/day
Water consumption >100 ml/kg/day
How do you differentiate between a psychogenic drinker, neurogenic diabetes insipidus, and nephrogenic diabetes insipidus?
Psychogenic drinker will respond to water deprivation test
Neurogenic DI: only responds to vasopresin
Nephrogenig DI: Does not respond to anything
How does PPID cause PU/PD?
Cortisol antagonism of vasopressin
What causes acute tubular necrosis in ruminants?
Vasomotor nephropathy
Antimicrobials
NSAIDs
Metals
Vit D
Cholecalciferol rodenticides
Ethylene glycol
What causes hemoglobinuria in ruminants?
Post-parturient hemoglobinuria
Copper toxicity
Bacillary hemoglobinura
Water intoxxication
Salt poisoning
Selenium deficiency
What causes myoglobinuria in ruminants?
White muscle disease (Vit E, Se deficiency
Senna occidentalis plant
How does oak toxicity cause AKI in ruminants? What are the CS? What is the Tx?
Tannins hydrolyzed in rumen and are toxic to renal tubules
Causes cotipation, melena, weight loss
Causes azotemia, proteinuria, glucosuria
Tx: support, prevention
How does pigweed cause AKI in ruminants? What are the CS and lab findings?
Oxalates chelate calcium
Causes weakness, tremors, ataxia, and recumbency
Causes azotemia, proteinuria, and hyperkalemia
What causes amyloidosis and what are possible sequelae?
Caused by inflammatory disease
Causes PLN -> loss of albumin and antithrombin 3 -> thrombosis (pulmonary or renal)
Diarrhea
What causes acute and chronic glomerulonephritis in ruminants?
Acute: pregnancy toxemia
Chronic: immune-mediated: BVD, hog cholera, african swine fever
Inherited: Finidh Landrace lambs
What causes pyelonephritis in ruminants?
Corynebacterium renale
E. Coli
C. Psuedotuberculosis, T. Pyogenes, Salmonella, Staph aureus
What are the clinical signs of pyelonephritis in ruminants?
Colic, arched back, treading, tail swishing
fever, depression, inappetence, decreased milk production
Blood, pus, crystals on vulva
What is the treatment for pyelonephritis?
G+: penicillin
G -: cefitofur
What are the most common sites of obstruction in small ruminants? Cattle?
Small ruminants: urethral process
Cattle: sigmoid flexure
Walpoles solution can be used to dissolve what kind of stones?
Struvite stones
Which surgical treatment of urolithiasis is best for breeding future?
Tube cystotomy
How can you prevent urolithiasis in ruminants?
Increase forage
Acidify urine
Encourage water consumption
Delay castration
Avoid estrogenic growth stimulants
What is “pizzle rot” and what causes it?
Ulcerative posthitis and vulvitis
Corynebacterium renale
Chronic ingestion of what plant may cause hematuria, bladder neoplasms, dysuria, pollakiuria, and death?
Bracken fern
Which stones for because of a increase in solute? Which stones form because of a lack of inhibitors?
Increase in solute: struvite, urate, cystine
Lack of inhibitors: calcium oxalate
What is the order of least invasive to most invasive techniques for removing stones?
- Dissolution
- Catheter
- Voiding
4 Lithotripsy
5 Lap assisted Sx
- Sx
What type of stones are associated with UTIs?
Struvite
What are predisposing factors for CaOx stones?
Breed (mmin schnauzer, shih tzu, lahaa apso, yorkies)
Obestiy
Glucocorticoids
Primary hyperparathyroidism
Chronic metabolic acidosis
What factors contribute to bacterial virulence?
Capsular antigens
Hemolysins
Plasmids
Urease production
What are the host defenses against UTI?
Micturition
Anatomy
Mucosal barriers
Urine
What can cause asymptomatic bacteruria?
Cushing’s
Chemo patients
Chronic kidney disease
How long should you treat uncomplicated bacterial cystitis? Complicated bacterial cystitis?
Uncomplicated: 10-14 days
Complicated: 4-8 weeks
How can you treat frequent UTIs?
Treat with 1/3-1/2 antibiotic dose before bed
Methenamine hippurate- urinary antiseptic converted to formaldehyde in bladder
What are the goals for CKD management?
Good quality of life
Delay onset of uremic crisis
Slow progression
Improve survival time
What are the goals of controling serum phorphorus concentrations?
Minimize progression of CKD
Prevent tissue mineralization
Avoid 2ndary hyperparathyroidism
How can you control serum phosphorus levels in patients with CKD?
Phosphate binders
Aluminum based
Calcium based
How can you control hypertension in animals with CKD?
Na restriction
ACE inhibitors
Ca channel blocker
Hydralazine
How do you control proteinuria in patients with CKD?
ACE inhibitors
How do you control acid-base balance in patients with CKD?
K+cirtrate unless hyperkalemic
What tests are available for detecting urine protein?
Dipstick colormetric test
Sulfasalicyclic acid test
POC microalbuminemia test
quantitative assay
What is the standard therapy for proteinuric kidney disease?
RAAS inhibition (enalapril)
Diet
Aspirin
Anti-hypertensives
Will a cat with FLUTD have PU/PD?
Usually no