Elimination & Detox 2: Equine Nephrology Flashcards
the kidney’s job is to….
THEREFORE, in RENAL FAILURE, the kidney is unable to…
the kidney’s job is to…
–> REGULATE THE OSMOLARITY (how concentrated) OF THE BLOOD
THEREFORE, in RENAL FAILURE, the kidney is unable to ADJUST THE OSMOLARITY OF BLOOD & thus CANNOT CONCENTRATE or DILUTE BLOOD and thus URINE
osmolarity definition
the CONCENTRATION of a SOLUTION expressed as the TOTAL NUMBER OF SOLUTE PARTICLES per LITER
if you are in RENAL FAILURE, what is the LIKELY RANGE of USG VALUES you would have?
what is this condition called?
RENAL FAILURE –> ISOSTHENURIA!
1.008 –> 1.012
if you’re in RENAL FAILURE, what would your USG likely be at…
THE END OF A LONG HIKE ON A HOT DAY?
after DRINKING A BUNCH OF BEER?
LONG HIKE = 1.012 (as concentrated as you can get with isosthenuria)
AFTER BEER = 1.008 (as dilute as you can get with isosthenuria)
FRACTIONAL EXCRETION (Fex)…
if the TUBULES are DAMAGED, then _____ ____ DECREASES & ____ ____ gets HIGHER
NORMAL fractional excretion should be around ___% because…
DAMAGED TUBULES = ELECTROLYTE RESORPTION DECREASES, so FRACTIONAL EXCRETION IS HIGHER
NORMAL fractional excretion should be around 1% because KIDNEYS SHOULD RESORB MOST OF THE SODIUM & CREATININE
what 2 kinds of cells make GGT?
in both, WHAT stimulates this to be made?
2 kinds of cells?
1. HEPATIC BILIARY TUBULAR CELLS
2. RENAL TUBULAR CELLS
in both, made in TIMES OF STRESS
if a HORSE has…
HIGH URINE GGT = ????
HIGH BLOOD GGT = ????
HIGH URINE GGT = DEFINITELY RENAL DZ
HIGH BLOOD GGT = from LIVER, so NOT SURE WHAT’S GOING ON
3 common Ddxs for DEHYDRATION?
- DECREASED INTAKE (not drinking enough)
- INCREASED LOSS (GI/URINARY)
- THIRD SPACE picking up FLUID but PUTTING IT WHERE YOU CANNOT SEE IT
in PRE-RENAL AZOTEMIA, what should the SODIUM levels be?
SODIUM SHOULD BE NORMAL to HIGH because KIDNEY NORMALLY HELPS SAVE SODIUM
if ____ levels are NORMAL, then ______ AZOTEMIA is LESS LIKELY
POTASSIUM, POST-RENAL
PRE-RENAL AZOTEMIA (in horses)…
USG?
hydration status?
urine volume?
additional info? (3)
USG = >1.025
hydration status = DEHYDRATED
urine volume = DECREASED
additional info? = can also have DECREASED RENAL PERFUSION due to…
1. HEMORRHAGE
2. SHOCK
3. DECREASED CO
RENAL AZOTEMIA…
USG?
hydration? + 1 clinical sign
urine volume if ACUTE or CHRONIC renal failure? (2)
additional info? (2)
USG = 1.008 –> 1.012
hydration? = DEHYDRATED + POLYURIA (kidney can’t hold onto water)
urine volume?
1. CHRONIC RENAL FAILURE = INCREASED
2. ACUTE RENAL FAILURE = DECREASED
additional info?
1. look for ELECTROLYTE CHANGES
2. can have MILD ANEMIA if CHRONIC RENAL FAILURE
POST-RENAL AZOTEMIA…
USG?
hydration?
urine volume?
what chem finding should we find?
4 possible pathologies?
USG = VARIABLE
hydration? = NORMAL to DEHYDRATED
urine volume = DECREASED
chem finding = INCREASED POTASSIUM
4 possible pathologies?
1. STRANGURIA
2. DYSURIA
3. RUPTURED BLADDER
4. UROPERITONEUM
TRUE/FALSE
ISOSTHENURIA IS ALWAYS ABNORMAL.
defend it
FALSE, could just have DRANK A TON OF WATER
when is ISOSTHENURIA ABNORMAL?
when the patient is DEHYDRATED and wants to CONCENTRATE URINE & HOLD ONTO MORE WATER
if we see CASTS in URINE SEIDMENT, can suggest…
ACUTE RENAL FAILURE
TRUE/FALSE
SOME BACTERIA & CRYSTALS can be NORMAL IN URINE
TRUE
4 possible findings for ACUTE RENAL FAILURE in horses?
- LARGE, SWOLLEN kidneys
- CASTS in URINE SEDIMENT
- ENZYMURIA (GGT in urine)
- often GOOD RESPONSE TO TREATMENT
what medication can PREDISPOSE a horse to CHRONIC RENAL FAILURE?
LONG-TERM NSAIDs
3 possible findings for CHRONIC RENAL FAILURE in horses?
- SMALL, IRREGULAR KIDNEYS
- HYPERCALCEMIA
- POOR RESPONSE TO TREATMENT
what is a KEY diagnostic in determining if a HORSE is in ACUTE or CHRONIC renal failure?
THEIR RESPONSE TO TREATMENT
IF GOOD = LIKELY ACUTE
IF POOR = LIKELY CHRONIC
what 4 things can cause ACUTE RENAL FAILURE?
- AMINOGLYCOSIDES
- NSAIDs
- EXERTIONAL RHABDOMYOLYSIS can produce PIGMENT & STOP UP TUBULES & KILL THEM
- VASOMOTOR NEPHROPATHY
–> depending on TONE of AFFERENT & EFFERENT ARTERIOLES to facilitate AUTOREGULATION
–> if this DOESN’T WORK, can cause RENAL HYPOPERFUSION –> AKI
MYOGLOBINURIA can indicate WHAT DZ?
ACUTE EXERTIONAL RHABDOMYOLYSIS
3 examples of AMINOGLYCOSIDES?
3 examples of NSAIDs in HORSES?
both of these can cause…
AMINOGLYCOSIDES
1. GENTAMYCIN
2. AMIKACIN
3. OXYTETRACYCLINE
NSAIDs
1. PHENYLBUTAZONE
2. FLUNIXIN
3. KETOPROFEN
both can cause ACUTE RENAL FAILURE
what is the most COMMON PATHOLOGIC FINDING/CAUSE of ACUTE RENAL INJURY?
what other 3 clinical findings can we have in ACUTE RENAL INJURY?
ACUTE TUBULAR NECROSIS
other 3?
1. CASTS on URINE SEDIMENT
2. ENZYMURIA = high URINE GGT
3. MICRO-HEMATURIA = urine LOOKS NORMAL but POSITIVE FOR BLOOD ON DIPSTICK & UA
PAPILLARY NECROSIS…
= definition
commonly occurs after…., especially when…
causes what 2 things?
can PRE-DISPOSE horses to…
= necrosis of RENAL PYRAMIDS
commonly occurs after NSAID ADMINISTRATION (BUTORPHANOL) especially when DEPRIVED OF WATER
causes…
1. MICROHEMATURIA
2. ACUTE RENAL INJURY
can PRE-DISPOSE horses to NEPHROLITHS
a NORMAL kidney should be ~____cm ACROSS on US
if a KIDNEY is LARGER THAN THIS VALUE on US, then likely…
17
if kidney is LARGER, then AKI
ID what RED CIRCLE INDICATES
PALE AREAS IN CORTEX = ACUTE TUBULAR NECROSIS
ID what RED CIRCLE INDICATES
PAPILLARY NECROSIS = necrosis of RENAL PYRAMIDS, they become SLUDGE in this image
describe HISTOLOGIC finding here
CHRONIC NECROSIS & INFLAMMATION in kidney causes LOST NUCLEI
how do we FIX ACUTE RENAL FAILURE? (trick question)
WE CANNOT! RENAL TUBULAR CELLS have to REGENERATE on their OWN
2 goals for TREATING ACUTE RENAL FAILURE?
- STOP the patient from GETTING WORSE while RENAL TUBULAR CELLS HEAL/REGENERATE
- MAKE PATIENT FEEL BETTER while RENAL TUBULAR CELLS HEAL/REGENERATE
3 treatments for ACUTE RENAL FAILURE?
- maintain EUVOLEMIA
–> prevent FURTHER CELL DAMAGE by MAINTAINING RENAL PERFUSION/prevent renal hypo perfusion - DIURESIS via EXTRA FLUIDS only if UREMIA needs to be corrected
- maintain ELECTROLYTE & ACID-BASE BALANCE
PROGNOSIS for ACUTE RENAL FAILURE in HORSES
HIGHLY VARIABLE
if a horse is ISOSTHENURIC, why will we see WEIGHT GAIN?
if ISOSTEHNURIC, then likely RENAL FAILURE & CANNOT DIURESE EXTRA FLUID, so likely EDEMA CAUSED WEIGHT GAIN
ID pathology on US of KIDNEY
NEPHROLITH
ID arrows & the TWO BOTTOM (both are the same)
ARROWS = NEPHROLITHS
BOTTOM = ACOUSTIC SHADOWING from minerals
ID pathology
HYDRONEPHROSIS
ID in kidney
URETER
ID big ANECHOIC structure in KIDNEY
HYDROURETER
ID pathology
NEPHROLITHS in BOTH KIDNEYS
ID pathology
URETEROLITH
definition of POLYURIA in horses?
definition of POLYDIPSIA in horses?
POLYURIA in horses = > 50 mL/kg/day URINATED
POLYDIPSIA in horses = > 100 mL/kg/day DRANK
4 common DDxs for PU/PD in horses? how to rule in/out?
- RENAL = RENAL FAILURE
–> CBC/chem, UA - ENDOCRINE = CUSHING’S/PPID, DIABETES INSIPIDUS (not responding to ADH)
–> PPID = ENDOGENOUS ACTH, TRH stim
–> DI = water deprivation test or ADH response test - PSYCHOGENIC = horse is bored & drinks often
–> water deprivation test - others = RARE
do horses get DIABETES MELLITUS?
EXTREMELY RARE TO NO
WATER DEPRIVATION TEST..
usually used to test for WHAT disease & based on WHAT clinical sign? what ALTERNATIVE test could you run for this disease?
what OTHER disease could this test for?
when should this test NOT be run?
usually used to test for DIABETES INSIPIDUS, PU/PD
can alternatively do an ADH-RESPONSE test
could possibly test for PSYCHOGENIC causes of PU/PD
this test SHOULD NOT BE RUN IF PATIENT IS ALREADY AZOTEMIC
if we see PROTEINURIA, what PART of the kidney is likely diseased?
the GLOMERULUS
what 2 bloodwork findings are nearly DEFINITIVE for RENAL DZ in horses?
- AZOTEMIA
- ISOSTHENURIA
would you expect to see AZOTEMIA in PSYCHOGENIC causes of PU/PD?
NO, DRINKING A LOT WOULD NOT LEAD TO AZOTEMIA
if urine has a “PORT WINE” color, what is the TOP DIFFERENTIAL?
what is another term for color in urine?
on urine dipstick, will come up positive for ____, so ____URIA; therefore this horse also has ____ _____
TOP DDX = EXERTIONAL RHABDOMYOLYSIS
another term = PIGMENTURIA
on urine dipstick, will come up positive for HEME so HEMOGLOBINURIA; therefore this horse also has INTRAVASCULAR HEMOLYSIS
what is the MOST COMMON cause of INCONTINENCE in horses?
what are the 2 sub-categories?
MOST COMMON CAUSE OF INCONTINENCE = NEUROGENIC
can be UPPER MOTOR NEURON or LOWER MOTOR NEURONS affected
POLYNEURITIS EQUI..
etiology?
= what occurs in this disease?
can SOMETIMES also affect…
what do we see on PE & why? (3)
how is it DIAGNOSED? (2)
treatment/prognosis?
etiology = IDIOPATHIC
what occurs? = INFLAMMATION of NERVES especially the DISTAL SPINAL CORD
can SOMETIMES also affect CRANIAL NERVES
on PE…
1. animals CONSTANTLY DRIBBLING URINE because CRYSTALS THERE
2. BLADDER feels like a DINNER PLATE on palpation
3. PARAESTHESIA/HYPALGESIA (very painful) around the TAILHEAD
diagnosis?
1. BIOPSY of SACROCAUDALIS DORSALIS LATERALIS (tailhead muscle)
2. SAND-FILLED bladder on US
NO DEFINITIVE TREATMENT & POOR PROGNOSIS
SABULOUS CYSTITIS
etiology?
this is the MOST COMMON CAUSE OF…
= definition
what does “sabulous” mean?
treatment/prognosis?
IDIOPATHIC
MOST COMMON CAUSE OF NEUROGENIC INCONTINENCE in HORSES
= IDIOPATHIC BLADDER PARALYSIS but has NO OTHER NEURO SIGNS
sabulous = SAND
NO DEFINITIVE Tx & POOR prognosis
6 DDXs under 4 categories for NEUROGENIC INCONTINENCE? (just list the names)
first 2 have 2, last 2 have 1 each
- IDIOPATHIC
–> POLYNEURITIS EQUI
–> SABULOUS CYSTITIS - INFECTIOUS
–> EHV-1
–> BACTERIAL CYSTITIS - ACQUIRED
–> TRAUMA from DYSTOCIA or PELVIC FRACTURE - CONGENITAL
–> ECTOPIC URETER
EQUINE HERPES VIRUS-1…
etiology?
can cause WHAT MAIN clinical sign? + give 3 others
contagion?
repeatability?
etiology = INFECTIOUS
can cause NEUROGENIC INCONTINENCE/URT Dz, among also…
1. FEVER
2. ATAXIA
3. ABORTION STORM
VERY CONTAGIOUS
REPORTABLE
