Renal Literature Flashcards
What may • May disrupt the widely held assumption that renal lesions from TKIs are reversible?
Masitinib induced minimal change disease and AKI (oliguria)
When assessing cats that were managed with hemodialysis, how many remained dialysis independent at 30 days?
About 42%
28% died and 30% euthanized
When assessing cats that were managed with hemodialysis, what was the most common etiology?
- 35% = Ureteral obstruction***: Survival rate: 67%
- Pyelonephritis: 57%
- Lily Ingestion: 17%
- Ethylene Glycol: 8%
When assessing cats that were managed with hemodialysis, what is known about the novel clinical scoring system?
Several models that correctly classified outcomes in 75-77% with reevaluation 84-89%
Higher scores were associated with decreased probability of survival
When assessing cats that were managed with hemodialysis, base on the novel clinical scoring system what parameters were associated positively with survival ?
Vomiting and ureteral obstruction
What is an AKI grading system that was established in dogs and cats?
Based on creatinine (need at least 2 values)
Level 0: < 1.6 and change of < 0.3
Level 1: 0.3
Level 2: >1.6 and change of >0.3
Based on the AKI grading system in dogs and cats, what could be concluded about mortality?
Increasing azotemia helps to predict mortality in dogs and cats
Dogs:
Level 1 (2 days): 3X more likely to die within 90 days
Level 2 (2, 3, 7 days): 3X more likely to die within 30 or 90 days
Cats:
Level 2 (3, 7 days): 3X more likely to die at 30 days; 4X more likely to die if within 7 days
○ At 2, 3, 7 days: 3X more likely to die at 90 days
Exception: Cats at Level 2 (day2) did not have decreased survival at 30 days
In a group of cats with AKI nonsurviving cats were noted to have what parameters?
- Lower PVC (lower RBC)
- Lower WBC
- Lower lactate dehydrogenase (LDH)
- Lower albumin
- Lower albumin/globs ratio
- Lower BG
- Reduce body temp
- Older
NOTE: BUN and creatinine were not prognostic factors (but a decrease in 3 days was significant with reduced death)
In a group of cats with AKI, what parameters were used in a prognostic index?
body temp, albumin, and LDH
Predicting death 0.86 (sen 77%/spec 90)
Based on 25 cats after ingestion of lily ingestion within 48 hrs, what showed to result in good outcomes?
GI decontamination
IV diuresis
(within 48 hours)
Based on 25 cats after ingestion of lily ingestion within 48 hrs, what was the incidence of AKI?
LOW incidence of AKI
74% had normal BUN/creat during hospitalization
9% had increased values at d/c
What is the VAKI?
It is a veterinary AKI staging system (JVECC) - Based on baseline creatinine and changes from baseline: stage 0 (S0; <150%) stage 1 (S1; 150-199% or ≥26.5 μmol/L [≥0.3 mg/dL]) stage 2 (S2; 200-299%) stage 3 (S3; ≥300%)
Based on the VAKI staging system used in 164 dogs, mortality was greater in which stages?
Mortality rate was greater for S1-3 (13/24; 54.2%) compared to S0 dogs (22/140; 15.7%)
Dogs meeting VAKI stage 1-3 criteria were less likely to survive to discharge
Based on the VAKI staging system used in 164 dogs, what are associated and NOT associated with mortality?
Associated: Stage and age
Not associated: Length of stay, anesthesia, or # diagnoses
In dogs with AKI, what disease had higher BP?
Lepto AKI
In dogs with AKI, hypertension was a common CS, how did dogs respond to amlodipine?
Amlodipine helped to reduce hypertension within 24 hours, HOWEVER, significantly lower proportion of survivors in treated compared to non-treated dogs 59% versus 83% (overall survival 73%)
Which lillies are associated with AKI in cats?
Lilium genus: Oriental, Easter, and Asiatic lilies; Hemerocallis genu: Daylilies
What is known about E. coli pyometra related nephropathy in dogs?
Results in renal dysfunction (affects glomeruli and proximal tubules) - But it is transient in most dogs (resolved 6 months after sx compared to healthy controls)
Which biomarkers were evaluated in E. coli pyometra related nephropathy in dogs?
Biomarkers that were used in urine (normalized with creatinine in sample):
• IgG (glomerular)
• C-reactive protein (glomerular)
• Albumin (glomerular)
• Retinol Binding Protein (tubular)
• Thromboxane B2 (intrarenal and glomerular filtration)
• NAG (tubular)
What are shown in cats with reduced renal mass (sx) and the effects on GFR with meloxicam and aspirin?
Neither has an effect on GFR (urinary clearance of exogenous creatinine, serum creatinine, or UPC)
Which NSAID may be used in dogs with CKD (IRIS stage 2-3) with OA?
Tepoxalin (Zubrin) - Monitoring is needed
No changes in chemistry, UA, UPC, uNAG, iohexol plasma clearance, or BP
What was noted in healthy dogs that were administered COX-2 selective NSAIDs (carprofen and etodolac) in combination with lasix?
Reduced GFR and transient impaired renal function
What is hyperchloremic metabolic acidosis
with a normal anion gap in the face of an urinary pH of
7 suggestive?
Distal Renal Tubular Acidosis
Which infectious dz in a dog has been noted to result in a distal RTA?
Lepto
hyperchloremic normal anion gap metabolic acidosis with alkaline urine that was consistent with a diagnosis of distal renal tubular acidosis
What are noted in UPC for dogs with pyometra?
Significantly higher UPC with pyometra than healthy age matched controls
27/47: UPC >0.5
12/47: UPC >1
7/47: UPC >2
What are noted in renal bx from dogs with pyometra?
Glomerulosclerosis and tubulointerstitial nephritis were common kidney biopsy findings in proteinuric dogs with pyometra. Dogs with glomerulosclerosis (5/10), either global or focal and segmental, had UPC>1.0 at ovariohysterectomy and afterward.
Which nephron segment is involved with the following biomarker: albumin?
Glomerulus and proximal tubule
Which nephron segment is involved with the following biomarker: IgG and IgA?
Glomerulus
Which nephron segment is involved with the following biomarker: Retinol-binding protein?
Proximal tubule
Which nephron segment is involved with the following biomarker: B2-Microglobulin
?
Proximal tubule
Which nephron segment is involved with the following biomarker: a1-Microglobulin
?
Proximal tubule
Which nephron segment is involved with the following biomarker: Cystatin C
?
Tubular Cells
Which nephron segment is involved with the following biomarker: N-acetyl-b-D-glucosaminidase (NAG)
?
Proximal >distal tubule
Which nephron segment is involved with the following biomarker: Gamma-Glutamyltransferase (GGT)?
Proximal tubule
Which nephron segment is involved with the following biomarker: Lactate dehydrogenase?
Proximal >distal tubule
Which nephron segment is involved with the following biomarker: Tamm-Horsfall protein?
Distal tubule
What are considered Intermediate/High MW proteins as urine biomarkers?
Albumin
IgG
IgA
What are considered Low MW proteins as urine biomarkers?
Retinol-binding protein
B2-Microglobulin
a1-Microglobulin
Cystatin C
What are considered tubular enzymes as urine biomarkers?
N-acetyl-b-D-glucosaminidase (NAG)
Gamma-Glutamyltransferase (GGT)
Lactate dehydrogenase
Alkaline phosphatase
What are considered tubular proteins as urine biomarkers?
Tamm-Horsfall protein
Kidney Injury Molecule-1 (KIM-1)
Liver-type Fatty Acid Binding Protein (LFABP)
What are inflammatory proteins as urine biomarkers?
Interleukin-2, -8, monocyte chemoattractant protein-1, keratinocyte-derived chemokine, granulocyte macrophage colony stimulating factor
What could be used to differentiate AKI from CKD in dogs with renal azotemia?
Plasma NGAL (Neutrophil Gelatinase-Associated Lipocalin)
Plasma NGAL concentration was significantly higher in dogs with AKI compared with dogs with CKD
plasma NGAL concentration >37.4 ng/mL had 65% sensitivity and 82% specificity to differentiate AKI from CKD in dogs with renal azotemia
What is NGAL?
Neutrophil gelatinase-associated lipocalin (NGAL) is released from renal tubular cells after injury and serves in humans as a real-time indicator of active kidney damage
What happens with NGAL in azotemic animals?
Serum and urine NGAL significantly higher in azotemic animals compared to nonazotemic dogs
What has been shown with NGAL in dogs with CKD?
Higher serum and urine NGAL was associated with death compared to survivors
Dogs with higher sNGAL survived a significantly shorter time
What are a better predictor of outcome in CKD dogs than creatinine?
Serum NGAL
sNGAL was 50.6ng/mL
Sen 76.9%, Spec 100%
What may be a useful prognostic marker of CKD in dogs
Serum NGAL
What is a sensitive and specific marker of AKI in the urine in dogs?
NGAL/creatinine ratio
Which urine biomarker was an indicator of AKI in azotemic and nonazotemic dogs?
NGAL/creatinine ratio
What is the IRIS AKI staging system?
Based on creatinine
Grade 1: 10
Substage:
- Non oliguric (NO) or oligoanuric (O)
- Requiring renal replacement therapy (RRT)
Which biomarkers were evaluated in an X-linked hereditary nephropathy (males)?
Urine (compared to creatinine): retinol binding protein β2-microglobulin NGAG NGAL IgG
Which urine biomarker in X-linked hereditary nephropathy correlated most strongly with increasing creatinine, decreased GFR, and interstitial fibrosis?
Urine retinol binding protein/creat
In X-linked hereditary nephropathy, what are considered predictors of GFR?
Age
Serum Creatinine
Urine IgG/creat
Urine β2-microglobulin
NOTE Urine retinol binding protein/creat!
Which urine biomarkers are increased in CKD?
Albumin, Retinol binding protein, and NAG
Is there a difference in urine biomarkers in healthy young vs old dogs?
No there is no significant difference detected with age
What urine biomarker has been predictive of geriatric cats developing azotemia?
Urinary auxin-to-creatinine concentration ratio (higher ratio in cats that later developed azotemia)
BUT no relationship btwn UC/C and plasma creatinine
What urine cytokines have been noted in CKD cats?
Significantly higher IL-8, TGF-B1; lower VEGF
Positive correlation of creatinine with TGFB1 in urine in CKD cats
Despite normal cholesterol levels in dogs with CKD, what is seen?
Dyslipidemia was consistently found in dogs with CKD and Nephrotic syndrome
(Decreased in HDL and variable increased in LDL and VLDV ) - similar to in people
What is different btwn dogs with CKD and nephrocit syndrome in regards to dysplipdemia?
Nephrotic syndrome dogs have proportionately greater increase in VLDL compared to dogs with CKD
In a study in the UK in CKD dogs, what are significantly associated with death and what was the MST?
IRIS stage and BUN significantly associated with hazard of death in CKD dogs
MST: 226 days from dx
In a study in the UNk in CKD dogs, what are the significant risk factors of the dz?
Age
Insurance
Breeds (Cocker, CKSC)
What is the prognosis of azotemic dogs with pulmonary changes?
No association of pulmonary change or dysfunction in azotemic dogs was noted to affect the prognosis
What has been noted to be associated with significantly improved survival in CKD dogs?
Higher BCS!!!
What derangements in Ca-P are noted in CKD?
Hyperparathyroidism and hyperphosphatemia (even in early stages of CKD) noted!!
What range of phosphorus correctly identified presence of hyperparathyroidism in dogs with CKD?
serum phosphorus concentration in the 4.5-5.5 mg/dL
What is true about CKD dogs with CaXPhos product >70?
Negative prognostic factor in CKD dogs
Mortality higher in dogs with CaXPhos>70, risk of death 4.2X as high as risk of death if <70
What is found to be increased in cats with CKD?
SDMA (serum symmetric dimethylarginine) -
Increased SDMA = Decreased GRF (reciprocal), similar relationship of creatinine to GFR
Linear correlation btwn SDMA and creatinine
Which biomarker in CKD cats allows for earlier detection of CKD compared to serum creatinine?
SDMA (serum symmetric dimethylarginine)
Increased before serum creatinine in 17/21 cats
Correlated with creatinine and decreased GFR
What is known about KIM-1 in cats?
KIM-1 (3 variants): Found in urine of cats with AKI (not CKD cats)
Histopath - Revealed KIM-1 in tubular cells
Indicator of tubular injury*
What is the MOA of chinese rhubarb?
Antifibrotic effects dt inhibition of TGF-B (fibrosis with kidney dz)
What did the use of chinese rhubarb show in cats with CKD?
Based on creatinine, BW, HCT, UPC, BP = NO significant difference in progression of CKD bwtn chinese rhubarb, benazepril, or both
What is known about uremic gastropathy in CKD cats?
NO ulcerations!!! Gastric fibrosis (43%) and materialization (38%) most common!!!
Lesions were more likely in CKD cats then controls
What is known about gastrin levels in CKD cats?
Gastrin is significantly higher in CKD cats BUT NOT associated with gastric ulceration
What method can be used in cats to determine ECF volume?
Intercept iohexol clearance
(standard bromide dilution)
Best standardized by body surface area
Explain the ECF volume in normal cats and those with mild CKD (creat about 2).
No difference btwn azotemic and nonazotemic cats in ECF volume
What has been shown to reduce FGF-23 concentrations in CKD cats?
Feeding a renal diet (phosphorus restriction)
Reductions in plasma FGF-23 in hyper- and normophosphatemic cats with stable azotemia CKD - Dietary phos restriction may enable cats to maintain normal phos
This group also had lower phos, PTH, and FGF-23 compared to CKD cats feed normal diet
Is there a single sample method for determining GFR in cats?
Yes! Modified Jacobsson method provides accurate estimation of iohexol clearance in cats, from a single sample collected at 180 minutes postinjection and using a formula based on the body weight to predict ECFV
(compared to iohexol clearance, multisamples)
Doese feeding a high salt diet affect renal function in older cats?
NO! GFR, BP, and other variables were not affected by dietary salt intake over two years
In controls:
Higher aldosterone
Lower Urinary Na/creat ratio
(UNKNOWN IN CKD CATS)
What does FGF-23 do in CKD cats?
FGF-23 plasma concentrations increased with increasing IRIS CKD stage in cats
Higher in cats that have higher phosphorus (based on stage of CKD)
What were predictors of FGF-23 levels in cats with CKD?
Independent predictors: Phosphate Log creatinine Total Calcium Log PTH PCV
In a group of geriatric cats, what was predictive of development of azotemia?
FGF-23 concentrations (significantly increased in cats that developed azotemia compared to cats that did not develop azotemia over the 12 months)
Positive relationship btwn FGF-23 and PTH (suggestive of association with renal secondary hyperPTH)
What is an effective treatment for anemia in CKD cats?
Darbepoetin (1ug/kg/wk, also give iron)
56% responded by reaching target PCV (25%)
MST responders: 238 days compared to MST nonresponders 83 days
What side effects were see in darbepoetin given in cats with CKD?
vomiting, hypertension, seizures, and fever
In 213 cats with CKD followed for a year, what was noted within progressive to CKD?
ONLY 47% progressed within 1 year and it most it was SLOW
In 213 cats with CKD followed for a year, what was predictive of progression in azotemia?
High phosphate
High UPC
(HCT at some stages)
What is the effect of CKD on clearance and bioavailability of mirtazapine in cats?
Delays clearance and bioavailability in CKD cats compared to age matched controls
= 1.88mg PO q48hrs is recommended in CKD cats
What is a potential consequence of vaccination with feline herpesvirus 1, calicivirus, and panleukopenia (FVRCP) vaccines in cats?
Development of annexin A2 and alpha-enolase antibodies (which are associated with autoimmune dz in humans)
What is known about PTH levels in geriatric cats?
PTH significantly increased in cats that developed azotemia over the study (1 year) compared that those that were nonazotemic
PTH changed before increasing in phosphorus or Ca
Which infectious disease has been noted in cats in Australia with CKD?
FIV
Among cats < 11 years of age, those with CKD were significantly more likely to have positive test results for serum antibodies against FIV gp40 than were cats without CKD
What concurrent disease was significant in cats?
Significant concurrence between CKD and DJD in cats of all ages, indicating the need for increased screening for CKD when selecting DJD treatments
What can be used in dialysis catheters that has bad flow?
Alteplase (tissue plasminogen activator)
Effective but effects SHORT lived
What were complications seen with peritoneal dialysis in cats?
dialysate retention and sequestration of dialysate SC`
What 3 diseases have the impact on proteinuria management in dogs?
amyloidosis, immune complex-mediated glomerulonephritis (ICGN), and non-ICGN
What is recommended for first choice tx in dogs with peracute or rapidly progressive glomerular dz with IM pathogenesis?
Mycophenolyate +/-steroids
Cycylophosphamide can be considered too
What is recommended in dogs with active but stable or slowly progressive glomerular dz within IM pathogenesis?
Mycophenolayte
Chlorambucil and Azathioprine
Cyclophosphamide + steroids
Cyclopsorine
What was seen in dogs with PLN on TEG?
Hypercoagubility (low K, High alpha, high MA, and high G) compared to controls
BUT did not correlate with antithrombin, albumin, or UPC
What mutation likely causes autosomal recessive hereditary nephropathy in English Springer Spaniels?
COL4A3 and COL4A4 reduced
COL4A4 substitution that results in premature stop codon
In dogs that have nephrotic syndrome, what is associated with poor prognosis?
Nonazotemic glomerular disease
51 days compared to 605 days in glomerular dz dogs but no nephrotic syndrome
With renal amyloidosis, which animals had hypoalbuminemia, worse elevation in creatinine, nephrotic syndrome, renal medullary amyloidosis?
Hypoalbuminemia: 100% other, 64.7% Shar Pei
Serum creat: 3 times higher in Shar Peis than others
Nephrotic syndrome: 10% other and NOT in any Shar Peis
Renal medually amyloidosis:
100% Shar Pei , 49% other
In dogs with renal amyloidosism, what is negatively associated with survival?
Serum creatinine
What drug can be used with refractory proteinuria?
Angiotensin II subtype 1 (AT1) receptor antagonist, telmisartan
What is known about feeding a renal diet to dogs with proteinuria but that are NOT azotemic?
Feeding a renal diet combined with benzapril to non-azotemic dogs with renal proteinuria may improve proteinuria and SBP control compared with the administration of maintence diet and benzapril without causing significant clinicallydetectable malnutrition
What are concluded from retired racing greyhounds and microalbuminuria?
Hypertension is common in RRG (62%)
Microalbuminemia was more common in hypertensive animals (84%) compared to non-hypertensive (18%)
However, renal bx revealed mild renal changes
What can help to reduce biofilm on u caths in dogs?
Chlorhexidine sustained release varnish-coated u cath
What was shown in a Randomized, double-blinded, placebo-controlled clinical trial comparing short duration TMS and long duration beta lactam in female dogs with uncomplicated UTIs?
No difference in cure rate bwtn short duration TMS (3 d) and long duration Beta lactam (cephlexin, 10 d)
Long term cure rate in BOTH groups were LOW!!! Maybe not so uncomplicated….
What is known about the vaginal microbiota in FS dogs with recurrent UTIs and control FS dogs?
There is NO difference in vaginal microflora
Most common E, coli and Staph pseudintermedius
Based on a study of vaginal microflora in dogs, what was the most common lactic acid producing bacteria noted?
Enterococcus canintestini
Only noted in 7/44 dogs (2 from UTI group and 5 from controls)
What is known about using a catalase-based urine test to detect UTIs in dogs/cats?
Negative Uriscreen helps exclude UTI
BUT…… 11% False negative and 24% false positive
Means that a UC is still needed to exclude or confirm UTI in ALL cases
What are the effect of administration of an oral probiotic on lactic acid producing bacteria in vaginal vault of normal dog?
Oral probiotic for 14 day and 28 days did NOT increase prevalence of vaginal lactic acid producing bacteria
These bacteria are VERY uncommon in vaginal flora of dogs (Enterococcus canintestini) was the most common (NOT in the probiotic)
Based on a prospective, multicenter, controlled, randomized blinded clinical trial, is there a difference btwn high dose - short duration enrofloxacin and conventional Clavamox for uncomplicated UTIs in dogs?
NO! High dose - short duration enrofloxacin was NOT inferior to conventional Clavamox (14 d) and thus could be considered an option in dogs with uncomplicated UTIs
What has been found in IVDD nonambulatory dogs and UTIs?
High prevalence of UTIs = MANY were occult
These dogs need to be monitored for UTIs post-op, UC even if negative sediment
In what sex and breed are urethral plugs common?
Male dogs (esp PUGS)
83% struvite plugs
What are the effect of intravesical alkalinized lidocaine (3 days) in LUTD cats?
No benefit (in recurrence rate or CS severity)
NOT blinded
Which infectious dz has been noted in the urine and serologic exposure in FIC cats?
Feline Calicivirus
What less invasive procedure can be used for idiopathic renal hematuria?
• Endoscopic guided sclerotherapy (silver nitrate) - placement of a stent
Cessation of macroscopic bleeding 4/6 dogs (about 6 hrs)
What should be considered a DDx for cats that are progressive azotemic several months after renal transplant?
Retroperitoneal fibrosis
Is there a difference in UPC from free catch vs cysto methods?
No significant diff! Methods classified dogs the same
Is there a difference in culture rate when animals are given ABX at induction vs after sample collection during a cystotomy?
NO! No difference in culture results (+ or bacterial type) if ABX given at induction vs after sx culture collected in dogs undergoing cystotomy for cystic removal
Was the type of urine collection system (open (sterile IV bags) vs closed) associated with likelihood of developing nosocomial bacteriruia?
NO! Not associated
What bacteria results in encrusted cystitis and what tx options are available?
Corynebacterium and Stap pseudintermedius) - can be tx with dissolution diet and ABX (instead of sx derbidement)
What is known about subclinical bacteriruia in female dogs?
Prevalence 8.9%
Nonprogressive condition in healthy female dogs (persistent or transient)
No dogs developed CS during 3 month study
No difference in prevalence with age (young/middle vs old)
What is the giant kidney worm?
Dioctophyme renale
What is known about using the urine dipstick paddle to detect UTIs in dogs/cats?
Sen 97.3%, Spec 98.6%, path ID was NOT accurate
• If growth is noted on the paddle = UC should be submitted
What is the classic signlament for urate stones in cats?
Purebred, neutured, 4-7 yrs, with uroliths in bladder or urethra (no conclusion on cause/effect
What are potential risk factors in dogs with struvite uroliths?
Toy/small breed, FI more common
• More common if urine: Basic pH, RBCs or WBCs+, protein >30 mg/dl, ketones >5 mg/dl
In regards to sterile struvite uroliths in cats, what method is good for dissolution?
Diet! 13 days with S/D (better than c/d)
How did Laparoscopic-assisted cystotomy compare to open cystotomy?
- Laparoscopic-assisted cystotomy was more time-consuming and expensive but associated with fewer postoperative doses analgesics (IV) compared with open cystotomy
* No difference in days in hospital, or prevalence of incomplete removal
What can be used to allievate urethral obstruction with TCC in dogs?
- Self expanding nitinol urethral stents successful to alleviate TCC induced obstruction
* MST: 78 days, Complications: 7/18 incontinent, 3 reobstructed with TCC, 1 reobstructed after procedure, 2 stent migration; 16/17 owners happy
What is a good low cost option for urethral obstruction in male cats?
Drugs (ace, buprenorphone, medetomide), decompressive cysto, SQ fluids, and low stress environment
11/15 cats unobstructed within 72 hrs
What are risk factors for recurrent obstruction in cats?
Older cats higher risk
• Longer duration catheterization, increasing water at home = lower probability of recurrence
When looking at cats at 24 hrs and 30 days, what are associated with lower rates of feline ureteral reobstruction?
- 24 hrs and 30 days: Lower rate with prazosin (7-18%) vs phenoxybenzamine (21-39%)
* 24 hrs: Lower rates with 3.5F (6.67%) compared to 5F (18.97%) urinary catheter\
What % of dogs remained continent after cystoscopic guided laser ablation of intramural ectopic ureters (females)?
- 47% No additional tx to remain continent
* 16 remained incontinent but improved with med management, bulking injection, or hydraulic occluder
* Overall urinary continence rate of 77%
* All dogs had concurrent urinary anomalies
What % of dogs with vestibulovaginal septal remnants had ectopic ureters?
83%
In a population of FS dogs what was the prevlence of acquired urinary incontinence?
LOW, 5.12%
Not related to age at OHE
But larger dogs (>15 kg) 7X more likely to have incontinence than small dogs
What had a negative effect on the linear correlation btwn urine osmolality and USG in dog urine?
Ketones
What values allowed one to detect overhydration prior to CS in beagle dogs?
Ultrasound of renal arterial resistive index (1hr) and pulsatility index (2hrs) significantly decreased prior to detection of CS of overhydration in beagle dogs
What was the prevalence of circumcaval ureters in cats at an animal shelter?
- Circumcaval ureters in 35.2% of cats at animal shelter (301)
* Right 92/106; left 4/106; both 4/106
* Mean right kidney length significantly greater than left with right circumcaval ureters
What is the proposed cause of circumcaval ureters in cats?
Related to caudal vena caval developement
Many had a double caudal vena cava
T/F. Plasma iohexol and creatinine clearance can be used interchangeably for screening patients with CKD
True
BUT large difference may exist for dogs with GFR within or above RR
Which drugs can be used without affecting GFR measured by dynamic CT in dogs?
Etomidate
Propofol
Thiopental
Maintained on isoflurane
In sexually intact dogs, what can semen affect on the urine dipstick?
Protein and RBCs can be falsely +
What is true of proteinuria if USG 1.012 and urine dipstick 1+?
If USG 1.012 - Likely nonproteinuria
What is the best diet for urinary undersaturation for CaoX?
Alkaluria
No changes in URSS with struvites and the different diets
Is there an affect on bone density an calcium levels in cats that are feed acidifying diets?
NO! AT least in healthy cats feed for 12 months
What did feeding a CaOX prevention diet to cats result in their urine that will reduce growth and aggregation of CaOX?
Increased urine GAGs (glycosaminoglycans, glycoproteins that are inhibitors of growth and aggregation of CaOx stones)
• No effect of diet on urine Tamm-Horsfall or 4 isoforms of nephrocalcin
Which mutation is associated with hyperuricosuria in Bulldogs and Black Russian Terriers?
Hyperuricosuria dt homozygous SLC2A9 Cyc18 mutation
• Estimated 3% Bulldog and 27% Black Russian terriers are hyperuricosuria
§ Need DNA testing to select again mutation
Which imaging modality results in an overestimation of cytolith size?
US!! OVERESTIMATED! (68% overestimated cytolith size)
No difference in plain rads, double contrast cysto, or CT
What is a better fluid choice for uretheral obstruction in cats?
LRS was more efficient in restoring acid-base and electrolyte balance in severely decompensated cats with urethral obstruction (occlusion of u caths) compared to 0.9% saline
What was seen with acoustic startle reflex in cats with FIC compared to controls?
- Magnitude of acoustic startle reflex in cats appeared sensitive to environmental conditions (lower if habituated, at least in females) and sex (decreased in neutered animals) in healthy and FIC cats
* Higher acoustic startle relfex in cats with FIC vs healthy cats
EXCEPT: FIC cats with environmental enrichment
What could serve as a potential biomarker for FIC?
Urine fibronectin
What effect did NAG (glucosamine) haev on FIC cats?
Increased plasma GAG in FIC cats after 21 days
Overall FIC cats had lower GAG:creat in urine compared to controls
What did cystometrograms and urethral pressure profiles show in FIC cats?
- No evidence of overactive bladder (drugs to target this are not justified)
* High maximum urethral closure pressure in FIC cats = Suggests that alpha1 antagonists or skeletal muscle relxants may be useful in this disease
* Further studies are needed
In male cats with urethral obstruction is there an association with temp or length of hospitalization?
NO!
• No association with rectal temp or length of hospitalization
• Azotemia was associated with longer hospitalization
BUN/creat higher in hypothermic group compared to normothermic group
How does the gram stain compare to urine sediment for identifying bacteria in urine?
- Gram stain was highly sensitive (96% vs 76%) and specific (100% vs 77%) at identifying bacteruria compared to urine sediment
* PPV: 100% (vs 83%)
NPV: 93% (vs 69%)
What were dogs with albuminuria more at risk for?
DEATH
How well do UC and mucosal bx culture agree?
- Significant agreement btwn UC and mucosal bx via cystoscopy
* Both negative 66%, both positive 17%, disagreement 17%
* Not statically significant, more mucosal samples than UC were + for E. coli
Suggests that if a UC is + do not need to get mucosal bx, but if you have a negative UC and consistent CS this would be a great time to get mucosal culture
What is the conclusion about neutering and risk of urinary incontinence in dogs?
- Systemic review of OHE on risk of urinary incontinence (Cochrane style)
* 7 studies that looked at it; 4 at high risk for bias
* Remaining 3 studies: Some weak evidence that neutering, particularly before 3 months of age, increased risk of urinary incontinence
* Overall: Evidence is NOT consistent nor strong enough to make firm recommendations on effect of neutering or age at neutering on risk of urinary incontinence
How many cavitary lesions in the dog prostate contain urine?
- In dogs, 18.4% of prostatic cavitary lesions that contained urine (16/87)
* Measurement of creatinine within prostatic cavitary fluid helped to dx presurgerical intra prostatic urethral fistulation (tended to required sx compared to percutaneous drainage)
What is the effect of feeding a high protein diet to renal parameters in normal cats?
- In healthy cats (feed high protein diet vs low protein diet): BUN, albumin, ALT, USG significantly higher (creat and phos lower) in high protein diet compared to low protein diet
* BUT No values were outside RR!
What is known about UTIs in cats with CKD?
• 87% had + UC, E. coli most common, susceptible to clavamox
• 18/25: Occult UTIs = More likely to be older female cats
§ No association with severity in azotemia, no effect on survival
IN male cats with obstructive FLUTD that are catheterized, how many developed bacteruria?
1/3 cats developed significant bacteruira during catheterization
In cats with MDR E. coli, what was the major risk factor identified?
If ABX has been given in past 3 months
What is known about post obstructive diuresis in cats?
- Post obstructive diuresis seen in cats after urethral obstruction
* 46% cats within first 6 hours
More likely in cats with venous pH
What factor were found more often in obstructed males with FLUTD?
• 64 cats with FIC: Risk factor of house move
• More likely in obstructed male: Pyuria, hematuria, increased UPC, struvites
§ Urethral plugs may play a role
What is known about male dogs with ectopic ureters?
- 16 Male Dogs with Ectopic Ureters: Similar to females in terms of breed, CC, age, and bilateral nature
* After sx, urinary continence in 82%
What factors in female dogs with ectopic ureters are not significantly associated with post-op incontinence?
Intra vs extra, Left vs right, unilateral vs bilateral, hydroureter, or UTI were NOT significantly associated with post-op incontinence
Name 5 tubular proteins that are biomarkers.
Made by brush border or cytosplasma of proximal tubular cells (increased release with damage)
- GGT
- NAG
- Tamm-Horsfall Protein
- KIM-1
- Fatty Acid Binding Protein (FABP) - Liver type
What is the location of GGT?
Proximal renal tubule
Urine
Used for nephrotoxicity in gentamicin
What is the location of NAG?
Proximal renal tubules (lysozymes)
Urine
uNAG: creat ratio: Increased 12 hrs to 4 days prior to creatine
What is the location of Tamm-Horsfall proteins?
Thick ascending LOH
Urine
Checking for ischemic damage
What is the location of KIM-1?
Kidney Injury Molecule-1
Proximal tubules
Increased within 12 hours, Upregaulted in AKI
Name two surrogates for GFR?
Creatinine
Cystatin C
What factors can affect creatinine?
Non linear relationship with GFR
Proprotional to patient muscle mass
Influeced by pre and post renal azotemia and hydration
BReeds that have increased muscle mass (boxerd, greyhounds, sled dogs, birmans)
What is the location of NGAL?
Neutrophil gelatinase associated lipocalin
urine, plasma, serum
Tubular damage = inflammatory protein
Unregulated rapidly after AKI (within 3 hrs)
But not specific
What is the location of IL-18?
Constitutively expressed in distal tubules
Urine
Increased that proceeds creat by 1-2 days
What is the location of B2 microglobulin?
All nucleated cells Freely filtered and resorbed in prox tub Urine (plasma) Early marker of tubular dysfunction, proceeds creat by 4-5 days VERY unstable in urine
What is the location of a1 microglobulin?
Made in liver Freely filtered and resorbed in prox tub Urine Early marker of tubular dysfunction Very stable in urine Altered by liver dz!!
What is the location of retinol binding protein?
Made in liver Freely filtered and resorbed in prox tub Urine Early marker of tubular dysfunction Wide individual variation (esp with feline CKD and hyperT4)
What is the location of cystatin-C?
Nucleated cells
Freely filtered and resorbed in prox tub
Urine = Prox tub dysfunction
Serum = Decreased GFR
What is the location of FABP?
Fatty acid binding protein (liver type)
Release from prox tubule
Urine
Elevated in multiple dz: CKD, IgA, DM, contrast
What are the new stages of CKD?
At Risk (D: 5; C: >5)
What % of animals with CDK have hyperPTH?
Cats: 84%
Dogs: 76%
What is the initiating factor of hyperPTH?
Phos (also associated with survival in CKD dogs/cats)
What are the roles of FGF-23?
made in osteoclasts
Regulate phos in tubules, calcitriol synthesis, decreased PTH production
Can renal hyperPTH be found in animals with normal Ca and Phos?
YES!!
Calcium oxalate: Urine pH and Breeds
Jagged edges
Acid to neutral
Male (>70%)
Bichon, Lhasa, Schnauzer, Pomeranian, ShihTzu, Yorkie
Calcium oxalate: Predisposing factors
Hypercalciuria (1. absorptive hypercalciuria, 2. renal-leak hypercalciuria, 3. resorptive hypercalciuria), Hyperoxaluria (probably not), hypocitraturia (citrate complexes with Ca), lack of nephrocalcin (made in proximal renal tubular cells and thick ascending limb)
Calcium oxalate: Treatment
- Increase water intake
- Avoid high oxalate foods (tofu, soy beans, sardines, sweet potatoes, asparagus)
- Do not restrict dietary phosphorus (will cause increased calcitriol formation and more calcium resorption)
- Increase potassium content can cause less Ca excretion in urine and will form potassium oxalate crystals
- Increase citrate for form Ca-citrate (soluble)
- Avoid supplementing Vit C (oxalate), Vit D (abs Ca)
- Vit B6 deficiency promotes formation of oxalate
What is the reoccur rate for CaOx?
50% within 3 years
Struvite: Urine pH and Breeds
Alkaline
Large, smooth, staghorn
Female (>85%). Min. Schnauzer, ShihTzu, Yorkie, Pug, Labrador, Dachshund
Cocker Spaniels - Sterile Struvites
Struvite: Predisposing factors
UTIs caused by urease-producing organisms (Staph, Proteus, Pseudomonas, Klebsiella, Corynebacterium, Ureaplasma)
Urease cleave urea to form ammonia and bicarbonate –> ammonium combines with magnesium and phosphate. Bicarbonate increases urine pH –> decreases solubility of MAP crystals. Ammonium damages urothelial GAG coating –> crystals and bacteria attach to urothelium and form organic matrix.
Struvite:Treatment
- Treat infection. Continue treatment until 1 month post dillolution (as stones dissolve they release trapped bacteria)
- Stone dissolution diet –> low in phosphorus and magnesium, low protein to reduce urea formation, high salt to induce diuresis, continue diet 1 month beyond radiographic resolution
- Dissolution takes 2-3 months, if not smaller within 2-4 weeks, then should consider removal
Which breed can get sterile struvites?
Cocker Spaniel
Which breed get spontaneous xanthine stones?
CKCS
Wirehaired dachshund
Urate: Urine pH and breeds
Acid to neutral
Small, smooth, multiple, green-brown
Male (>85%), Dalmatian, English Bulldog, Miniature Schnauzer, ShihTzu, Yorkie
Spontaneous xanthine: Cavalier King Charles and Dachshunds
Urate: Predisposing Factors
Dalmatian: Defect in urate transport, lower levels in hepatocytes, but also lack proximal tubular reabsorption following glomerular filtration (simple autosomal recessive inheritance), active secretion in distal tubule (transporter defect)
Portosystemic shunts (or other sever hepatic dysfunction): due to hyerammonuria and hyperuricuria (can’t convert ammonia to urea and uric acid to allantoin) Bulldogs and black Russian Terriers have same mutation as Dalmatians
Urate: Treatment
- Diet low in organ meat (low purine) reduces urate excretion
- Alkalizing urine with potassium citrate
• Na HCO3 (Diminishing amount of ammonium ions that can complex with urate)
Only diet is Hill’s u/d - has very low protein and contains potassium citrate and calcium carbonate
Allopurinol: xanthine oxidase inhibitor (decreases uric acid) still need to restrict purines or will form xanthine uroliths
Cystine: Urine pH and Breeds
Acidic
Multiple, smooth, round
Radiolucent
Male (>94%), English Bulldog, Stafforshire Bull Terrier, Mastiff, Dachshund, Chihuahua, Newfoundland*****
Cystine: Predisposing factors
Normally cystine is freely filtered at the glomerulus and resorbed in the proximal tubules - in cystinuric animals the carrier proteins responsible for resorption are defective. Also lose ornithine, lysine and arginine (COLA).
Newfies have mutation in SLC3A1 gene, but not all cystinuric dogs do (same in humans)
slc7A9 - Min Pin
Cystine: Treatment
- Diet low in protein will decrease cystine excretion
- Alkalize urine with potassium citrate (Hill’s u/d)
- Drugs include:D-penicillamine, 2-MPG(mercaptopropionylglycine) or Tiopronin - a thiol-containing drug that reacts with cystine to make a more soluble compound –> bad side effects including aggression, myopathy, proteinuria, thrombocytopenia, high LE, dermatologic changes
Ca phosphate: Urine pH and Breeds
Multiple small with variable shape Alkaline to neutral for hydroxyapatite Acidic for brushite
Male (>53%), Bichon, Miniature Poodle, Pomeranian, Pug, ShihTzu
Ca phosphate: Predisposing Factors
Pure calcium phosphate are uncommon, but these may occur as a shell to struvite or calcium oxalate uroliths
Alkaline urine pH decreases solubility of hydroxyapatite, hypercaliuria and hyperphosphaturia also predispose to formation . This can be seen in animals with hyperparathyroidism (Ca-containing uroliths)
Ca phosphate: Treatment
- Removal
2. Treat parathyroid disease
Silica: Urine pH and breeds
Jackstone
Acid to neutral
Male (>92%), German Shepherd, Old English Sheepdogs, Labrador, ShihTzu, Yorkie, Rottweiler, Boxer, Bichon
Silica: Predisposing Factors
Many are pure silica, some may have struvite or oxalate layers (GSD and OES typically have pure stones)
Diets rich in plant sources of silica like rice, soybean hulls, corn gluten can cause these.
Cranberry supplementation can result in silica uroliths.
Silica: Treatment
- Removal
2. Change diet to one lower in silica
Which breeds make pure silica stones?
GDS and OES
