Carrie A. Palm

Evaluation of Neutrophil Gelatinase-Associated Lipocalin as a Marker of Kidney Injury in Dogs

BACKGROUND Acute kidney injury (AKI) is a common and often fatal disorder in dogs. HYPOTHESIS Urine neutrophil gelatinase-associated lipocalin (NGAL)/creatinine ratio is a sensitive and specific biomarker of AKI in dogs. ANIMALS Ninety-four dogs. METHODS Prospective study. Dogs were classified as follows: (1) healthy dogs, (2) dogs with lower urinary tract disorders, (3) dogs with chronic kidney disease (CKD), (4) dogs with azotemic International Renal Interest Society (IRIS) AKI Grades II-V, and (5) dogs with IRIS AKI Grade I (nonazotemic). Urinary NGAL was quantitated in each dog using an ELISA assay and concentrations were expressed as a ratio to urinary creatinine concentration from the same specimen, and designated the urinary NGAL/creatinine ratio (UNCR). RESULTS There was a significant difference in UNCR among the study groups (P < .001). Both the azotemic and nonazotemic AKI groups had higher UNCR when compared with all other groups (P < .001 for all pairs). There was a statistically significant difference in UNCR between dogs diagnosed with CKD compared with dogs with lower urinary tract diseases (P = .005) as well as between dogs with CKD and healthy dogs (P = .001). Receiver operator characteristics (ROC) analysis of UNCR as an indicator of azotemic and nonazotemic AKI had an area under the ROC curve of 0.94 and 0.96, respectively. CONCLUSIONS AND CLINICAL RELEVANCE NGAL/creatinine ratio is a sensitive and specific marker of AKI. It can be used to screen patients at risk for AKI and can be utilized to diagnose milder forms of AKI potentially earlier in the course of the disease.

Cats and calcium oxalate. Strategies for managing lower and upper tract stone disease

Practical relevance Calcium oxalate (CaOx) containing stones are among the most common of the urinary tract stones identified in cats. Risk factors Risk factors for CaOx stone formation include such things as breed, gender and diet; stress and obesity have also been hypothesized to be risk factors for this disease. Management approach A tailored, individual management strategy for preventing CaOx stone recurrence is important and should include addressing the diet, environment and any other comorbid conditions present. Increasing the cats moisture intake is one of the key mechanisms for preventing recurrence. Clinical challenges CaOx ureterolithiasis has emerged as a difficult and sometimes life-threatening problem for cats. In those cats where stones are found incidentally, periodic monitoring may be required to assess for disease progression. Interventional procedures such as ureteral stent placements are now increasingly being performed for recurrent cases or those with larger stone burdens. Periodic radiographs for more severe cases and frequent client communication can help ensure successful outcomes for cats with lower and upper CaOx stone disease. Evidence base Limited evidence-based studies are published regarding management of feline upper and lower urinary tract CaOx stone disease, making this a difficult condition to manage in some cats. Studies designed to evaluate the relationship to dietary modifications, medical management, stress, obesity and surgical techniques are warranted in cats with upper and lower urinary tract CaOx stones.

Urinary Neutrophil Gelatinase‐associated Lipocalin as a Marker for Identification of Acute Kidney Injury and Recovery in Dogs with Gentamicin‐induced Nephrotoxicity

Background Acute kidney injury (AKI) is associated with high mortality rates in dogs, which may be a consequence of late recognition using traditional diagnostic tests. Neutrophil gelatinase‐associated lipocalin (NGAL) is a protein‐induced during kidney injury that may identify AKI earlier than traditional tests. Objectives/Hypothesis To evaluate urinary NGAL (uNGAL) and uNGAL‐to‐urinary creatinine ratio (UNCR) as early markers of kidney injury and recovery in an AKI model in dogs. It was hypothesized that these markers would document AKI earlier than serum creatinine concentration. Animals Five purpose‐bred dogs. Methods Prospective study. Acute kidney injury, defined as a > 50% increase in serum creatinine concentration above baseline, was induced in dogs by gentamicin administration (8–10 mg/kg SC q8h). Blood and urine collected for biochemical analyses and uNGAL and urinary creatinine concentrations, respectively, during AKI induction and recovery. Results Acute kidney injury was diagnosed significantly earlier based on a 7‐fold increase in UNCR compared to a > 50% increase in serum creatinine concentration (day 8; range, 2–10 mg/dl vs day 16; range, 14–19 mg/dl; P = .009). During recovery, the initial decrease in UNCR preceded the decrease in serum creatinine concentration by a median of 2 days. The uNGAL changes paralleled UNCR changes, but the increase in uNGAL was triphasic; the initial peak occurred earlier than UNCR (median, day 11 versus median, day 19). Conclusions and Clinical Importance The UNCR was early marker of gentamicin‐induced AKI and its decrease documented onset of renal recovery. Additional studies are needed to validate this marker in dogs with naturally occurring renal injury.

Evaluation of Canine Pancreas-Specific Lipase Activity, Lipase Activity, and Trypsin-Like Immunoreactivity in an Experimental Model of Acute Kidney Injury in Dogs.

Background Diagnosis of pancreatitis in dogs is complicated by extrapancreatic disorders that can alter the results of laboratory tests. Extrapancreatic disorders can also affect the diagnosis of exocrine pancreatic insufficiency (EPI). The effects of acute kidney injury (AKI) on pancreas‐specific lipase activity (Spec cPL ® Test), serum lipase activity and trypsin‐like immunoreactivity (TLI) in dogs have not been evaluated. Hypothesis/Objectives Serum Spec cPL, lipase activity, and TLI concentrations will increase secondary to decreased kidney function. Animals Five purpose‐bred dogs. Methods Experimental prospective study. Gentamicin was used to induce AKI in 5 purpose‐bred dogs. Serum samples were collected for measurement of creatinine, Spec cPL, lipase activity and TLI over 60 days, during both induction of, and recovery from, AKI. Results All dogs developed and recovered from AKI. Six of 52 (12%) serum Spec cPL concentrations were increased (2 in the equivocal zone and 4 consistent with pancreatitis) in 2 of 5 (40%) dogs. Two of 51 (4%) serum lipase activity values were increased in 2 of 5 dogs. Serum TLI was increased above the reference range in 17 of 50 (34%) samples in 3 of 5 dogs. For all biomarkers, there was no consistent correlation with increases in serum creatinine concentration. Conclusions and Clinical Importance Decreased renal excretion during experimental AKI did not cause consistent and correlated increases in serum Spec cPL, lipase activity, or TLI in this cohort of dogs.

Subcutaneous ureteral bypass device for treatment of iatrogenic ureteral ligation in a kitten

CASE DESCRIPTION A 17-week-old spayed female Sphinx was evaluated after a 3-day history of inappetence, lethargy, and vomiting. Three weeks prior, the kitten had undergone routine elective ovariohysterectomy. CLINICAL FINDINGS Abdominal ultrasonography revealed moderate hydronephrosis of the left kidney, and the left ureter was tortuous and dilated from the kidney to the level of the midureter, where it abruptly tapered. No discrete cause of obstruction could be identified. Clinicopathologic analyses revealed that the kitten was nonazotemic. TREATMENT AND OUTCOME Exploratory laparotomy revealed that the distal portion of the left ureter was irregular with ill-defined margins and abundant scar tissue, likely secondary to iatrogenic ureteral ligation during the ovariohysterectomy (suture was not observed). Intraoperative antegrade pyelography confirmed complete left ureteral obstruction extending distally from the level of the midureter. A subcutaneous ureteral bypass device was placed to allow for renal decompression. No complications were encountered in the perioperative period, and the kitten recovered well after anesthesia. The kitten was discharged from the hospital 7 days after initial evaluation and continued to do well after surgery. At long-term follow-up, abdominal ultrasonography confirmed resolution of hydronephrosis and ureteral dilation. CLINICAL RELEVANCE A subcutaneous ureteral bypass device successfully allowed renal decompression in a kitten with iatrogenic ureteral ligation. A subcutaneous ureteral bypass device may be an alternative to historical surgical options in cases of unilateral ureteral obstruction and may result in a good long-term outcome.

Nephroureteral Obstructions: The Use of Stents and Ureteral Bypass Systems for Renal Decompression.

Canine and feline nephroureteral obstruction is a complex disease process that can be challenging to treat. Although the availability of various imaging modalities allows for a straightforward diagnosis to be made in most cases, the decision-making process for when a case should be taken to surgery and the optimal treatment modality that should be used for renal decompression remains controversial. In the following discussion, an overview of the perioperative management of cases with nephroureterolithiasis and nephroureteral obstruction is reviewed, with particular focus on the use of renal decompressive procedures, such as ureteral stenting and subcutaneous ureteral bypass system placement.

Percutaneous ureteral stent placement for the treatment of a benign ureteral obstruction in a Sumatran tiger (Panthera tigris sumatrae).

A 15-year-old, 113 kg intact male Sumatran tiger (Panthera tigris sumatrae) was evaluated for weight loss, polydipsia, and intermittent hematuria. The tiger was immobilized for diagnostic testing including blood work, urinalysis, and abdominal ultrasound. Laboratory testing demonstrated macro- and microhematuria, azotemia, and an increased urine protein:creatinine ratio. Abdominal ultrasound revealed bilateral ureterolithiasis as well as hydronephrosis and ureteral dilation. Ultrasonography performed 5 months later revealed worsening of the right-sided hydronephrosis and hydroureter and a decrease in the severity of dilation on the left side presumably from passage of the left-sided ureteral calculi. Nephroureteral decompression via the placement of a stent was elected. A pigtail ureteral catheter (8.2 French diameter) was placed in the right ureter via an antegrade percutaneous approach utilizing ultrasound and fluoroscopic-guidance. Following stent placement, macrohematuria resolved although microhematuria was noted in opportunistic urine samples. Five months after stent placement, the azotemia had mildly progressed, the urine protein:creatinine ratio was improved, the right hydronephrosis and hydroureter had completely resolved, and the ureteral stent remained in the appropriate position. The tiger had clinically improved with a substantial increase in appetite, weight, and activity level. Ureteral stenting allowed for nephroureteral decompression in the captive large felid of this report, and no complications were encountered. Ureteral stenting provided a minimally invasive method of managing ureteral obstruction in this patient and could be considered in future cases due to the clinical improvement and low morbidity.

Oral Hypoglycemics in Cats with Diabetes Mellitus

Diabetes mellitus is a common disease in cats. Similar to people, cats with diabetes mellitus often have type 2 disease. Oral hypoglycemic drugs can be a potential treatment option for affected cats, especially when cats or owners do not tolerate administration of injectable insulin. Several classes of oral hypoglycemic drugs have been evaluated in cats but these drugs have not been commonly used for treatment of diabetic cats. With the advent of newer oral hypoglycemic drugs, and a better understanding of diabetes mellitus in cats, further investigation may allow for better diabetic control for feline patients.

Efficacy of Two Radiologic-Assisted Prophylactic Gastropexy Techniques.

OBJECTIVE To describe the technique and clinical outcome of prophylactic percutaneous radiologic-assisted gastropexy (PRG) and radiologic-assisted incisional gastropexy (RIG) in client-owned dogs. STUDY DESIGN Prospective, nonrandomized clinical trial. ANIMALS Fourteen client-owned, large, and giant breed dogs. METHODS Four dogs underwent PRG with fluoroscopic guidance to place 2 T-fasteners into the pyloric antrum and secure it to the right body wall. Ten dogs underwent RIG, which was a modification of PRG. For RIG, the T-fasteners were first used to approximate the pyloric antrum and body wall, then a full thickness incision through the body wall was made and the pyloric antrum was sutured to the internal abdominal wall. The duration and complications of each procedure were recorded. The gastropexy was assessed by abdominal ultrasound at day 1, week 2, and week 8 postoperative and by barium gastrogram at week 8 postoperative. RESULTS No dogs undergoing PRG had a gastropexy present at week 2. All dogs undergoing RIG had ultrasonographic evidence of gastropexy at day 1, week 2, and week 8 postoperative. Gastrograms in 9/9 dogs were consistent with an intact gastropexy, appropriate gastric positioning and appropriate gastric emptying began. No major complications were noted. CONCLUSION The PRG was unsatisfactory and did not result in a permanent gastropexy. The RIG was safe and created a gastropexy that remained intact at 8 weeks postoperative. The RIG should be considered as a minimally invasive option for prophylactic gastropexy in dogs of at-risk breeds.

Treatment of a Urethral Duplication in a Dog Using Cyanoacrylate and Coil Embolization

A 3-year-old male castrated golden retriever was presented to the University of California-Davis Veterinary Medical Teaching Hospital (UCD VMTH) for evaluation of urinary incontinence. The dog had a history of urinary incontinence since 6 weeks of age; however, the incontinence had worsened during the 3 months before initial presentation to the UCD VMTH. The owners reported that the dog was able to urinate normally, with no urine stream alteration, straining or hematuria. The dog was treated with phenylpropanolamine (dose unknown) 1 year before presentation to the UCD VMTH, but this had been discontinued 3 months before his evaluation. His owners reported no other abnormal medical history, trauma or surgeries, other than a routine castration that was performed when the dog was approximately 24 months of age. On initial evaluation at the UCD VMTH, the dog was bright, alert, and responsive with normal vital parameters (temperature 101.8°F [reference range: 100.5–102.5°F]). His heart rate was 140 beats/min, and he was panting. Body weight was 40.4 kg, and he was noted to have a body condition score of 6 (on a scale of 9). On initial physical examination, his abdomen was soft and nonpainful, and his external genitalia appeared within normal limits. Rectal examination demonstrated that the palpable urethra was smooth and symmetrical and no stones or masses were palpate. The prostate was not palpable and no abnormalities were noted in other body systems. CBC and biochemistry were within normal limits. Urine had a specific gravity of 1.037, a pH of 7, 8–12 white blood cells/hpf (reference range: 0–2 white blood cells/hpf) and clusters of cocci. The urine culture yielded Staphylococcus pseudointermedius (beta-lactamase negative) and Staphylococcus intermedius. Both bacteria were sensitive to all antibiotics evaluated except that the Staphylococcus intermedius was resistant to penicillin. An abdominal ultrasound was performed and was within normal limits. Abdominal ultrasound revealed a normal urinary tract, however, only the right ureterovesicular junction was identified. While abdominal ultrasound did not reveal any abnormalities, the lifelong presence of urinary incontinence was still suggestive of a possible congenital urinary tract abnormality, and cystourethroscopy and contrast cystourethrogram were recommended. The dog was premedicated with atropine (0.03 mg/kg SC) and morphine (0.7 mg/kg SC). Anesthetic induction was performed with ketamine (3.2 mg/kg IV) and midazolam (0.25 mg/kg IV) through a cephalic vein catheter. Anesthesia was maintained with isoflurane in oxygen. The dog was placed in right lateral recumbency on a table in the fluoroscopic suite. The prepuce was clipped, prepared with sterile technique and draped. A 7.5-Fr, 67.5-cm working length, 270° deflection flexible urethroscope was introduced into the urethra. The urethroscope was passed into the urinary bladder and a complete evaluation of the urinary bladder, ureteral openings, and urethra was performed; no abnormalities were seen, and the ureteral openings were noted to be in the correct location. An 8-Fr red rubber catheter was then introduced into the urethra. The urinary bladder was filled with a 50%/50% combination of iodinated contrast and saline to ensure that the bladder was full, but not overly turgid. When the bladder was full, a retrograde contrast cystourethrogram was performed by slowly removing the urinary catheter while a continuous injection of the contrast : saline mixture was performed. The cystourethrogram revealed a tubular structure extending from the prostatic urethra and ending into a blind pouch at the level of the distal prepuce (Fig 1); a congenital urethral duplication was diagnosed as an accessory urethra was found to originate dorsally and to the left of the normal urethra. The prepuce was palpated at this point, and a soft swelling was noted that had not been previously appreciated during physical examination. From the School of Veterinary Medicine, University of California-Davis, Davis, CA (Palm, Culp); and the Sutter Health, Sacramento, CA (Glaiberman). Work completed at the University of California-Davis, Veterinary Medical Teaching Hospital. The study was not supported by a grant. This study has not been presented in abstract form. Corresponding author: Carrie Palm, DVM, DACVIM, University of California-Davis, School of Veterinary Medicine, One Garrod Drive, Davis, CA 95616; e-mail: cpalm@ucdavis.edu Submitted November 14, 2014; Revised January 6, 2015; Accepted February 4, 2015. Copyright