Background Urolithiasis is a common and often recurrent problem in dogs. Objective To evaluate trends in urolith composition in dogs and to assess risk factors for urolithiasis, including age, breed, sex, neuter status, urolith location, and bacterial urolith cultures. Sample Population A total of 10 444 uroliths and the dogs from which they were obtained. Methods The laboratory database at the UC Davis Gerald V. Ling Urinary Stone Analysis Laboratory was searched for all urolith submissions from dogs between January 2006 and December 2018. Mineral type, age, breed, sex, neuter status, urolith location, and urolith culture were recorded. Trends were evaluated and variables compared to evaluate risk factors. Results Calcium oxalate (CaOx) and struvite‐containing uroliths comprised the majority of all submissions from dogs, representing 47.0% and 43.6%, respectively. The proportion of CaOx‐containing uroliths significantly decreased from 49.5% in 2006 to 41.8% in 2018 (P = .006), with no change in the proportion of struvite‐containing urolith submissions. Cystine‐containing uroliths comprised 2.7% of all submissions between 2006 and 2018 and a significant nonlinear increase in this mineral type occurred over time (1.4% of all submissions in 2006 to 8.7% in 2018; P < .001). Of all cystine‐containing uroliths, 70.3% were from intact male dogs. Age, breed, and sex predispositions for uroliths were similar to those previously identified. Conclusions and Clinical Importance Although calcium oxalate‐ and struvite‐containing uroliths continue to be the most common uroliths submitted from dogs, a decrease in the proportion of CaOx‐containing uroliths and an increase in the proportion of cystine‐containing uroliths occurred during the time period evaluated.

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.

Background Urolithiasis is an important upper and lower urinary tract disease in cats that results in morbidity and mortality. Objective To describe trends in composition of uroliths in cats and evaluate risk factors related to age, breed, sex, urolith location, and bacterial urolith cultures. Sample Population A total of 3940 uroliths and the cats from which they were obtained. Methods The database of the UC Davis Gerald V. Ling Urinary Stone Analysis Laboratory was searched for all urolith submissions from cats between January 2005 and December 2018. Mineral type, age, breed, sex, and urolith location and culture results were recorded. Trends were evaluated and variables compared to evaluate risk factors. Results A significant decrease in the proportion of calcium oxalate (CaOx)‐containing uroliths occurred over time (P = .02), from 50.1% (204/407) of all submissions in 2005 to 37.7% (58/154) in 2018. In contrast, the proportion of struvite‐containing uroliths increased significantly (P = .002), from 41.8% (170/407) in 2005 to 54.5% (84/154) in 2018. The proportion of CaOx‐containing uroliths in the upper urinary tract was significantly higher compared to the proportion of other urolith types in the upper urinary tract. Urate‐containing uroliths were the third most common type (361/3940, 9.2%). Overall, sex and age predispositions were similar to those reported previously. Conclusions and Clinical Importance The decrease in the proportion of CaOx‐containing uroliths and increase in the proportion of struvite‐containing uroliths warrants investigation. Further education regarding the efficacy of medical dissolution of struvite‐containing uroliths is recommended.

Background Ureteral stent and subcutaneous ureteral bypass (SUB) placement are commonly used for managing ureteral obstructions. Urinary tract infection (UTI) is a recognized complication. Objectives To determine postoperative incidence of positive urine cultures in cats undergoing ureteral stent and SUB placement and to identify risk factors associated with positive urine cultures. Design Retrospective study. Animals Forty‐three cats that underwent 48 surgical events. Procedures Medical records were reviewed. Cats were included if urine cultures were performed before and after surgery. Variables were compared to identify risk factors. Results Urine cultures were positive postoperatively pre‐discharge in 5/20 (25%) cats. Median duration of follow‐up post‐discharge was 209 days (range, 11‐2184 days), with a total of 143 urine cultures performed in cats post‐discharge. Of these, 16 (11%) were positive in 12/48 (25%) cats. Nine different bacteria were identified; Enterococcus spp. (n = 8) predominated as monomicrobic or mixed infections. In 14/16 instances of positive urine cultures, affected cats had lower urinary tract signs, signs of pyelonephritis or both. Cats that received antibiotics postoperatively were significantly less likely to have a positive urine culture compared to those that did not (odds ratio, 0.2, 95% confidence interval, 0.05, 0.8, P = 0.02). Chronic kidney disease, renal implant type and postoperative urinary catheterization were not associated with positive urine cultures. Conclusions and Clinical Relevance Postoperatively, occurrence of positive urine cultures was similar to previous reports. Subclinical bacteriuria was less common than UTI. Postoperative urinary catheterization has been speculated to increase risk of bacteriuria, but this was not the case in this cohort.

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.

Background Lower urinary tract transitional cell carcinoma (TCC) is an important but rarely described disease of cats. Objectives To report the clinical characteristics, treatments, and outcomes in a cohort of cats with lower urinary tract TCC and to test identified variables for prognostic relevance. Animals One‐hundred eighteen client‐owned cats with lower urinary tract carcinoma. Methods Medical records were retrospectively reviewed to obtain information regarding clinical characteristics, treatments, and outcomes. Recorded variables were analyzed statistically. Results Median age of affected cats was 15 years (range, 5.0‐20.8 years) and median duration of clinical signs was 30 days (range, 0‐730 days). The trigone was the most common tumor location (32/118; 27.1%) as assessed by ultrasound examination, cystoscopy, or both. Treatment was carried out in 73 of 118 (61.9%) cats. Metastatic disease was documented in 25 of 118 (21.2%) cats. Median progression‐free survival and survival time for all cats were 113 days (95% confidence interval [CI], 69‐153) and 155 days (95% CI, 110‐222), respectively. Survival increased significantly (P < .001) when comparing cats across the ordered treatment groups: no treatment, treatment without partial cystectomy, and treatment with partial cystectomy. Partial cystectomy (hazard ratio [HR], 0.31; 95% CI, 0.17‐0.87) and treatment with nonsteroidal anti‐inflammatory drugs (HR, 0.55; 95% CI, 0.33‐0.93) were significantly associated with longer survival times. Conclusions and Clinical Importance The results support treatment using partial cystectomy and NSAIDs in cats with TCC.