Age-related trends in urine specific gravity in apparently healthy cats.

OBJECTIVES: Urine specific gravity (USG) is the most common method for the estimation of urine concentration in cats. Utilization of USG as a screening tool is easily accessible and is of low cost to the client if strategically utilized in settings of higher diagnostic value. There is currently minimal population information regarding how USG changes across ages in cats. METHODS: Data were collected from electronic pet medical records from more than 1000 hospitals and screened for cats with an apparently healthy clinical status and complete diagnostic information. USG was compared with age in multiple analyses to examine the relationship between the variables. RESULTS: In the absence of other indicators of disease, renal concentrating ability begins to diminish, on average, starting at approximately 9 years of age. By age group, cats aged 11-15 years (1.044, 95% confidence interval [CI] 1.043-1.044) had statistically significantly lower mean USGs compared with cats aged less than 1 year (1.049, 95% CI 1.048-1.051; P <0.001), 1-6 years (1.049, 95% CI 1.049-1.050; P <0.001) or 7-10 years (1.049, 95% CI 1.048-1.049; P <0.001). Cats aged ⩾15 years (1.038, 95% CI 1.036-1.040) had statistically significantly lower mean USGs compared with cats aged less than 1 year (P <0.001), 1-6 years (P <0.001), 7-10 years (P <0.001) or 11-15 years (P <0.001). CONCLUSIONS AND RELEVANCE: Renal concentrating ability begins to diminish, on average, starting at approximately 9 years of age and is progressive as cat age increases. This study provides important and new information to help improve screening practices for disorders of concentrating ability in cats.

Assessment of the effect of gabapentin on blood pressure in cats with and without chronic kidney disease.

OBJECTIVES: The aim of the present study was to assess the effect of gabapentin on blood pressure (BP) in cats with and without chronic kidney disease (CKD). METHODS: A randomized, blinded, placebo-controlled crossover study was performed. A total of 29 cats were included: 13 cats with stable CKD (IRIS stage 2-4) and 16 apparently healthy cats (serum creatinine <1.6 mg/dl and urine specific gravity >1.035). The cats were evaluated twice, approximately 1 week apart, and BP (Doppler sphygmomanometry) was obtained 3 h after cats received either a single dose of gabapentin 10mg/kg PO or placebo. For each cat, BP readings were obtained at each visit using the same Doppler and sphygmomanometer unit, and the same cat holder and Doppler operator, in the same location. RESULTS: After administration of a single dose of gabapentin (10 mg/kg PO), BP was significantly lower (median 122 mmHg, range 82-170) than after administration of the placebo (median 150 mmHg, range 102-191; P = 0.001). In the CKD subgroup, BP was significantly lower after administration of gabapentin (median 129 mmHg, range 96-170) than after administration of the placebo (median 155 mmHg, range 102-191; P = 0.008). In the healthy cat subgroup, BP was significantly lower after administration of gabapentin (median 121 mmHg, range 82-139) than after administration of the placebo (median 137 mmHg, range 102-177; P = 0.002). The median change in BP was -12 mmHg (range -95 to 10) for healthy cats and -12 mmHg (range -43 to 21) for cats with CKD (no significant difference between subgroups). CONCLUSIONS AND RELEVANCE: Gabapentin may decrease arterial BP in cats with and without CKD and these findings should be taken into account when gabapentin is administered to patients in which measurement of BP is needed.

Frequency of histologic lesions in the kidneys of cats without kidney disease.

OBJECTIVES: In humans, renal aging is associated with an increased frequency of glomerulosclerosis, interstitial fibrosis, inflammation and tubular atrophy. The purpose of this study was to describe the frequency of renal histopathologic lesions in cats without kidney disease. METHODS: A cross-sectional study of archival kidney tissue from 74 cats without kidney disease (serum creatinine <1.6 mg/dl; urine specific gravity >1.035) was carried out: 0-4 years (young, n = 18); 5-9 years (mature, n = 16); 10-14 years (senior, n = 34), 15+ years (geriatric, n = 6). Glomerulosclerosis, tubular atrophy, interstitial inflammation and fibrosis, and the presence or absence of lipid in the interstitium and tubules were scored by a pathologist masked to clinical data. Statistical analyses were performed as appropriate. RESULTS: Geriatric cats had significantly more glomerulosclerosis than mature (P = 0.01) and young cats (P = 0.004). Senior cats had significantly more glomerulosclerosis than young cats (P = 0.006). Glomerulosclerosis was weakly positively correlated with age (r = 0.48; P <0.0001). Geriatric cats had significantly more tubular atrophy than mature (P = 0.02) and young cats (P <0.0001). Senior cats had significantly more tubular atrophy than young cats (P <0.0001). Geriatric cats had significantly more inflammation than senior cats (P = 0.02), mature cats (P = 0.01) and young cats (P <0.0001). Senior cats had significantly more inflammation than young cats (P = 0.004). Geriatric and senior cats had significantly more fibrosis than young cats (P = 0.01 and P = 0.04, respectively). Frequency of tubular lipid increased with age (young: 28%; mature: 56%; senior: 79%; geriatric: 100%) as did the frequency of interstitial lipid (young: 22%, mature: 56%, senior: 85%, geriatric: 100%). CONCLUSIONS AND RELEVANCE: Evidence of renal aging exists in cats. These changes imply that the aging kidney may be more susceptible to injury and impaired healing.

Effect of repeated administration of a parenteral feline herpesvirus-1, calicivirus, and panleukopenia virus vaccine on select clinicopathologic, immunological, renal histologic, and immunohistochemical parameters in healthy adult cats.

OBJECTIVE: To assess whether hyperinoculation of cats with a feline herpesvirus-1, calicivirus, and panleukopenia virus (FVRCP) vaccine could be used as a model to study interstitial nephritis and to assess humoral and cell-mediated immune responses toward vaccinal α-enolase. ANIMALS: 6 healthy young adult purpose-bred research cats. PROCEDURES: Baseline renal cortical biopsies, whole blood, serum, and urine were collected prior to administration of a commercial FVRCP parenteral vaccine. Vaccine hyperinoculation was defined as a total of 8 vaccinations given at 2-week intervals over a 14-week period. Blood samples were collected immediately prior to each vaccination, and a second renal biopsy was performed 2 weeks after hyperinoculation (week 16). Renal histopathology, renal α-enolase immunohistochemistry, and assays to detect humoral and cell-mediated immune reactions against Crandell-Rees feline kidney (CRFK) cell lysates and α-enolase were performed. An α-enolase immunoreactivity score for renal tubules and glomeruli based on signal intensity was determined by a blinded pathologist. RESULTS: Hyperinoculation with the vaccine was not associated with clinicopathologic evidence of renal dysfunction, and interstitial nephritis was not recognized by light microscopy in the time studied. The mean serum absorbance values for antibodies against CRFK antigen and α-enolase were significantly (P < 0.001) higher at weeks 4, 8, and 16 versus week 0. Renal tubular and glomerular α-enolase immunoreactivity scores were higher at week 16 compared to baseline. CLINICAL RELEVANCE: Findings suggested that systemic immunological reactions occurred and renal tissues were affected by vaccine hyperinoculation; however, short-term FVRCP vaccine hyperinoculation cannot be used to study interstitial nephritis in cats.

Serum concentrations of gabapentin in cats with chronic kidney disease.

OBJECTIVES: The purpose of this study was to assess serum concentrations of gabapentin in cats with chronic kidney disease (CKD) vs clinically healthy cats. METHODS: Five healthy cats were enrolled in a pharmacokinetic study. A single 20 mg/kg dose of gabapentin was administered orally and blood was obtained at 0, 0.25, 0.5, 1, 1.5, 2, 3, 4, 8, 12, 24 and 36 h via a jugular catheter. Serum gabapentin concentrations were measured using liquid chromatography coupled to tandem mass spectrometry. Non-compartmental pharmacokinetic analysis was performed. The same five healthy cats plus 25 cats with stable International Renal Interest Society stage 2 (n = 14) and 3 (n = 11) CKD were enrolled in a limited sampling study. Cats in both groups received a single 10 mg/kg dose of gabapentin, and serum gabapentin concentrations and compliance scores were obtained 3 and 8 h post-administration. RESULTS: Cats with CKD had significantly higher dose-normalized serum gabapentin concentrations than normal cats at 3 h (P = 0.0012 CKD vs normal 10 mg/kg; P = 0.008 CKD vs normal 20 mg/kg) and 8 h (P <0.0001 CKD vs normal 10 mg/kg; P <0.0001 CKD vs normal 20 mg/kg). Both 3 and 8 h dose-normalized serum gabapentin concentrations were significantly correlated with serum creatinine (3 h: P = 0.03, r = 0.39; 8 h: P = 0.001, r = 0.57) and symmetric dimethylarginine (3 h: P = 0.03, r = 0.41; 8 h: P = 0.007, r = 0.48). There was a significant correlation between 3 h serum gabapentin concentrations and compliance scores (P = 0.0002, r = 0.68). CONCLUSIONS AND RELEVANCE: Cats with CKD that received 10 mg/kg of gabapentin had significantly higher dose-normalized serum concentrations than normal cats that received 20 mg/kg, supporting the need to dose-reduce in this patient population.

Survey of defecation habits in apparently healthy and chronic kidney disease cats.

OBJECTIVES: Changes in bowel movements (BMs) are an important clinical sign in many diseases, including chronic kidney disease (CKD), and the purpose of this study was to collect information on BMs and fecal scores in both apparently healthy and CKD cats. A secondary aim was to assess owner awareness of BM frequency. METHODS: Owners were asked to complete an initial online questionnaire about their cat's health and litter box habits (including predicted BM frequency and fecal scores) and were then asked to clean the box daily for 7 days and report results (observed frequency of BMs and fecal scores) daily. Differences in BM frequency and fecal scores between apparently normal and CKD cats were compared using the Mann-Whitney test, and predicted vs observed data were compared using the Wilcoxon signed rank test. Difference in percentage of cats defecating more or less than once daily were assessed with Fisher's exact test. RESULTS: Survey data from 124 owners of apparently healthy cats and 43 owners of CKD cats who submitted two or more days of daily observations (in addition to the initial questionnaire) were analyzed. Eighty-five percent of apparently healthy cats were observed to defecate one or more times per day and 15% defecated less than once per day. Fifty-eight percent of CKD cats defecated one or more times per day and 42% defecated less than once per day. A significantly higher percentage of CKD cats defecated less than once per day in comparison with apparently healthy cats (P <0.0001). Observed BM frequency was significantly less in CKD cats compared with healthy cats (P = 0.02). Observed fecal scores were not significantly different between healthy and CKD cats. CONCLUSIONS AND RELEVANCE: The observed BM frequency of cats with CKD was less than apparently healthy cats and represents a clinically important variation from normal.

Short-term efficacy of epidural pain management in dogs undergoing cystoscopy.

BACKGROUND: The effects of epidural anesthesia in dogs undergoing cystoscopy are unknown. OBJECTIVE: To investigate the effect of epidural analgesia on postcystoscopy pain in dogs. ANIMALS: Twenty-six dogs undergoing routine cystoscopy for lower urinary tract disease. METHODS: Prospective, randomized, blinded observational study. Dogs were assigned either to a treatment group that received epidural anesthesia (preservative free morphine sulfate, 0.09 mg/kg; 1% ropivacaine, 0.2 mg/kg; total volume delivered, 1 mL/4.5 kg of body weight to a maximum of 10 mL; n = 9) or to a nonepidural control group (n = 13). Vital signs were monitored for 24 hours, and sedation and pain scores, behavioral assessments, and presence or absence of complications was evaluated for 5 days postprocedure. RESULTS: All dogs tolerated the epidural without complications. Four dogs were removed from the study because of status unblinding, lack of patient cooperation, or incomplete follow-up. No significant differences were noted in postprocedural pain scores in dogs that received epidural analgesia. Significant differences in postprocedural pain scores were noted in the nonepidural control group. No significant differences were noted in vital signs, behavioral assessments, or the proportion of dogs with a 50% increase in pain scores between the epidural and nonepidural groups. CONCLUSIONS AND CLINICAL IMPORTANCE: Epidural anesthesia was well-tolerated. Dogs not receiving the epidural had poor postprocedural pain control. A consistent benefit for the epidural vs nonepidural group could not be identified. Additional studies are required to better assess the impact and efficacy of epidural anesthesia for cystoscopic procedures.

Evaluation of platelet function in cats with and without kidney disease: a pilot study.

OBJECTIVES: The aims of this study were to determine if stable chronic kidney disease (CKD) cats and uremic crisis cats have altered platelet function, and to determine the prevalence of positive fecal occult blood in CKD cats. METHODS: Platelet function in normal cats, clinically stable International Renal Interest Society (IRIS) stage 2-4 CKD cats and CKD cats experiencing a uremic crisis were evaluated using impedance aggregometry. Area under the curve (AUC) at 6 mins was calculated for saline, adenosine diphosphate (AUCADP) and arachidonic acid (AUCASPI). The AUC in addition to hematocrit, platelet count and mean platelet volume (MPV) were compared between groups using the Kruskal-Wallis test followed by Dunn's post-hoc analysis. Guaiac fecal occult blood tests were performed on fecal samples and results were compared between groups using a χ2 for trend test. RESULTS: AUCADP (P = 0.04) and AUCASPI (P = 0.05) were significantly higher in uremic crisis cats compared with normal cats at 6 mins. Hematocrit was significantly higher in normal cats when compared with IRIS stage 3 and 4 (P = 0.002) and uremic crisis (P = 0.0008) cats, with no difference among groups for platelet count or MPV. The proportion of cats with positive fecal occult blood samples was significantly different between groups (P = 0.0017); 50% uremic crisis cats, 33% IRIS stage 3 and 4 cats, and 10% IRIS stage 2 cats were positive, while no normal cats were positive. The proportion of cats with platelet clumping was significantly different between groups (P = 0.03). CONCLUSIONS AND RELEVANCE: Platelet hyper-reactivity may be occurring in CKD cats experiencing a uremic crisis. The etiology of positive fecal occult blood samples in CKD cats is unclear and did not appear to be related to decreased platelet function as measured in this study and requires further investigation.

Clinicopathologic and pathologic characteristics of feline proteinuric kidney disease.

OBJECTIVES: The aim of this study was to describe the causes, clinicopathologic features and outcomes of feline protein-losing nephropathy (proteinuria secondary to glomerular disease [PLN]). METHODS: Kidney biopsy/necropsy samples from proteinuric cats submitted to the International Veterinary Renal Pathology Service were retrospectively reviewed. Diagnoses based on histopathology were categorized by primary disease compartment. Clinicopathologic variables at diagnosis, development of hypoalbuminemia, anemia, hypertension, azotemia and effusion/edema, and survival were compared between cats with immune-complex glomerulonephritis (ICGN) and other causes of PLN. RESULTS: Fifty-eight percent (n = 31/53) of proteinuric cats had ICGN and 74% (n = 31/42) of cats with PLN had ICGN. Cats with glomerular diseases other than ICGN had a higher median urine protein:creatinine ratio than ICGN cats (14.5 vs 6.5; P <0.001). Onset of PLN occurred at a young age; median age at diagnosis was 3.5 years in ICGN cats vs 1.3 years in cats with other glomerular diseases (P = 0.026). Development of complications such as hypoalbuminemia, anemia, hypertension, azotemia and effusion/edema were common, regardless of the cause of PLN, and were not different between ICGN and cats with other glomerular diseases. Male cats were over-represented in the ICGN group (P = 0.003). Median survival time (MST) for all cats with PLN was 94 days (range 3-1848 days). Survival was not different between cats with ICGN and cats with other glomerular diseases. MST in ICGN cats that developed effusion was shorter (94 days) than cats that did not (700 days; P = 0.035). MST in IGCN cats that received immunosuppressive medications was longer (244 days) than cats that did not (17 days, P = 0.039). CONCLUSIONS AND RELEVANCE: Taken together, these data suggest that clinical suspicion for glomerular proteinuria should increase in young, male cats with higher degrees of proteinuria, and immune-mediated disease is common. Further studies are needed to determine the effect of immunosuppression on morbidity and mortality in cats with ICGN.

Pilot study of side effects and serum and urine concentrations of amoxicillin-clavulanic acid in azotemic and non-azotemic cats.

OBJECTIVES: The aims of this study were to determine the side effect frequency and serum and urine drug concentrations of amoxicillin-clavulanic acid in cats with and without azotemic chronic kidney disease (azCKD). METHODS: Owners whose cats had been prescribed amoxicillin-clavulanic acid completed a survey regarding the occurrence and type of side effects, and whether treatment was altered as a result. Cats were defined as azCKD (serum creatinine concentration >2.0 mg/dl, urine specific gravity [USG] <1.035 with a clinical diagnosis of chronic kidney disease) and without azCKD (serum creatinine concentration <2.0 mg/dl). Data were assessed with Fisher's exact test. Serum and urine samples were obtained from client-owned cats with azCKD (n = 6) and without azCKD (n = 6, serum creatinine concentration <1.8 mg/dl, USG >1.035) that were receiving amoxicillin-clavulanic acid. Amoxicillin and clavulanic acid were measured with liquid chromatography coupled to tandem mass spectrometry and compared between groups with a Mann-Whitney test. Correlation between serum creatinine and drug concentrations in urine and serum was determined using Spearman's rank test. RESULTS: Sixty-one surveys were returned (11 azCKD cats and 50 without azCKD cats). No significant difference in the presence of side effects or type of side effects was seen between groups; however, significantly more azCKD cats had more than one side effect (P = 0.02). More owners of azCKD cats reported that an alteration in treatment plan was necessitated by side effects (55% vs 12%; P = 0.008). Urine amoxicillin was significantly lower in cats with azCKD (P = 0.01) and serum amoxicillin trended toward significance (P = 0.07). Serum amoxicillin concentration was positively correlated with serum creatinine (P = 0.02; r = 0.62) and urine amoxicillin concentration was negatively correlated with serum creatinine (P = 0.01; r = -0.65). CONCLUSIONS AND RELEVANCE: The data suggest that cats with azCKD have altered pharmacokinetics of amoxicillin, which may contribute to an increased incidence of multiple side effects.

Intra- and inter-rater reliability in the cross-sectional area of feline lumbar epaxial musculature evaluated via abdominal CT scan.

OBJECTIVES: The aim of this study was to evaluate the intra- and inter-rater reliability of epaxial muscle cross-sectional area measurement on feline CT images and to determine the relationship between normalized epaxial muscle area (EMA) and subjective muscle condition score (MCS). METHODS: Feline transverse CT images including the junction of the 13th thoracic vertebrae/13th rib head were retrospectively reviewed. Right and left epaxial muscle circumference and vertebral body height were measured and an average normalized EMA (ratio of epaxial area:vertebral height) was calculated for each image. Measurements were performed by three individuals blinded to the clinical data and were repeated 1 month later. Intra- and inter-rater reliability of EMA was assessed with concordance correlation coefficient (CCC), and Bland-Altman analysis was performed to assess bias and limits of agreement (LoA) between and within observers at different time points. In cats for which MCS data were available, EMA was compared between differing MCSs via the Kruskal-Wallis test, with Bonferroni-corrected Wilcoxon rank-sum post-hoc analysis. RESULTS: In total, 101 CT scans met the inclusion criteria for reliability analysis, 29 of which had muscle condition information available for analysis. Intra-rater EMA CCC ranged from 0.84 to 0.99 with minimal bias (range -0.16 to 0.08) and narrow LoA. Inter-rater EMA CCC ranged from 0.87 to 0.94, bias was larger (range -0.46 to 0.66) and LoA were wider when assessed between observers. Median EMA was significantly lower in cats with severe muscle atrophy (2.76, range 1.28-3.96) than in all other MCS groups (P <0.0001 for all comparisons). CONCLUSIONS AND RELEVANCE: Measurement of EMA on CT showed strong intra-rater reliability, and median EMA measurements were significantly lower in cats with severe muscle wasting, as assessed on physical examination. Further studies correlating EMA to lean muscle mass in cats are needed to determine whether this method may be useful to quantify muscle mass in patients undergoing a CT scan.

Retrospective study of the efficacy of oral potassium supplementation in cats with kidney disease.

OBJECTIVES: The aim of this study was to assess the effect of three oral potassium supplements (potassium gluconate tablets [PGT], potassium gluconate granules [PGG] and potassium citrate granules [PCG]) on hypokalemia and serum bicarbonate in cats with chronic kidney disease (CKD). METHODS: Medical records (2006-2016) were retrospectively searched for cats that had been prescribed an oral potassium supplement for management of their CKD-associated hypokalemia. For inclusion, laboratory work had to be available at the time of hypokalemia diagnosis, and at recheck within 1-6 weeks. Treatment response was defined in three ways: any increase in potassium, an increase in potassium to within the normal reference interval, and an increase to >4 mEq/l. RESULTS: Thirty-seven cats met inclusion criteria (16 PGT, 11 PGG, 10 PCG). Dosing ranged from 0.21 to 1.6 mEq/kg/day for PGT, from 0.25 to 1.48 mEq/kg/day for PGG and from 0.04 to 1.34 mEq/kg/day for PCG. After supplementation, 36/37 cats had an increase in potassium, 34/37 increased to within the reference interval and 24/37 had an increase in potassium to >4 mEq/l. There was a statistically significant difference in serum potassium post-supplementation for all three treatments: PGT (P = 0.0001), PGG (P = 0.001) and PCG (P = 0.002). There was a positive correlation between PGT dose and change in potassium concentration (P = 0.04), but there was no significant correlation for PGG or PCG. In cats that had data available, serum bicarbonate increased >2 mEq/l in 1/6 PGT, 1/6 PGG and 3/4 PCG cats. CONCLUSIONS AND RELEVANCE: All three potassium supplements were effective in treating hypokalemia secondary to CKD in the majority of cats despite variable dosing. Data were limited to assess the alkalinizing effect and prospective studies are needed.

Assessment of compounded transdermal mirtazapine as an appetite stimulant in cats with chronic kidney disease.

OBJECTIVES: The aim of this study was to assess the appetite stimulation properties of compounded transdermal mirtazapine (CTM) in cats with chronic kidney disease (CKD). METHODS: Two sequential double-blind placebo-controlled crossover prospective studies were performed in client-owned cats with stable stage 2 or 3 CKD and a history of decreased appetite. In the first study nine CKD cats were randomized to receive 3.75 mg/0.1 ml CTM gel or placebo on the inner pinna every other day for 3 weeks, then, after a 4 day washout period, the cats were crossed over to the alternate 3 week treatment. In a second study, 10 CKD cats were randomized to receive 1.88 mg/0.1 ml CTM or placebo on the same schedule. Physical examination and serum biochemistry were performed before and after each treatment period, and owners kept daily logs of appetite, activity and eating behaviors. Mirtazapine concentrations in CTM gels and steady-state mirtazapine serum concentrations were measured using liquid chromatography/tandem mass spectrometry. RESULTS: Administration of both 3.75 mg and 1.88 mg CTM resulted in a statistically significant increase in weight (P = 0.002 for both), increase in appetite (P = 0.01 and P = 0.005, respectively), and increase in rate of food consumption (P = 0.03 and P = 0.008, respectively). No significant difference in activity or vocalization was seen at either dose; however, individual cats experienced excessive meowing. Median weight increase for the 3.75 mg arm was 0.22 kg (range 0.04-0.44 kg), while median weight increase for the 1.88 mg arm was 0.26 kg (range -0.25 to 0.5 kg). Improvement in body condition score was seen in 5/9 cats in the 3.75 mg arm (P = 0.04) and 6/10 cats in the 1.88 mg arm (P = 0.004). CONCLUSIONS AND RELEVANCE: CTM increased appetite and resulted in weight gain in CKD cats despite significant inconsistencies in compounding, and may benefit cats in countries where an approved product is not available.

Clinicopathologic characteristics, pathology, and prognosis of 77 dogs with focal segmental glomerulosclerosis.

BACKGROUND: Focal segmental glomerulosclerosis (FSGS) is a common cause of nonimmune complex glomerulopathy and the prognosis and clinicopathologic findings associated with this condition have not been described in dogs. OBJECTIVE: To characterize the presentation and identify clinical factors associated with the survival of dogs with FSGS. ANIMALS: Seventy-seven dogs diagnosed with FSGS based on evaluation of renal biopsy samples submitted to the International Veterinary Renal Pathology Service. METHODS: Retrospective review of medical records of dogs biopsied for evaluation of proteinuria between January 2015 and May 2017. RESULTS: The incidence of FSGS among all dogs biopsied for proteinuria was 26%. Significantly more females (48; 62.3%) than males (29; 37.7%) were affected (P = .04). At the time of biopsy, median serum creatinine concentration (SCr) was 1.2 mg/dL (range, 0.3-8.7), median serum albumin concentration (Alb) was 2.8 g/dL (range, 1.1-4.6), median systolic blood pressure was 153.5 mm Hg (range, 95-260), and median urine protein : creatinine ratio was 5.9 (range, 1.4-22). Median survival time after biopsy was 258 days (range, 26-1003) for dogs that died from all causes (n = 32). Factors that were associated with a shorter survival time included SCr ≥ 2.1 mg/dL (P < .01) and Alb < 2 g/dL (P < .01). CONCLUSIONS AND CLINICAL IMPORTANCE: Most dogs with FSGS were female, and although commonly hypertensive, azotemia, severe hypoalbuminemia and ascites or edema were observed infrequently. Variables significantly associated with survival time were SCr and Alb.

Stem Cell Therapy.

Stem cell therapy has tremendous potential for clinical application in the treatment of a variety of diseases in veterinary medicine. Based on the known desirable immunomodulatory properties of mesenchymal stem cells, this therapy has potential for treatment of a variety of renal diseases. This review details our current understanding of stem cell biology and proposed mechanism of action as applicable to renal disease. Studies performed in chronic kidney disease clinical trials and models of acute kidney injury are summarized with the goal of providing an overview of the current status of this treatment modality and its potential for the future.

Mesenchymal stem cell therapy in cats: Current knowledge and future potential.

Practical relevance: Stem cell therapy is an innovative field of scientific investigation with tremendous potential for clinical application in veterinary medicine. Based on the known desirable immunomodulatory properties of mesenchymal stem cells, this therapy holds promise for the treatment of a variety of inflammatory diseases in cats. AIMS: This review details our current understanding of feline stem cell biology and proposed mechanism of action. Studies performed in feline clinical trials for diseases including gingivostomatitis, chronic enteropathy, asthma and kidney disease are summarized, with the goal of providing an overview of the current status of this treatment modality and its potential for the future.

Survey of owner subcutaneous fluid practices in cats with chronic kidney disease.

Objectives The purpose of this study was to survey owners regarding their practices and experiences with the administration of subcutaneous (SC) fluids at home to cats with chronic kidney disease (CKD) to gain insight that might help more owners be successful with the procedure. Methods A web-based survey was advertised online. Owners of 468 cats with CKD participated, 399 of whom administered SC fluids. Results Fifty-nine percent of the cats were domestic shorthairs, with >85% of the cats being 10 years of age or older. IRIS stage 3 was most commonly represented (37%). Ninety-five percent of owners said they discussed giving fluids with their veterinarian, with only 42% of those discussions involving additional educational resources. A large majority of owners (85%) said it was either an easy, somewhat easy/no stress or okay experience for them, and a large majority (89%) reported that the experience was easy/no stress, somewhat easy or okay experience for their cats. To increase tolerance, 57% said they gave a treat to their cat afterwards, and 60% said they warmed the fluids. Sixty-one percent reported using a 20 G or larger needle, with 49% saying size of needle affected tolerance. Seventy-four percent also felt that the length of time it took to administer fluids affected tolerance. One-hundred milliliters was the most commonly given fluid amount. Hydration status was monitored by 40% of owners by various methods, with 40% of those saying they skipped or added fluids based on hydration assessment. Conclusions and relevance A majority of owners gave positive feedback about their ability to learn and administer SC fluids to their cat wth CKD. Owners reported several strategies that they felt improved tolerance of fluid administration. Overall, the protocol should be tailored to the preference of the cat for best possible long-term success.

Preliminary pharmacokinetics of intravenous and subcutaneous dolasetron and pharmacodynamics of subcutaneous dolasetron in healthy cats.

Objectives The objectives were to evaluate the pharmacokinetics (PK) of subcutaneous (SC) and intravenous (IV) dolasetron and the pharmacodynamics (PD) of SC dolasetron in healthy cats. Methods Five cats with unremarkable complete blood count, serum biochemistry and urinalyses were utilized. In the PK study, cats received 0.8 mg/kg SC and IV dolasetron in a crossover format. Serum samples were obtained via a jugular catheter at 0, 0.25, 0.5, 1, 2, 4, 8, 12, 24, 36 and 48 h after the administration of dolasetron. Dolasetron and the active metabolite hydrodolasetron were measured using liquid chromatography/tandem mass spectrometry. Non-compartmental PK analysis was performed. In the PD study, SC dolasetron (0.8 mg/kg and 1.0 mg/kg) and saline were administered 30 mins prior to administration of 0.44 mg/kg intramuscular xylazine in a randomized three-way crossover. Number of emetic events, lip licks, time to onset of emesis and visual nausea score were scored by a blinded observer. Results In the PK study, dolasetron was quickly metabolized to the active metabolite hydrodolasetron, limiting assessment of dolasetron PK parameters. Median (range) PK parameters for IV hydrodolasetron were as follows: maximum serum concentration (Cmax) 116 ng/ml (69-316 ng/ml), time to maximum concentration (Tmax) 0.5 h (0.3-0.5 h), half-life 3.3 h (2.9-7.2 h) and area under the curve until the last measurable concentration (AUClast) 323 h/ng/ml (138-454 h/ng/ml). Median (range) PK parameters for SC hydrodolasetron were as follows: Cmax 67.9 ng/ml (60.4-117 ng/ml), Tmax 0.5 h (0.5-1.0 h), half-life 3.8 h (2.9-5.3 h) and AUClast 437 h/ng/ml (221.5-621.8 h/ng/ml). There was no significant difference in exposure to hydrodolasetron between the routes of administration. With regard to PD, when dolasetron was administered prior to xylazine, there was no significant difference in the mean number of emetic events, lip licks, time to onset of emesis or visual nausea score when compared with saline. Conclusions and relevance Administration of 0.8 mg/kg dolasetron does not maintain serum concentrations of active metabolite for 24 h. Administration of dolasetron at 0.8 mg/kg and 1 mg/kg did not prevent xylazine-induced vomiting. Additional feline dose studies are needed to determine if a higher dose is efficacious.

Assessment of absorption of transdermal ondansetron in normal research cats.

Objectives The objective of this study was to assess the absorption of transdermal ondansetron in healthy cats. Methods Five research cats with unremarkable complete blood count, biochemistry and urinalysis were used for both single- and multiple-dose application studies. For single-dose application, 4 mg ondansetron in 0.1 ml Lipoderm gel was applied once to the internal ear pinna. Blood samples were collected via jugular catheter over a 48 h period following administration (0, 15 mins, 30 mins, 1 h, 2 h, 4 h, 8 h, 12 h, 24 h and 48 h). For multiple-dose application, 4 mg ondansetron in 0.1 ml Lipoderm gel was applied for five consecutive days before blood samples were obtained in the same manner. Serum was separated and frozen prior to analysis. Ondansetron was measured via liquid chromatography coupled to tandem mass spectrometry. Results Analysis revealed no clinically relevant drug levels in serum after either single- or multiple-dose administration of 4 mg transdermal ondansetron. Conclusions and relevance Transdermal application of 4 mg ondansetron does not result in clinically relevant serum concentrations of drug. Despite characteristics of the drug that imply suitability for transdermal application, this does not appear to be an acceptable method of drug delivery for this medication at this dose. This study highlights the importance of assessing the suitability of each medication for transdermal administration.

Renal pelvic and ureteral ultrasonographic characteristics of cats with chronic kidney disease in comparison with normal cats, and cats with pyelonephritis or ureteral obstruction.

Objectives The objective was to describe ultrasonographic characteristics of cats with stable chronic kidney disease (CKD) and determine if these were significantly different from cats with pyelonephritis (Pyelo) and ureteral obstruction (UO), to aid in clinical assessment during uremic crisis. Methods Sixty-six cats with stable CKD were prospectively enrolled, as well as normal control cats (n = 10), cats with a clinical diagnosis of Pyelo (n = 13) and cats with UO confirmed by surgical resolution (n = 11). Renal ultrasound was performed and routine still images and cine loops were obtained. Analysis included degree of pelvic dilation, and presence and degree of ureteral dilation. Measurements were compared between groups using non-parametric one-way ANOVA with Dunn's post-hoc analysis. Results In total, 66.6% of CKD cats had measurable renal pelvic dilation compared with 30.0% of normal cats, 84.6% of Pyelo cats and 100% of UO cats. There was no statistically significant difference in renal pelvic widths between CKD cats and normal cats, or CKD cats and Pyelo cats. On almost all measurement categories, UO cats had significantly greater renal pelvic widths compared with CKD cats and normal cats ( P <0.05) but not Pyelo cats. Six percent of stable CKD cats had measurable proximal ureteral dilation on one or both sides vs 46.2% of Pyelo cats and 81.8% of UO cats. There was no statistically significant difference in proximal ureteral width between normal and CKD cats, or between Pyelo and UO cats. There was a statistically significant difference in proximal ureteral width between CKD and Pyelo cats, CKD and UO cats, normal and UO cats, and normal and Pyelo cats. Conclusions and relevance No significant difference in renal pelvic widths between CKD cats and Pyelo cats was seen. These data suggest CKD cats should have a baseline ultrasonography performed so that abnormalities documented during a uremic crisis can be better interpreted.