Gilad Segev

A Novel Clinical Scoring System for Outcome Prediction in Dogs with Acute Kidney Injury Managed by Hemodialysis

BACKGROUND No reliable tool to predict outcome of acute kidney injury (AKI) exists. HYPOTHESIS A statistically derived scoring system can accurately predict outcome in dogs with AKI managed with hemodialysis. ANIMALS One hundred and eighty-two client-owned dogs with AKI. METHODS Logistic regression analyses were performed initially on clinical variables available on the 1st day of hospitalization for relevance to outcome. Variables with P< or = .1 were considered for further analyses. Continuous variables outside the reference range were divided into quartiles to yield quartile-specific odds ratios (ORs) for survival. Models were developed by incorporating weighting factors assigned to each quartile based on the OR, using either the integer value of the OR (Model A) or the exact OR (Models B or C, when the etiology was known). A predictive score for each model was calculated for each dog by summing all weighting factors. In Model D, actual values for continuous variables were used in a logistic regression model. Receiver-operating curve analyses were performed to assess sensitivities, specificities, and optimal cutoff points for all models. RESULTS Higher scores were associated with decreased probability of survival (P < .001). Models A, B, C, and D correctly classified outcomes in 81, 83, 87, and 76% of cases, respectively, and optimal sensitivities/specificities were 77/85, 81/85, 83/90 and 92/61%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE The models allowed outcome prediction that corresponded with actual outcome in our cohort. However, each model should be validated further in independent cohorts. The models may also be useful to assess AKI severity.

Urethral obstruction in cats: Predisposing factors, clinical, clinicopathological characteristics and prognosis

Feline lower urinary tract diseases in general, and urethral obstruction (UO) in particular, are common clinical conditions in cats. The aims of this study were to identify risk factors for UO, to characterise clinical and clinicopathological signs, outcome and recurrence, as well as risk factors for mortality and recurrence. Eighty-two cats with UO were compared to 82 sex and time matched controls. The mean age of cats with UO was significantly lower compared to controls, while the mean body weight was higher. The proportion of indoors–outdoors cats was significantly lower in the study group compared to the control group, and the proportion of cats consuming only dry food was higher. Overall mortality was 8.5%. Ionised calcium was significantly higher in survivors compared to non-survivors, and the prevalence of hypocalcaemia was lower. Recurrence in 6 months and 2 years were 22% and 24%, respectively. Cats with recurrence had significantly lower urine pH at presentation.

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.

Cardiac Arrhythmias and Serum Cardiac Troponins in Vipera palaestinae Envenomation in Dogs

BACKGROUND Vipera palaestinae is responsible for most poisonous envenomations in people and animals in Israel. Cardiac arrhythmias were reported in a retrospective study of V. palaestinae envenomations in dogs. HYPOTHESIS Cardiac arrhythmias in V. palaestinae-envenomed dogs are associated with myocardial injury reflected by increased serum concentrations of cardiac troponins (cTns). ANIMALS Forty-eight client-owned dogs envenomed by V. palaestinae. METHODS Blood sampling (serum biochemistry and cTns, CBC, and coagulation tests) and electrocardiography were performed periodically up to 72 hours postenvenomation. Cardiac rhythm strips were assessed blindly for the presence and type of arrhythmias. RESULTS Serum cTn-T and cTn-I concentrations were increased in 25% (n = 12) and 65% (n = 31) of the dogs at least once during hospitalization, respectively. Arrhythmias were identified in 29% (n = 14) of the dogs. Dogs with increased cTn-T had a significantly higher occurrence of arrhythmias (58 versus 19%), and higher resting heart rate upon admission and within the following 24 hours. Dogs with increased serum cTn-T concentrations were hospitalized for a significantly (P= .001) longer period compared to those with normal serum cTn-T concentrations. CONCLUSIONS AND CLINICAL RELEVANCE Dogs envenomed by V. palaestinae appear to sustain some degree of myocardial injury, as reflected by increased serum cTn concentrations and by the occurrence of arrhythmias. The latter should alert clinicians to a potentially ongoing cardiac injury. An increase in cTn-T may be of clinical relevance and indicate a cardiac injury in V. palaestinae envenomations in dogs.

Evaluation of Urinary Catheters Coated with Sustained-Release Varnish of Chlorhexidine in Mitigating Biofilm Formation on Urinary Catheters in Dogs

BACKGROUND Biofilm formation occurs commonly on urinary catheters. OBJECTIVES To assess the efficacy of urinary catheters coated with sustained-release varnish of chlorhexidine in decreasing catheter-associated biofilm formation in dogs. ANIMALS Thirty client-owned dogs. METHODS Prospective study. Thirteen dogs were catheterized with urinary catheters coated with sustained-release varnish of chlorhexidine (study group), and 13 dogs were catheterized with an untreated urinary catheter (control group). Presence and intensity of biofilm formation on the urinary catheters were assessed and compared between the groups by evaluating colony-forming units (CFU) of biofilm bacteria, and semiquantitatively, using confocal laser scanning microscopy and electron microscopy. RESULTS None of the dogs experienced adverse effects associated with the presence of the urinary catheters. Median CFU count of biofilm bacteria at all portions of the urinary catheter was significantly (P < .001) lower in the study compared with the control group. The degree of biofilm formation on the urinary catheters, as evaluated by confocal laser scanning microscopy and electron microscopy, was significantly lower in the study compared with the control group. Electron microscopy examination identified crystals on some of the urinary catheters. The proportion of catheters on which crystals were observed was significantly lower on the distal part of the urinary catheter in the study group compared with the control group (16.7% versus 66.7%, respectively; P = .04). CONCLUSIONS AND CLINICAL IMPORTANCE Chlorhexidine sustained-release varnish-coated urinary catheters effectively decrease urinary catheter-associated biofilm formation in dogs.

Peripheral nucleated red blood cells as a prognostic indicator in heatstroke in dogs.

BACKGROUND Heatstroke in dogs is often fatal and is associated with a high prevalence of secondary complications. Peripheral nucleated red blood cells (NRBC) occur in dogs with heatstroke, but their association with complications and the outcome is unclear. HYPOTHESIS Peripheral NRBC are common in dogs with heatstroke and have prognostic significance. ANIMALS Forty client-owned dogs with naturally occurring heatstroke. METHODS Prospective, observational study. Dogs were followed from presentation to discharge or death. Serum biochemistry and coagulation tests were performed at presentation. CBC and evaluation of peripheral blood smears were performed at presentation and every 12 hours. The relative and the absolute NRBC numbers were calculated. RESULTS Presence of NRBC was observed in 36/40 (90%) of the dogs at presentation. Median relative and absolute NRBC were 24 cells/100 leukocytes (range 0-124) and 1.48 x 10(3)/microL (range 0.0-19.6 x 10(3)/microL), respectively. Both were significantly higher in nonsurvivors (22) versus survivors (18) and in dogs with secondary renal failure and DIC versus those without these complications. Receiver operator curve analysis of relative NRBC at presentation as a predictor of death had an area under curve of 0.92. A cut-off point of 18 NRBC/100 leukocytes corresponded to a sensitivity and specificity of 91 and 88% for death. CONCLUSIONS AND CLINICAL IMPORTANCE Relative and absolute numbers of peripheral NRBC are clinically useful, correlate with the secondary complications, and are sensitive and specific markers of death in dogs with heatstroke, although they should never be used as a sole prognostic indicator nor should they replace clinical assessment.

Increased serum leptin and insulin concentrations in canine hypothyroidism

Serum concentrations of leptin and insulin were compared between gender-matched hypothyroid (n=25) and healthy (n=25) client-owned dogs within comparable age and body condition score (BCS) ranges. Fasted blood samples were collected from each dog and analysed for glucose, cholesterol, triglyceride, leptin and insulin concentrations. Leptin and insulin concentrations were significantly higher in the hypothyroid compared to normal dogs (P=0.006 and P=0.001, respectively) following adjustment for potential confounders. A nearly significant (P=0.051) interaction with BCS was found in the association between hypothyroidism and leptin. Leptin concentrations were significantly higher in hypothyroid dogs compared to normal dogs, in separate analyses for BCS 6 (P=0.036) and 7 (P=0.049). There was no significant difference in glucose concentration between the hypothyroid and normal groups (P=0.84) following adjustment for BCS. This study showed that canine hypothyroidism is associated with increased serum leptin and insulin concentrations, neither of which may be attributed to obesity alone.

Unremodeled endochondral bone is a major architectural component of the cortical bone of the rat (Rattus norvegicus).

The laboratory rat is one of the most frequently-used animal models for studying bone biology and skeletal diseases. Here we show that a substantial portion of the cortical bone of mature rats is primary endochondral bone, consisting of a disorganized arrangement of mineralized collagen fibers. We characterize the structure and mechanical properties of the cortical bone of the rat. We show that the cortical bone consists of two architecturally distinct regions. One region, consisting of well-organized circumferential lamellae (CLB), is located in the endosteal and/or the periosteal regions while another, disorganized region, is located in the more central region of the cortex. Unexpectedly, we found that the disorganized region contains many islands of highly mineralized cartilage. Micro tomography showed different structural and compositional properties of the two primary structural elements; the CLB region has lower mineral density, lower porosity, larger but fewer blood vessels and fewer lacunae. However, no difference was found in the average lacunar volume. Additionally the mean indentation modulus of the CLB region was lower than that of the disorganized region. The islands of calcified cartilage were found to be extremely stiff, with an indentation modulus of 33.4 ± 3.5GPa. We conclude that though the cortical bone of rats is in part lamellar, its architecture is markedly different from that of the cortical bone of humans, a fact that must be borne in mind when using the rat as a model animal for studies of human bone biology and disease.

Central diabetes insipidus in five cats: clinical presentation, diagnosis and oral desmopressin therapy

Five cases of central diabetes insipidus (CDI) in domestic shorthair cats are described. All cats were under 3 years of age at the onset of clinical signs, and outdoor or outdoor/indoor cats, in which a prior trauma was either present or possible. The history included polydipsia and polyuria, and physical examination abnormalities included urinary bladder distention and dehydration. All cats had hyposthenuria with a urine specific gravity between 1.003 and 1.006. The diagnosis was confirmed by an observed inability to concentrate urine during a water deprivation test or compatible serum osmolality, followed by an increase in urine concentration after desmopressin administration. All cats in this report were treated successfully with oral desmopressin. The dose (25–50 μg q8–12h) and the response to therapy were variable. Oral desmopressin administration may serve as an effective alternative route for cat owners who find the conjunctival or nasal application of the solution an inconvenient mode of therapy.

Toxic Neutrophils in Cats: Clinical and Clinicopathologic Features, and Disease Prevalence and Outcome—A Retrospective Case Control Study

Toxic neutrophils exhibit a variety of nuclear and cytoplasmic abnormalities in Romanowsky-stained blood smears, and are associated with inflammation and infection. The purpose of the retrospective study reported here was to investigate the association of toxic neutrophils with clinicopathologic characteristics, diseases, and prognosis in cats. Cats with toxic neutrophils (n = 150) were compared with negative-control cats (n = 150). Statistical analyses included Fisher exact, independent t-, nonparametric Mann-Whitney, and chi-squared tests. Cats with toxic neutrophils had significantly (P < .05) higher prevalence of fever, icterus, vomiting, diarrhea, depression, dehydration, weakness, and cachexia, as well as leukocytosis, neutrophilia, left shift, neutropenia, anemia, hypokalemia, and hypocalcemia. The prevalence of shock, sepsis, panleukopenia, peritonitis, pneumonia, and upper respiratory tract diseases was significantly higher among these cats, as were infectious (viral and bacterial) and metabolic disorders. Control cats had a significantly higher prevalence of feline asthma, as well as allergic, idiopathic, and vascular disorders. Hospitalization duration and treatment cost were significantly (P < .001) higher in cats with toxic neutrophils. In 53 and 47% of the cats with toxic neutrophils, the leukocyte and neutrophil counts were normal, respectively, whereas in 43%, both abnormalities and left shift were absent, and toxic neutrophils were the only hematologic evidence of inflammation or infection. In conclusion, toxic neutrophils were found to be associated with certain clinicopathologic abnormalities, and when present, may aid in the diagnosis, as well as the assessment of hospitalization duration and cost. The evaluation of blood smears for toxic neutrophils provided useful clinical information.