No abstract

ABSTRACT. The serum cystatin C (Cys-C) concentration is a better filtration marker than plasma creatinine (Cre) concentration in humans. In veterinary medicine, a few studies have shown that the serum Cys-C concentration in dogs is also a better marker than the plasma Cre concentration. The purpose of this study is to evaluate the applicability of measuring the serum Cys-C concentration by an enzymelinked immunosorbent assay (ELISA) as a marker of the glomerular filtration rate in dogs with various renal dysfunctions. The serum Cys-C concentration in dogs with chronic kidney disease (CKD) was significantly higher (1.23  0.21 mg/L) than that in 76 control dogs (0.85  0.15) (P<0.001). The reference range of the serum Cys-C concentrations in samples from the 76 control dogs was 0.55-1.15 mg/l. Serum Cys-C concentration was more strongly correlated with plasma iohexol clearance (r=-0.704, P<0.001) than plasma Cre concentration in dogs (r=-0.598, P<0.001). In a receiver operating characteristics analysis, significant differences between the serum Cys-C and plasma Cre concentrations were found with regard to their AUC (0.949, [SE, 0.019] and 0.849 [SE, 0.029]) and diagnostic sensitivity (90.3% and 73.6%) for detecting decreased PCio (P<0.05). Therefore, the measurement of serum Cys-C concentration by ELISA is more useful for the detection of early CKD than measuring the plasma Cre concentration.KEY WORDS: chronic kidney disease, cystatin C, glomerular filtration rate.

ABSTRACT. Chronic kidney disease is one of the most common disorders in dogs and cats. The plasma urea nitrogen (P-UN) and creatinine (P-Cre) concentrations are not sufficiently sensitive for early diagnosis of renal dysfunction. Although urine and plasma clearance methods allow earlier detection of reductions in the GFR, it is difficult to estimate a mildly reduced GFR from the values obtained by these methods, as they are also affected by physiological factors, such as body weight (BW) and age. The present study is a retrospective survey designed to assess the factors that affect markers of kidney function and to revaluate the clinical utility of the markers, including P-UN, P-Cre and GFR determined by plasma iohexol clearance (PCio) in dogs and cats. The P-UN, P-Cre and PCio values in dogs and the P-Cre and PCio values in cats were significantly correlated with BW (P<0.001). PCio in smaller dogs (15.0 kg) was significantly and inversely correlated with age. In smaller dogs, increase of P-UN alone might warrant a suspicion of a decreased GFR, but in contrast, P-Cre may be inefficient for detecting renal dysfunction or determining the severity of CKD compared with that in larger dogs ( 15.1 kg). P-Cre in larger dogs correlated better with PCio than in smaller dogs, suggesting that P-Cre in larger dogs was a more sensitive marker of reduced GFR.KEY WORDS: body weight, plasma creatinine, plasma iohexol clearance, plasma urea nitrogen.J. Vet. Med. Sci. 72(9): 1129-1136, 2010 Chronic kidney disease (CKD) is one of the most common disorders and is a common cause of death in dogs and cats. The prevalence of renal diseases has been reported to range from 0.5 to 7% in dogs and from 1.6 to 20% in cats [29,43]. Although CKD occurs in dogs and cats of all ages, the mortality of CKD commonly increases with age. In human and veterinary medicine, CKD is diagnosed by detecting chronic decreases in the glomerular filtration rate (GFR) or the presence of chronic renal damage [4,36]. GFR can be evaluated indirectly from the concentrations of plasma and urine markers, which are dependent on the amount eliminated by the kidneys. The plasma urea nitrogen (P-UN) and creatinine (P-Cre) concentrations are widely used as endogenous markers to evaluate renal function in dogs and cats because they can be easily, rapidly and cheaply measured. GFR is measured directly by urine or plasma clearance methods using inulin, creatinine or iohexol [7,14,15,20,21,33,34]. Although the urinary clearances of inulin and creatinine are considered to be the gold standards for measuring GFR in humans and animals, these methods are impractical in clinical settings because they require insertion of a bladder catheter, which is associated with a risk of developing a urinary tract infection or urethral injury; complete collection of a timed urine sample; and continuous infusion of the marker. The single injection technique can be used to determine plasma clearance from the elimination curve of a marker in plasma after a bolus injection. Plasma clearance ca...

The double-chambered right ventricle (DCRV) is a rare congenital cardiac disease in dogs, and its detailed epidemiological and morphological features are not clearly understood. By investigating the profile, clinical signs, and characteristics of examination findings of eleven dogs with DCRV by means of a retrospective study, we attempted to clarify the epidemiology and morphology of the condition. The study group consisted of nine males and two females. Breeds included Pug (n=3), Miniature Dachshund (n=1), French Bull-dog (n=1), Shiba (n=1), and Retrievers (n=5). The attachment site of the anomalous muscular bundle was continuous with the cardiac apex in nine dogs, and it was attached to the right ventricle free wall in the other two dogs. In dogs with DCRV, at least one of the following conditions was present concurrently: congenital or acquired tricuspid valve regurgitation (TR), ventricular septal defect, and atrial septal defect. Also, the pressure difference between the two chambers increased over time, and progressive right-sided heart failure was observed. In summary, DCRV occurs in small breeds of dog as well as in large breeds of dog and it may be more prevalent in males. The existence of two types of DCRV in dogs was established. Dog with DCRVs will have a high incidence of concurrent cardiac abnormalities. Concurrent TR may be either congenital or acquired. DCRV is a congenital disorder, but the clinical condition progresses as the dog develops.

ABSTRACT. Plasma iohexol clearance (PCio) is a practical method for measuring the glomerular filtration rate (GFR) in clinical settings. However, it is too time-consuming for routine application and requires hospitalization for at least half a day. Therefore, the development of a simpler procedure for plasma clearance is necessary to allow the frequent measurement of GFR in clinical settings. The purpose of the present study was to evaluate a single sampling method for estimation of PCio in dogs and cats with various kidney functions. The PCio determined by the 1-compartment model using 3 samples (PCio 3samples ) was used as a reference for the evaluation of the single sampling method (PCio single ). Plasma iohexol concentration was determined by a cerium arsenite colorimetric method.