Total protein measurement in canine cerebrospinal fluid: agreement between a turbidimetric assay and 2 dye-binding methods and determination of reference intervals using an indirect a posteriori method.

BACKGROUND: In veterinary clinical laboratories, qualitative tests for total protein measurement in canine cerebrospinal fluid (CSF) have been replaced by quantitative methods, which can be divided into dye-binding assays and turbidimetric methods. There is a lack of validation data and reference intervals (RIs) for these assays. OBJECTIVES: The aim of the present study was to assess agreement between the turbidimetric benzethonium chloride method and 2 dye-binding methods (Pyrogallol Red-Molybdate method [PRM], Coomassie Brilliant Blue [CBB] technique) for measurement of total protein concentration in canine CSF. Furthermore, RIs were determined for all 3 methods using an indirect a posteriori method. METHODS: For assay comparison, a total of 118 canine CSF specimens were analyzed. For RIs calculation, clinical records of 401 canine patients with normal CSF analysis were studied and classified according to their final diagnosis in pathologic and nonpathologic values. RESULTS: The turbidimetric assay showed excellent agreement with the PRM assay (mean bias 0.003 g/L [-0.26-0.27]). The CBB method generally showed higher total protein values than the turbidimetric assay and the PRM assay (mean bias -0.14 g/L for turbidimetric and PRM assay). From 90 of 401 canine patients, nonparametric reference intervals (2.5%, 97.5% quantile) were calculated (turbidimetric assay and PRM method: 0.08-0.35 g/L (90% CI: 0.07-0.08/0.33-0.39); CBB method: 0.17-0.55 g/L (90% CI: 0.16-0.18/0.52-0.61). Total protein concentration in canine CSF specimens remained stable for up to 6 months of storage at -80°C. CONCLUSIONS: Due to variations among methods, RIs for total protein concentration in canine CSF have to be calculated for each method. The a posteriori method of RIs calculation described here should encourage other veterinary laboratories to establish RIs that are laboratory-specific.

[The significance of elbow dysplasia (ED) for breeding in Bernese Mountain Dogs in Germany]. / Untersuchungen zur züchterischen Bedeutung der Ellbogendysplasie (ED) beim Berner Sennenhund in Deutschland.

Results from the elbow dysplasia screening program in Bernese Mountain Dogs of Germany were analysed in respect to its relevance for genetic evaluation and breeding. In total 2677 gradings were used. The grading was performed radiographically according to the recommendations of the International Elbow Working Group (IEWG). 75.8% of the dogs were free from visible dysplastic signs, 10.8%, 6.8% and 5.5% were classified to be of Grade 1, 2 and 3, respectively. 1.1% were classified as a borderline case between ED-free and Grade 1. A slight reduction of ED could be observed over years. Males had a 3.1 higher rate of dysplasia than females. Treating ED as a numerical trait, coded proportional to the severity of clinical relevant signs, gave a heritability estimation of 0.188 and a maternal effect of 0.07. From different mating combinations it was found, that ED average was higher in the progeny if one mate was affected but there was no increase in the prevalence with increasing grade of ED in the affected mates. About 10% more affected dogs could be observed, if one mate is affected. Heritability for dichotomic coding the trait was found to be 0.20. From these results can be suggested, that the differentiation in various grades of ED to describe the clinical relevance for the specific dog is helpfull, however, from a breeders point of view, dogs with ED should be treated equally for genetic evaluation.