Impact of regression modeling on the assessment and harmonization of a point-of-care analyzer and commercial laboratory analyzer for feline plasma biochemistry testing.

Background: Regression describes the relationship of results from two analyzers, and the generated equation can be used to harmonize results. Point-of-care (POC) analyzers cannot be calibrated by the end user, so regression offers an opportunity for calculated harmonization. Harmonization (uniformity) of laboratory results facilitates the use of common reference intervals and medical decision thresholds.

Analytical performance of feline plasma on current Heska and IDEXX point-of-care biochemistry analyzers compared with a commercial laboratory analyzer.

Background: Point-of-care (POC) biochemistry analyzers are widely used in small animal clinical practice but infrequently independently assessed for performance.

Objective: To assess the performance of two current model point-of-care biochemistry analyzers (Heska Element DC and IDEXX Catalyst) compared with a commercial laboratory analyzer (Cobas 8000).

Methods: One hundred twenty-one cats from a feline hospital population were sampled with plasma results from a single lithium heparin tube assessed on all three analyzers.

Analytical quality performance goals for symmetric dimethylarginine in cats.

Background: Symmetric dimethylarginine (SDMA) reflects the glomerular filtration rate (GFR) in people, dogs, and cats. Initial assays used a liquid chromatography-mass spectroscopy (LC) technique. A veterinary immunoassay has been developed for use in commercial laboratories and point-of-care (POC) laboratory equipment.

Current and emerging concepts in biological and analytical variation applied in clinical practice.

A single laboratory result actually represents a range of possible values, and a given laboratory result is impacted not just by the presence or absence of disease, but also by biological variation of the measurand in question and analytical variation of the equipment used to make the measurement. Biological variation refers to variability in measurand concentration or activity around a homeostatic set point. Knowledge of biological and analytical variation can be used to facilitate interpretation of patient clinicopathologic data and is particularly useful for interpreting serial patient data and data at or near reference limits or clinical decision thresholds.

Analytical quality goals-a review.

Analytical quality goals indicate how laboratory tests must perform to be clinically useful for their intended purpose. These goals have historically focused on analytical error assessment for quantitative methods and vary with measurand concentration or activity, and species. Although formalized quality goal models have been developed in human medicine, quality goals in veterinary medicine, to date, have not been formalized; use of human regulatory-based goals, consensus-based goals, or biologic variation-based goals have been reported most often.

Recommendations for designing and conducting veterinary clinical pathology biologic variation studies.

The recent creation of a veterinary clinical pathology biologic variation website has highlighted the need to provide recommendations for future studies of biologic variation in animals in order to help standardize and improve the quality of published information and to facilitate review and selection of publications as standard references. The following recommendations are provided in the format and order commonly found in veterinary publications. A checklist is provided to aid in planning, implementing, and evaluating veterinary studies on biologic variation (Appendix S1).

Commutability and interchangeability of commercial quality control materials with feline plasma for common biochemical analytes.

Background: Species-specific plasma or serum pools are considered the ideal standard material for quality control materials (QCM) instead of commercially available human QCM. However, using plasma or serum pools is limited by volume restrictions, degradation over time, and a narrow range of analyte concentrations. Concentrations of QCM analytes should be consistent or commutable with those from species-specific plasma/serum samples, and the precision from plasma pools should be comparable or interchangeable with commercial human QCM.

Bias in feline plasma biochemistry results between three in-house analysers and a commercial laboratory analyser: results should not be directly compared.

In-house analysers are commonplace in small animal practices but cannot be calibrated by the operator; therefore, any bias in the generated plasma analyte values cannot be corrected. Guidelines such as grading of renal disease and published reference intervals (RIs) in veterinary textbooks assume plasma biochemistry values generated by different analysers are equivalent. This study evaluated the degree of bias, as well as if bias was constant or proportional, for feline plasma biochemical analytes assessed by three in-house biochemistry analysers compared with a commercial laboratory analyser.

Assessments of feline plasma biochemistry reference intervals for three in-house analysers and a commercial laboratory analyser.

For each species, the manufacturers of in-house analysers (and commercial laboratories) provide standard reference intervals (RIs) that do not account for any differences such as geographical population differences and do not overtly state the potential for variation between results obtained from serum or plasma. Additionally, biases have been demonstrated for in-house analysers which result in different RIs for each different type of analyser. The objective of this study was to calculate RIs (with 90% confidence intervals [CIs]) for 13 biochemistry analytes when tested on three commonly used in-house veterinary analysers, as well as a commercial laboratory analyser.

Biological variation and reference change values of feline plasma biochemistry analytes.

This is the first report concerning biological variation and reference change values of feline plasma biochemistry components in the peer-reviewed literature. Biological variation refers to inherent physiological variation of analytes. The ratio of individual biological variation to group biological variation is referred to as an analyte's index of individuality.

A retrospective analysis of the effects of meloxicam on the longevity of aged cats with and without overt chronic kidney disease.

The study sought to examine the effect of long-term meloxicam treatment on the survival of cats with and without naturally-occurring chronic kidney disease at the initiation of therapy. The databases of two feline-only clinics were searched for cats older than 7 years that had been treated continuously with meloxicam for a period of longer than 6 months. Only cats with complete medical records available for review were recruited into the study.

Feline low-grade alimentary lymphoma: how common is it?

Low-grade alimentary lymphoma (LGAL) requires histological assessment of biopsies for diagnosis whereas intermediate- (IGAL) and high-grade (HGAL) alimentary lymphoma (AL) can be diagnosed by cytology of intestinal or mesenteric lymph node aspirates. Assessment of the relative frequency of subtypes of AL using histology alone may be skewed towards an increased frequency of LGAL as cases of IGAL or HGAL diagnosed cytologically may not progress to biopsy. We investigated the relative prevalence of AL subtypes diagnosed by both histopathology and cytology among primary accession cases across Australia during a 5-year period.

Preliminary post-prandial studies of Burmese cats with elevated triglyceride concentrations and/or presumed lipid aqueous.

A proportion of Burmese cats in Australia have an exaggerated post-prandial triglyceride (TG) response after an oral fat tolerance test (OFTT). The aim of this study was to determine (a) whether Burmese cats with presumed lipid aqueous (PLA) had exaggerated post-prandial triglyceridaemia, (b) if Burmese cats with exaggerated post-prandial triglyceridaemia ('affected' cats) had decreased lipoprotein lipase (LPL) activity and (c) whether affected cats were more insulin resistant than normal Burmese cats. Of cats with a history of PLA, 4/5 were shown to be lipid intolerant (4h TG>4.

Assessment of the Accutrend GCT and PTS CardioChek meters to measure blood triglyceride concentrations in cats.

Point-of-care (POC) meters that determine whole blood triglyceride (TG) concentrations are used in human medicine to monitor both fasting and post-prandial TG concentrations. The aim of this study was to evaluate their performance for determining feline TG concentrations. A total of 116 venous blood samples were collected from 55 cats.

Triglyceride response following an oral fat tolerance test in Burmese cats, other pedigree cats and domestic crossbred cats.

Primary lipid disorders causing fasting triglyceridaemia have been documented infrequently in Burmese cats. Due to the known increased risk of diabetes mellitus and sporadic reports of lipid aqueous in this breed, the aim of this study was to determine whether healthy Burmese cats displayed a more pronounced pre- or post-prandial triglyceridaemia compared to other cats. Serum triglyceride (TG) concentrations were determined at baseline and variably at 2, 4 and 6h after ingestion of a high-fat meal (ie, an oral fat tolerance test) in a representative sample of Burmese and non-Burmese cats.

Prevalence of feline immunodeficiency virus infection in domesticated and feral cats in eastern Australia.

Serum samples from 340 pet cats presented to three inner city clinics in Sydney Australia, 68 feral cats from two separate colonies in Sydney, and 329 cattery-confined pedigree and domestic cats in eastern Australia, were collected over a 2-year period and tested for antibodies directed against feline immunodeficiency virus (FIV) using immunomigration (Agen FIV Rapid Immunomigration test) and enzyme-linked immunosorbent assay methods (Snap Combo feline leukaemia virus antigen/FIV antibody test kit, IDEXX Laboratories). Western blot analysis was performed on samples in which there was discrepancy between the results. Information regarding breed, age, gender, housing arrangement and health status were recorded for all pet and cattery-confined cats, while the estimated age and current physical condition were recorded for feral cats.

Successful treatment of a localised CDC Group EF-4a infection in a cat.

Organisms classified within the Center for Disease Control (CDC) Group eugonic fermenter (EF)-4a are facultative anaerobic, Gram-negative coccobacilli, thought to be of the family Neisseriaceae. CDC Group EF-4a is considered a component of normal oral flora in cats and dogs and is most commonly isolated from bite injuries of human patients. Most previously reported cases in cats have involved fatal necrotising pneumonia.

Disseminated Mycobacterium avium infection in young cats: overrepresentation of Abyssinian cats.

Disseminated Mycobacterium avium-intracellulare complex (MAC) infection was diagnosed in 10 young cats (1-5 years of age) from Australia or North America between 1995 and 2004. A further two cats with disseminated mycobacteriosis (precise agent not identified) were recognised during this period. Of the 12, 10 were Abyssinian cats, one was a Somali cat and one was a domestic shorthair cat.