Sj Dodkin

Serum protein electrophoresis in 155 cats

All serum protein electrophoresis (SPE) results obtained between 2002 and 2009 from clinical cases presented to the University of Bristol Feline Centre were examined retrospectively. One hundred and fifty-five results met the inclusion criteria. Signalment and final diagnoses were obtained from the case records. Clinical cases were classified as having normal or abnormal SPE results by comparison to reference intervals for SPE created using 77 clinically normal cats. Abnormal results were then further divided according to the specific SPE abnormality. Cases were also categorised, according to the final diagnosis, using the DAMNITV classification system. Of the 155 cases, 136 (87.7%) had abnormal SPE results, most commonly due to a polyclonal increase in gamma globulins. A monoclonal gammopathy occurred in four cats; one with feline infectious peritonitis (FIP), one with lymphoma and two cases of splenic plasmacytoma (one suspected, one confirmed). The most common DAMNITV classification associated with SPE abnormalities was infectious/inflammatory disease (80/136; 58.8%), including 39 cats diagnosed with FIP.

Serum thymidine kinase activity in clinically healthy and diseased cats: a potential biomarker for lymphoma

The thymidine kinases are enzymes that convert deoxythymidine to deoxythymidine monophosphate and have a function in DNA synthesis. Rapidly proliferating cells will have higher levels of thymidine kinase. Serum thymidine kinase activity (sTK) is a useful tumour marker in humans and dogs, with utility as a prognostic indicator in lymphoma. In the current study serum samples were collected from 49 clinically healthy cats, 33 with lymphoma, 55 with inflammatory disease and 34 with non-haematopoietic neoplasia (NHPN). sTK was measured using a radioenzyme assay and a reference interval (1.96 × SD) was established from the clinically healthy cats (<5.5 U/l). Mean sTK activity for healthy cats was 2.2 U/l (range 0.8–8.4, ± SD 1.7). Mean sTK activity for cats with lymphoma was 17.5 U/l (range 1.0–100.0 SD ± 27.4). Mean sTK activity for cats with NHPN was 4.2 U/l (range 1.0–45.0, SD ± 8.6). Mean sTK activity for the inflammatory group was 3.4 U/l (range 1.0–19.6, SD 3.9). Cats with lymphoma had significantly higher sTK activity than healthy cats or cats with inflammatory disease (P <0.0001) and cats with NHPN (P <0.0002). sTK activity is a potentially useful biomarker for feline lymphoma and further study is required to assess its utility as a prognostic indicator.

Measurement of ionized calcium in canine blood samples collected in prefilled and self-filled heparinized syringes using the i-STAT point-of-care analyzer

BACKGROUND Heparinized syringes are commonly used with point-of-care analyzers (eg, i-STAT) to measure ionized calcium (iCa(2+)); however there is little information about the validity of their use in canine patients. OBJECTIVE To examine the suitability of prefilled (40 IU heparin/mL) and self-filled (150 IU heparin/mL) heparinized syringes for iCa(2+) measurements using the i-STAT analyzer. METHODS Forty-seven blood samples were collected from 41 canine patients. Two milliliters of blood were collected into a 2-mL nonanticoagulated (NA) syringe, a commercially available preheparinized (PH) syringe (dry calcium-balanced lithium heparin, 40 IU/mL), and a 2-mL self-filled heparinized (SH) syringe (liquid sodium heparin, 150 IU/mL). iCa(2+) was measured in the sample using the i-STAT analyzer and a wet-reagent analyzer (KoneLab 30i) used as the reference instrument. Data were analyzed using paired t-tests, Pearson correlation coefficient, and Bland-Altman difference plots. RESULTS There was no significant difference between the results obtained from NA and PH syringes using the i-STAT analyzer, and the correlation was excellent (r =.97). The i-STAT values from the SH syringes (mean, 1.07 mmol/L) were significantly lower (P<.001) than those from the NA syringes (mean, 1.38 mmol/L). iCa(2+) was significantly higher with the i-STAT analyzer than with the KoneLab analyzer for both the PH (mean i-STAT, 1.38 mmol/L vs mean KoneLab, 1.30 mmol/L) and SH (mean i-STAT, 1.07 mmol/L vs mean KoneLab, 1.03 mmol/L) samples. CONCLUSIONS Blood samples collected in the PH syringes used in this study can be used interchangeably with those collected in NA syringes for measuring iCa(2+) using the i-STAT analyzer. SH syringes with high-concentration heparin products (5000 IU/mL) are unsuitable for measuring iCa(2+) because they cause clinically significant underestimations. Although there was good correlation between the i-STAT and KoneLab analyzers, the results should be interpreted using analyzer-specific reference intervals.

Transient hyperlipidaemia and anaemia in kittens

Severe fasting hypertriglyceridaemia (5 to 126 mmol/litre) and anaemia (packed cell volume <11 per cent) was observed in 12 litters of kittens around the time of weaning; the entire litter was usually affected, with significant mortality. Lipid analysis revealed marked increases in chylomicrons and moderate increases in very low density lipoproteins. Supportive measures for the treatment of anaemia and weaning on to a low fat diet resulted in a rapid resolution of the clinical signs, anaemia and hypertriglyceridaemia. On recovery, plasma was collected from kittens from five of the affected litters, plus a number of closely related cats and unrelated cats living in the same environment. The lipoprotein lipase (LPL) activity was mildly but significantly lower in the previously affected kittens, their parents and unaffected siblings, than in the unrelated cats. The cats had normal apolipoprotein C-TI function, normal heparin binding activity and no evidence of a circulating inhibitor to LPL. They did not have the LPL gene mutation reported previously in LPL-deficient cats from New Zealand.

Serum protein electrophoresis in 147 dogs

Reference intervals for serum protein electrophoresis (SPE) were created from a group of 75 clinically healthy dogs and compared with SPE results obtained from clinical cases presented to the University of Bristol over an eight-and-a-half-year period. A total of 147 dogs, in which SPE had been performed, had complete case records available and thus met the inclusion criteria. Signalment and final diagnoses taken from the case records and SPE results were divided into normal and abnormal based on the newly established reference intervals. Cases were grouped according to the SPE protein fraction abnormalities and diagnosis using the DAMNITV classification system. Of the 147 cases, 140 (95.2 per cent) had abnormal SPE results. The most common protein fraction abnormality was decreased albumin (59.3 per cent) followed by a polyclonal increase in γ globulins (38.6 per cent). Decreased β-1 globulins and increased β-2 globulins were documented in 36.4 and 30.0 per cent of cases, respectively. The most common DAMNITV classification associated with abnormal SPE results was infectious/inflammatory disease, which was diagnosed in 79 of 140 cases (56.4 per cent). Monoclonal gammopathies were noted in eight dogs (5.7 per cent), and underlying lymphoproliferative disease was present in all cases where a diagnosis was achieved, including multiple myeloma (four dogs), splenic plasmacytoma (one dog), hepatic plasmacytoma (one dog) and lymphoma (one dog).

Comparison of digital and optical hand-held refractometers for the measurement of feline urine specific gravity

Measuring urine specific gravity (USG) is an important component of urine analysis as it evaluates renal concentrating capability. The objective of this study was to quantify the difference in USG values between a hand-held optical analogue refractometer and a cat-specific digital instrument. Urine samples from 55 cats were assessed. There was a statistically significant difference between these two refractometers (P<0.001), with the optical refractometer (mean USG=1.031) consistently reading higher than the digital refractometer (mean USG=1.027). Results for a random subset of the samples (n=10) were compared with urine osmolality and both the optical and digital instruments demonstrated excellent correlation. While an accurate USG reading is important, it is unlikely that the statistical significance between the two instruments is clinically significant and, therefore, unlikely to result in a change in patient evaluation or treatment plans. While both the digital and optimal refractometers are highly correlated to the urine osmolality, making both devices valid for assessment of USG in clinical practice, this digital device is easier to read and eliminates the variability of subjective interpretation.

Comparison of measurements of 18 analytes in canine and feline blood samples using the in‐practice Falcor 350 and the reference KoneLab 30i analysers

OBJECTIVES Falcor 350 (A. Menarini Diagnostics) is a wet-reagent biochemistry analyser that is available for in-house use. The aim of this study was to compare the results produced by this analyser with those obtained by a wet-reagent analyser (KoneLab 30i; Thermo Clinical Labsystems) that served as the reference instrument. METHODS Blood samples from 120 clinical cases (60 dogs and 60 cats) were analysed for 18 analytes (urea, creatinine, total proteins, albumin, creatine kinase, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total bilirubin, amylase, lipase, glucose, triacylglycerol, cholesterol, total calcium, phosphate, sodium and potassium) using both the reference and Falcor instruments. RESULTS Good to excellent correlations (r(s) value) (canine/feline) were identified for urea (0.87/0.86), creatinine (0.96/0.99), total proteins (0.91/0.95), albumin (0.96/0.93), creatine kinase (0.98/0.99), aspartate aminotransferase (0.95/0.98), alanine aminotransferase (0.99/0.99), alkaline phosphatase (0.99/0.98), total bilirubin in dogs (0.88), amylase (0.99/0.87), lipase in dogs (0.88), glucose (0.97/0.98), triacylglycerol (0.93/0.97), cholesterol (0.99/0.99), total calcium (0.88/0.89), phosphate (0.94/0.97) and potassium (0.96/0.97). The correlations for sodium (0.41/0.61), total bilirubin in cats (0.78) and lipase in cats (0.25) were considered unacceptable. CLINICAL SIGNIFICANCE For 13 of the 18 analytes (creatinine, total proteins, albumin, creatine kinase, aspartate aminotransferase, alanine aminotransferase, amylase, glucose, cholesterol, triacylglycerol, phosphate, potassium and urea) in both canine and feline samples, the two instruments produce values that are closely related to each other (excellent correlation) and are sufficiently similar to allow them to be used interchangeably without the need for additional correction factor computations (good agreement). Because of differences in the methodologies, the Falcor results for alkaline phosphatase, total calcium, sodium, lipase and total bilirubin cannot be used interchangeably with those generated by the KoneLab and should be interpreted using reference intervals established from the Falcor analyser.

Comparison of a digital and an optical analogue hand-held refractometer for the measurement of canine urine specific gravity.

Urine specific gravity (USG) is used clinically as a measure of urine concentration, and is routinely assessed by refractometry. A comparison between optical analogue and digital refractometers for evaluation of canine urine has not been reported. The aim of this study was to compare a digital and an optical analogue hand-held refractometer for the measurement of canine USG, and to assess correlation with urine osmolality. Prospective study. Free-catch urine samples were collected from 285 hospitalised adult dogs, and paired USG readings were obtained with a digital and an optical analogue refractometer. In 50 dogs, urine osmolality was also measured using a freezing point depression osmometer. There was a small but statistically significant difference between the two refractometers (P<0.001), with the optical analogue refractometer reading higher than the digital refractometer (mean difference 0.0006, sd 0.0012). Paired refractometer measurements varied by <0.002 in 91.5 per cent of cases. The optical analogue and digital refractometer readings showed excellent correlation with osmolality (r=0.980 and r=0.977, respectively, P<0.001 in both cases). Despite statistical significance, the difference between the two refractometers is unlikely to be clinically significant. Both instruments provide an accurate assessment of USG in dogs.

Biochemical assessment of canine body cavity effusions using three bench-top analysers.

OBJECTIVES To assess the performance of three bench-top chemistry instruments for the analysis of canine effusions. Acceptable results were compared with those obtained by a reference chemistry analyser. METHODS Total protein, albumin, creatinine and bilirubin concentrations were measured in 74 effusions using the VetScanVS2, VetTest8008 and SpotchemEZ analysers. Cholesterol and triglyceride concentrations were also measured by the VetTest and Spotchem. Results were analysed using Westgards error analysis, Spearmans correlation, Bland-Altman plots and Deming regression. Results were considered acceptable when observed total error (TE(obs) ) was less than allowable total error (TE(A) ). RESULTS VetScan error analysis revealed acceptable results for total protein (TE(obs) =1.11, TE(A) =4.7) and creatinine (TE(obs) =42.2, TE(A) =78.1). Correlation was fair for protein (r(s) =0.66) and creatinine (r(s) =0.76), but poor and not significant for bilirubin (r(s) =0.01, P=0.08), precluding error analysis. VetTest error analysis was acceptable for creatinine only (TE(obs) =5.55, TE(A) =25.5). Correlation was good (r(s) =0.81). The difference plot revealed a bias (95% confidence interval) of -1.5 (-37 to 40) and four outliers. The Spotchem did not generate a precise arithmetic value in most (56.9 to 73.6%) samples, precluding further analysis. CLINICAL SIGNIFICANCE Acceptable results were obtained for total protein (VetScan) and creatinine [Vetscan, Vettest (with good correlation)]. The Spotchem is of limited value in canine effusion analysis.