Repeat patient testing-quality control compared to commercial quality control material for the Sysmex XT-2000iV hematology analyzer in a multi-site veterinary laboratory.

BACKGROUND: Quality control material (QCM) for hematology in veterinary laboratories is limited, and repeat patient testing quality control (RPT-QC) is an alternative method using excess matrix-specific samples. OBJECTIVES: This study aimed to determine if median differences between RPT-QC analyses for each time interval for RBC, HGB, HCT, and WBC were the same, determine if unified RPT-QC limits can be applied to a network of veterinary laboratories, compare the performance of RPT-QC to commercial QCM for the reference analyzer and evaluate the experience over a 4 month period and design, improve and implement an automated spreadsheet for RPT-QC data management. METHODS: The potential to unify individual analyzer RPT-QC limits for red blood cells (RBC), hematocrit (HCT), hemoglobin (HGB), and white blood cells (WBC) on multi-site Sysmex XT-2000-iV analyzers was explored by a difference of means test and confidence interval determination for the median difference for each network analyzer in comparison to the network reference analyzer. User experience of an automated RPT-QC data management Excel spreadsheet was collected by user feedback during monthly meetings. Numbers of out-of-control results and the root causes for these for RPT-QC were compared against those of a commercial QCM over a 4-month period. RESULTS: Differences between individual analyzer RPT-QC limits were too large to allow for unification of network limits. The automated spreadsheet successfully highlighted out-of-control events for RPT-QC. Trends or shifts were more frequent for commercial QCM based on observed performance and a 1-2.5 s QC rule than for RPT-QC. Following routine troubleshooting, RPT-QC out-of-control events were resolved with an alternative RPT-QC sample indicating random error associated with excessive deterioration. Use of an automated spreadsheet for recording RPT-QC, documentation and troubleshooting of out-of-control events, and collating monthly summary calculations were considered an asset in laboratory quality management. CONCLUSIONS: RPT-QC can be successfully implemented and integrated into a multi-site veterinary laboratory. Individual analyzer RPT-QC limit generation is recommended. The deterioration of commercial QCM caused shifts or trends in QC results, which initiated more repeat analyses and investigations than did RPT-QC.

Estimating short and longer-term exposure of domestic cats to dietary iodine fluctuation.

Hyperthyroidism is a common endocrinopathy of domestic felines. In humans, toxic nodular goitre is pathophysiologically similar to feline hyperthyroidism and can be caused by chronically low or fluctuating dietary iodine intake. The aetiopathogenesis of feline hyperthyroidism is not known, but chronically low or fluctuating dietary iodine intake is likely common. This study assessed habitual iodine intake in domestic cats by: (1) conducting a dietary survey involving 361 owners of 549 cats, (2) analysing iodine content of 119 cat feeds, 38 urine and 64 hair samples and (3) assessing variation in iodine content of eight cat feeds over 4-6 different batches. Owners varied their cats feed regularly, usually on a day-to-day basis and often between wet and dry feeds with differing flavours. The majority (78%; 93 of 119) feeds for cats were within the guideline range for iodine. Of the 22% (n = 26 feeds) that were not compliant, the majority (n = 23) were below the nutritional minimum value with most (n = 16) being dry kibble. Iodine content of feeds did not vary considerably between types of feed or feed packaging, but variation between different batches of the same feed was 14-31%. Hence, urine iodine in cats also varied markedly. Cats being treated for hyperthyroidism had lower hair iodine. In conclusion, a survey assessing how domestic cats are fed, together with an analysis of commercial cat feeds suggests that domestic cats are likely to experience chronically low or fluctuating dietary iodine intake. The latter is supported by wide variation in urine iodine content.

Results of urinary bacterial cultures and antibiotic susceptibility testing of dogs and cats in the UK.

OBJECTIVES: Bacterial urinary tract infections are a common diagnosis in small animal practice and antibiotics are often administered empirically. The aim of this study was to investigate the aetiology and antibiotic resistance of uropathogens in dogs and cats in the UK. MATERIALS AND METHODS: Retrospective study of uroculture and antibiotic susceptibility testing results (n=808) by disk diffusion processed at a veterinary pathology laboratory between 2011 and 2012. RESULTS: Significant bacteriuria was detected in 18.4% of samples from dogs and 10.0% from cats, most of which (>90%) yielded a single organism. Escherichia coli was the most prevalent bacterial species (54.7% and 55.6% of feline and canine isolates, respectively) followed by Proteus mirabilis in dog samples (22.7%) and Enterococcus spp. in cat samples (23.2%). Approximately a third of E. coli isolates were resistant to ampicillin but resistance was much lower among Enterococcus spp. and P. mirabilis. Resistance to amoxicillin-clavulanic acid also seemed to be emerging, particularly in E. coli (almost 20% resistant). In contrast, resistance to trimethoprim-sulfamethoxazole for uropathogens remained <13% except for P. mirabilis (19.4%). Overall, fluoroquinolones showed the best in vitro activity (resistance mostly below 10% for enrofloxacin and marbofloxacin). CLINICAL SIGNIFICANCE: Our results provide evidence of the emergence of resistance to antibiotics commonly used to treat bacterial urinary tract infections. Continued monitoring of the patterns of antibiotic resistance in uropathogens is needed to assess the adequacy of recommendations on the empiric therapy of these infections.

Increasing antimicrobial resistance in clinical isolates of Staphylococcus intermedius group bacteria and emergence of MRSP in the UK.

Frequencies of antimicrobial resistance were determined amongst 14,555 clinical Staphylococcus intermedius group (SIG) isolates from UK dogs and cats to estimate resistance trends and quantify the occurrence of meticillin-resistant Staphylococcus pseudintermedius (MRSP). Reports from two diagnostic laboratories (13,313 general submissions, 1242 referral centre only submissions) were analysed retrospectively (2003/2006-2012). MRSP were defined by phenotypic resistance to meticillin and concurrent broad ß-lactam resistance; a subset was confirmed genetically (SIG-specific nuc and mecA). Trends were analysed by Cochran-Armitage test. Resistance remained below 10 per cent for cefalexin, amoxicillin-clavulanic acid and the fluoroquinolones. Increasing resistance trends were seen in both laboratories for ampicillin/amoxicillin (both P<0.001), cefovecin (both P<0.046) and enrofloxacin (both P<0.02). Resistance to cefalexin increased over time in referral hospital isolates (P<0.001) to clindamycin (P=0.01) and trimethoprim-sulfamethoxazole (P=0.001) amongst general laboratory submissions. Overall, 106 MRSP were isolated (0.7 per cent of submissions) including 32 (2.6 per cent of submissions, all genetically confirmed) from the referral centre population (inter-laboratory difference P<0.001). Against a background of widely susceptible SIG isolates, a new trend of increasing resistance to important antimicrobials was identified overtime and the emergence of MRSP from UK clinical cases was confirmed. Attention to responsible use of antibacterial therapy in small animal practice is urgently needed.

Best practice for the pharmacological management of hyperthyroid cats with antithyroid drugs.

Pharmacological management of feline hyperthyroidism offers a practical treatment option for many hyperthyroid cats. Two drugs have been licensed for cats in the last decade: methimazole and its pro-drug carbimazole. On the basis of current evidence and available tablet sizes, starting doses of 2·5 mg methimazole twice a day and 10 to 15 mg once a day for the sustained release formulation of carbimazole are recommended. These doses should then be titrated to effect in order to obtain circulating total thyroxine (TT4) concentrations in the lower half of the reference interval. Treated cases should be monitored for side-effects, especially during the first months of treatment. Some side-effects may require discontinuation of treatment. At each monitoring visit, clinical condition and quality of life should also be evaluated, with special attention to possible development of azotaemia, hypertension and iatrogenic hypothyroidism. When euthyroidism has been achieved, monitoring visits are recommended after 1 month, 3 months and biannually thereafter. Cats with pre-existing azotaemia have shorter survival times. However, development of mild azotaemia during the initial course of treatment, unless associated with hypothyroidism, does not appear to decrease survival time. The long-term effects of chronic medical management require further study.

Detection of endoparasites with zoonotic potential in dogs with gastrointestinal disease in the UK.

We report a substantial prevalence study in symptomatic pet dogs of important zoonotic parasitic enteric infections. A total of 4526 dogs which had a faecal sample submitted to a diagnostic laboratory in the UK between 2003 and 2005 were included in the study. The most common parasite was Giardia spp., which was found in 380/4526 dogs (8.4%, 95% CI 7.6-9.2%). Surprisingly, Cryptosporidium spp. infection was detected in only 29/4526 (0.6%, 95% CI 0.4-0.9%). Toxocara canis was found in 63/4526 dogs (1.4%; 95% CI 1.1-1.8%). Prevalence of Giardia (P < 0.001) was significantly higher in dogs <12 months of age, with nearly one-fifth of all symptomatic dogs under 6 months being infected with Giardia. Some seasonality was detected with a higher prevalence of Cryptosporidium oocyst shedding found from October to December. These data are of importance for veterinarians in judging the likelihood of enteric parasitic infection in an individual with clinical signs. Moreover, they provide information to direct future work in determining the risk to the human population from parasitic zoonoses of dogs.

Association of canine hypothyroidism with a common major histocompatibility complex DLA class II allele.

Dogs exhibit a range of immune-mediated conditions including a lymphocytic thyroiditis which has many similarities to Hashimoto's thyroiditis in man. We have recently reported an association in Doberman Pinschers between canine hypothyroidism and a rare DLA class II haplotype that contains the DLA-DQA1*00101 allele. We now report a further series of 173 hypothyroid dogs in a range of breeds where a significant association with DLA-DQA1*00101 is shown.

Immunologic responses and adverse reactions to Freund's-adjuvanted porcine zona pellucida immuno-contraceptives in domestic cats.

A vaccine of native PZP with Freund's adjuvant has been widely used in zoo and wild ungulates, but safety in felids has not been evaluated. General health, immune response, and ovarian histology were assessed in five domestic cats vaccinated with PZP-Freund's and five cats given Freund's adjuvant alone. Peak antibody titers occurred 3 weeks after the third vaccination, and no ovarian lesions were present 6 months after vaccination. Seven cats developed extensive granulomatous reactions at injection sites, lymph nodes, and multiple visceral organs including lungs and brain. Persistent hypercalcemia and compromised renal function occurred in three cats with elevated serum calcitriol of probable macrophage origin. One cat died from an injection site sarcoma. Because of these severe adverse reactions, Freund's adjuvant is contraindicated in cats, and other adjuvants for PZP vaccines should be tested in cats for adverse reactions before use.

Influence of a high fibre diet on glycaemic control and quality of life in dogs with diabetes mellitus.

A study was undertaken to evaluate a high fibre diet used in the management of 10 dogs with naturally occurring insulin-dependent diabetes mellitus. Following baseline measurements of health and glycaemic control, the dogs were fed a canned diet containing a blend of insoluble and soluble dietary fibres and were monitored during the ensuing four months. Switching to the high fibre diet was associated with significantly lower mean 24-hour and postprandial plasma glucose concentrations, which were maintained over the study period. The high fibre diet was also associated with significant reductions in plasma concentrations of fructosamine, glycated haemoglobin, free glycerol and cholesterol, and there were significant improvements in dog activity and demeanour. Bodyweight declined during the fourth month of feeding the diet, which is likely to have resulted from underfeeding relative to increased activity. The results indicate that a high fibre diet can significantly improve glycaemic control and quality of life in dogs with diabetes mellitus.

Update on the diagnosis and treatment of disorders of calcium regulation.

The availability of PTH, iCa, PTHrP, and 25OHD assays for evaluation of calcium abnormalities in companion animals has been well received [table: see text] by clinicians and diagnosticians. Use of these assays has heightened awareness that some of these disorders are more common than originally thought. Also, there is added insight of alterations of calcium homeostasis as a consequence of other illness or environmental factors such as diet. Animal counterparts of other disorders of calcium metabolism in people are likely to be identified, and use of these assays should play a significant role. As already emphasized, the foundation of using [table: see text] these assays is first assessing whether the calcium abnormality is of a parathyroid-dependent or parathyroid-independent classification.

Lymphocytic thyroiditis.

Lymphocytic thyroiditis is a common canine condition that can lead to functional hypothyroidism. It is associated with more than 50% of cases of canine hypothyroidism. Evidence in human beings and experimental situations suggests that it is a disease of defective immunoregulation, but specific investigation of the molecular pathogenesis of the naturally occurring disease in dogs has not yet been carried out. The condition is heritable in those breeds that have been studied, and progression to hypothyroidism, if it occurs, can be slow. Factors that influence the progression from subclinical thyroiditis to hypothyroidism in dogs are still to be identified, but excessive iodine intake is an important factor in other species.

Fructosamine concentration and resistance to natural, predominantly Teladorsagia circumcincta infection.

Fructosamine concentrations reflect protein status and because infection with Teladorsagia circumcincta can induce a relative protein deficiency, we examined the usefulness of fructosamine concentrations as markers of the intensity of infection in naturally infected lambs. Fructosamine concentration was a heritable trait and variation in fructosamine concerntrations was associated with differences in body weight, and a variety of parasitological variables; animals with increased fructosamine concentrations grew more quickly, had increased faecal egg counts in one of the three study years, had decreased pepsinogen concentrations and decreased IgA activity against 4th-stage larvae of T. circumcincta. Fructosamine concentrations were also associated with variation in the subsequent acquisition of nematodes and in the length of adult female T. circumcincta; lambs with increased fructosamine concentrations had fewer nematodes but the mean length of adult female T. circumcincta was longer. Therefore fructosamine concentrations are potentially useful indicators of the severity of nematode infection and may predict magnitude of subsequent infection.

Patient positioning using detailed three-dimensional surface data for patients undergoing conformal radiation therapy for carcinoma of the prostate: a feasibility study.

PURPOSE: The increasing complexity of radiotherapy highlights the need for accurate setup. This paper assesses the potential of position corrections, derived from the three-dimensional (3D) surface of the patient, in reducing positioning errors in patients undergoing conformal radiation therapy of the prostate. METHODS AND MATERIALS: Twenty patients undergoing conformal radiation therapy for prostate cancer had planning computed tomography (CT) scans and then weekly treatment CT scans over the course of their treatment. Patients were positioned on the CT table using three coplanar tattoo marks used for patient setup on the accelerator. Surfaces were computed from the planning CT (planning surface), and the treatment CT (treatment surfaces). Using a surface matching utility, the planning and treatment 3D surfaces were compared. The prostate was implicitly localized based on surface matching of the external contour and by matching the bony anatomy. The resultant prostate displacement after correction was assessed for the two localization methods. RESULTS: Correcting patient position via the surface comparisons reduced the standard deviation of prostate displacement with respect to the patient isocenter in the lateral and anterior/posterior directions. In the lateral direction, prostate and surface motion was highly correlated (r = 0.96). In the anterior/posterior direction the corrections from the surface data were as effective as those derived from the bony anatomy. CONCLUSION: Detailed surface data can aid the positioning of patients receiving conformal radiation therapy to the prostate by reducing the displacement of the target from the intended treatment position. This study shows that surface corrections can be as effective as those derived from bony anatomy, and may be exploited where definition of bony anatomy is difficult.

The influence of relative resistance and urea-supplementation on deliberate infection with Teladorsagia circumcincta during winter.

The consequences for lambs of infection over the winter with Teladorsagia circumcincta were quantified by deliberate, trickle infection of selected animals at 7 months of age. Infected and control uninfected animals were each allocated into four groups, relatively resistant animals on a normal diet, relatively resistant animals on an isocaloric diet supplemented with urea, and relatively susceptible animals on the same two diets. Resistance and susceptibility was assessed by faecal egg counts following natural infection during the summer preceding the deliberate infection. During the deliberate infection egg counts remained low and most parasites recovered at necropsy were inhibited larvae. Nonetheless, infection reduced weight gain, decreased albumin and fructosamine concentrations and provoked a noticeable pepsinogen and eosinophil response. As most larvae were inhibited these responses may have been largely a consequence of immuno-inflammatory responses in the host rather than the direct action of parasites themselves. Relatively resistant animals on the supplemented diet allowed fewer larvae to establish and had higher fructosamine concentrations, higher albumin concentrations and decreased pepsinogen responses. Therefore, a combination of relatively resistant sheep and nutritional supplementation appears most efficient at controlling infection.

3D dynamic body surface sensing and CT-body matching: a tool for patient set-up and monitoring in radiotherapy.

Recent advances in radical broad-beam conformal radiotherapy for disease at non-rigid sites suggest that the treatment room set-up of patients should be performed using the CT-plan digital body surface as a reference standard. In effect, the CT-plan surface is a "virtual shell" and should be used as such. To do this requires 3D body surface information to be captured live in the treatment room and then manipulated for comparison with the CT virtual shell. To address this situation, a near real-time prototype opto-electronic dynamic 3D surface sensor has been developed and equipped with a novel software utility for visualizing and matching the disparate surfaces arising from planning and treatment environments. Using the CT virtual shell and height-maps produced by the sensor, a two-phase 3D positioning strategy for patient set-up and monitoring is described. Phase one is an image-guided manual "approach". Phase two is automated "docking" using simulated annealing to determine optimum set-up corrections. The concepts and implementation are illustrated using archival patient data and an anthropomorphic phantom "patient" in a treatment room environment.

Animation and radiobiological analysis of 3D motion in conformal radiotherapy.

PURPOSE: To allow treatment plans to be evaluated against the range of expected organ motion and set up error anticipated during treatment. METHODS: Planning tools have been developed to allow concurrent animation and radiobiological analysis of three dimensional (3D) target and organ motion in conformal radiotherapy. Surfaces fitted to structures outlined on CT studies are projected onto pre-treatment images or onto megavoltage images collected during the patient treatment. Visual simulation of tumour and normal tissue movement is then performed by the application of three dimensional affine transformations, to the selected surface. Concurrent registration of the surface motion with the 3D dose distribution allows calculation of the change in dose to the volume. Realistic patterns of motion can be applied to the structure to simulate inter-fraction motion and set-up error. The biologically effective dose for the structure is calculated for each fraction as the surface moves over the course of the treatment and is used to calculate the normal tissue complication probability (NTCP) or tumour control probability (TCP) for the moving structure. The tool has been used to evaluate conformal therapy plans against set up measurements recorded during patient treatments. NTCP and TCP were calculated for a patient whose set up had been corrected after systematic deviations from plan geometry were measured during treatment, the effect of not making the correction were also assessed. RESULTS: TCP for the moving tumour was reduced if inadequate margins were set for the treatment. Modelling suggests that smaller margins could have been set for the set up corrected during the course of the treatment. The NTCP for the rectum was also higher for the uncorrected set up due to a more rectal tissue falling in the high dose region. CONCLUSION: This approach provides a simple way for clinical users to utilise information incrementally collected throughout the whole of a patient's treatment. In particular it is possible to test the robustness of a patient plan against a range of possible motion patterns. The methods described represent a move from the inspection of static pre-treatment plans to a review of the dynamic treatment.

Serum fructosamine concentrations in hyperthyroid cats.

Serum fructosamine concentrations were measured in 35 healthy cats and in 30 hyperthyroid cats before and 30 days after curative radioiodine ((131)I) treatment. Hyperthyroid cats were divided into those with 30 day post-treatment total thyroxine (T4) concentrations within (EuT4) or below (HypoT4) the reference range. The median (semi-interquartile range, SIR) fructosamine concentration was significantly lower in hyperthyroid compared with healthy cats (295. 0 (18.5) micromol l(-1)) both before (254.0 (27.6) micromol l(-1)) and after (268.5 (28.0) micromol l(-1)) treatment (P < 0.001 in each case). (131)I therapy was associated with increases in serum fructosamine (mean increase 20.4 micromol l(-1), P = 0.039) and total protein (6.3 g l(-1), P < 0.002) in the HypoT4 group and in globulin concentration in both EuT4 (5.9 g l(-), P < 0.002) and HypoT4 (5.2 g l(-1), P = 0.023) groups. There were no direct relationships between the observed elevations in fructosamine concentration and those in total protein or globulin concentrations suggesting that the effect may be due to reduced rates of protein turnover. Reduced values may need to be considered when interpreting serum fructosamine concentrations for monitoring the degree of glycaemic control in diabetic cats with concurrent hyperthyroidism.

Prevalence of autoantibodies to thyroglobulin in dogs with nonthyroidal illness.

OBJECTIVE: To evaluate a thyroglobulin autoantibody (TgAA) assay and determine a diagnostic threshold. SAMPLE POPULATION: Serum samples from dogs with various endocrine abnormalities and from 30 obese adult female Beagles. PROCEDURE: TgAA were determined by use of the ELISA. Six experiments were done: 1, definition of positive results for TgAA using samples from normal and T3 autoantibody (T3AA) positive dogs; 2, establishment of prevalence of positive results in 91 clinically normal dogs; 3, evaluation of positive results for sera from dogs with nonthyroidal illnesses; 4, testing of samples from dogs with primary hypothyroidism but absence of T4AA or T3AA, or both; 5, determination of prevalence of false-negative results in dogs that are T4AA and/or T3AA positive, which were (18 dogs) or were not (22 dogs) receiving L-thyroxine replacement therapy; and 6, examination of thyroid biopsy specimens from 18 dogs (8 TgAA positive and 10 TgAA negative). RESULTS: Positive results were defined as at least twice (200%) the optical density of the negative-control sample. False-positive results were obtained for only 3.4% of 146 dogs with nonthyroidal illness. Thirty-seven percent of dogs with primary hypothyroidism, but no evidence of T4AA or T3AA, or both, were TgAA positive. False-negative results were found in 1 of 22 and 2 of 18 T3AA-positive dogs with and without thyroid replacement therapy, respectively. Thyroid biopsy specimens from 8 TgAA-positive dogs had evidence of lymphocytic thyroiditis, whereas those from 10 TgAA-negative dogs did not. CONCLUSION AND CLINICAL RELEVANCE: The assay is sensitive and specific for identification of lymphocytic autoimmune thyroiditis in dogs, and has potential for aiding early diagnosis of thyroiditis in dogs and identifying dogs likely to perpetuate hypothyroidism in breeding programs.

Pharmacokinetics of a porcine insulin zinc suspension in diabetic dogs.

Ten dogs with naturally occurring diabetes mellitus were injected with a highly purified porcine insulin zinc suspension at a dose according to their expected requirement. Plasma insulin and glucose concentrations were measured at two-hourly intervals over 24 hours following injection. There were either one or two peaks in plasma insulin concentration: one at about four hours (mean 4.3 +/- 1.3 [SD]) and another at about 11 hours (mean 11 +/- 1.85) after the injection. The second insulin peak was seen in only eight dogs. Persistence of elevated plasma insulin concentrations ranged from 14 to 24 hours (mean 17.4 +/- 3.65). These results compare favourably with those published for other intermediate-acting insulin preparations used to treat canine diabetes mellitus and suggest that this preparation has useful properties for the successful management of many canine diabetics.

Fructosamine measurement in ponies: validation and response following experimental cyathostome infection.

Validation of an assay for measurement of fructosamine in equine serum and plasma utilised blood samples collected from 24 British native breed ponies. The results indicated that fructosamine can be measured easily using an assay which is precise and accurate. Paired plasma and serum fructosamine measurements were highly correlated, however, greater variations were observed within serum compared with those in plasma. A reference range for fructosamine in plasma was calculated to be 256.9 +/- 60.6 mumol litre-1 (mean +/- 2 SD). In order to assess the fructosamine response following experimental cyathostome infection, nine British native breed ponies were allocated to one of three groups: Group 1 (3.9 million third-stage cyathostome larvae (L3) over a nine-week-period), Group 2 (3.15 million L3 over seven weeks) and Group 3 (uninfected controls). From four weeks prior to infection, blood was obtained, once weekly, from all animals for measurement of plasma fructosamine, plasma albumin and serum globulin concentrations. Plasma fructosamine concentrations decreased in all infected ponies post-infection due to enteric protein loss and/or altered protein composition and/or increased protein turnover.