Retrospective study evaluation of DGGR lipase for diagnosis, agreement with pancreatic lipase and prognosis in dogs with suspected acute pancreatitis.

OBJECTIVES: Activity of 1,2-o-dilauryl-rac-glycero-3-glutaric acid-(6'-methylresorufin) ester (DGGR) lipase is considered to be more pancreas specific than traditional lipase assays. The aim of this study was to evaluate the diagnostic performance of DGGR lipase activity for suspected acute pancreatitis in dogs and to assess its prognostic usefulness. METHODS: Retrospective study of case records for suspected acute pancreatitis based on clinician-stated diagnosis, point-of-care and quantitative canine pancreas-specific lipase (cPL) results and consistent ultrasonographic features. Diagnostic performance of DGGR lipase was assessed by receiver-operating characteristic curve analysis, agreement by Cohen's kappa (κ) and prognostic value by multiple regression analysis. RESULTS: Median DGGR lipase activity was significantly (P < 0.001) higher in dogs with suspected acute pancreatitis [93.7 (range, 11.0-2853.0) U/L (n = 158)] compared to those with no evidence of pancreatitis [range, 20.9 (6.7-89.0) U/L (n = 356)]. A DGGR lipase activity >42.15 U/L had the best combined diagnostic sensitivity (81.0%) and specificity (92.1%). Previously established cut-offs (>130 and >80 U/L) had sensitivities of 40.5 and 43.0%, and specificities of 100 and 99.7%, respectively. There was near perfect (κ = 0.821) and substantial (κ = 0.751) agreement between DGGR lipase activity >42.15 U/L and quantitative cPL concentrations ≥200 and ≥400 µg/L, respectively. DGGR lipase activity but not quantitative cPL concentration was statistically (P = 0.043, odds ratio = 0.999) predictive of discharge but clinical utility is questionable. CLINICAL SIGNIFICANCE: Using DGGR lipase at the lower cut-off could provide an additional test for supporting a diagnosis of acute pancreatitis in dogs particularly if cPL results are not available. Larger studies are required to more fully assess its value in prognostication.

Qualitative and semiquantitative assessment of thyroid hormone binding proteins in greyhounds and other dog breeds.

Total thyroxine (T4) concentrations are lower in healthy greyhounds compared to most other non-sighthound breeds. In humans, variations in the structure or concentration of the major thyroid hormone binding proteins are responsible for most reported differences between total T4 concentrations in healthy individuals from different ethnic groups or other subpopulations. The aim of this study was to determine if such variations are also responsible for the lower total T4 concentrations in greyhounds. The predicted protein sequences of thyroxine-binding globulin (TBG), transthyretin and albumin were determined in liver tissue from a euthyroid greyhound with decreased T4 concentration and a Jack Russell terrier using reverse-transcriptase PCR. Sequences were compared to each other and online reference sequences. Serum proteins from 21 greyhounds and 21 non-sighthound dogs were separated by denaturing electrophoresis and immunoblots probed with polyclonal antibodies to human TBG and transthyretin. Reactive bands were quantified by densitrometry, expressed relative to the mean of reference samples included in each gel. Serum albumin concentrations were measured using a commercially-available assay. Several SNPs were identified but none was thought likely to explain the lower total T4 concentrations in greyhounds. There was no significant difference between the quantity of any of the binding proteins in serum from greyhounds and non-sighthound dogs. However, total T4 and transthyretin concentrations were highly correlated in the greyhound group (r = 0.73, P = 0.0002). Variation in the sequence of thyroid hormone binding proteins is not responsible for low greyhound total T4 concentrations. Further evaluation of the role of transthyretin is warranted.

Antimicrobial resistance increased over an 8-year period in Enterobacteriaceae cultured from canine urine samples.

OBJECTIVES: The aims of the present study were to describe the prevalence of positive urinary bacterial culture in dogs, to identify the most commonly isolated microorganisms and to analyse changes in antimicrobial susceptibility patterns over time. MATERIAL AND METHODS: A retrospective case series was performed using culture and susceptibility results from canine urine samples collected between January 2010 and December 2017. The presence or absence of infection, identity of the bacterium with heaviest growth, and susceptibility profile were recorded for each sample. Trends in the frequency of positive culture and antimicrobial resistance were assessed by Poisson regression modelling. Prevalence rate ratio and 95% confidence interval were reported for resistance to each antimicrobial. RESULTS: A positive urine culture was documented in 771 (22.5%) of 3420 samples. Escherichia coli was the most commonly isolated microorganism. There was no significant increase in the frequency of positive bacterial culture over the study period (prevalence rate ratio 0.98; 95% confidence interval: 0.92 to 1.0). Overall, there was an increase in antimicrobial resistance within Enterobacteriaceae from 5.2 to 35.6%. The prevalence of multidrug-resistant bacteria varied from year to year throughout the study period. However, the Poisson regression model identified a significant increase in the frequency of multidrug-resistant Enterobacteriaceae over this period, averaging approximately 22% per year (prevalence rate ratio 1.22, 95% confidence interval: 1.06 to 1.42). CLINICAL SIGNIFICANCE: The significant increase in antimicrobial resistance observed in this study is concerning and may have implications for veterinary and public health. Appropriate measures, such as antibiotic stewardship programmes, should be implemented to address increasing antimicrobial resistance.

A comparison of canine whole and intact parathyroid hormone concentrations as measured by different assays.

OBJECTIVES: To compare an intact immunoradiometric parathyroid hormone assay with (1) a non-isotopic technique; and, (2) a whole parathyroid hormone immunoradiometric assay. MATERIALS AND METHODS: Intact parathyroid hormone concentrations were measured using immunoradiometric (Scantibodies) and chemiluminescent (Immulite 2000) assays. Whole parathyroid hormone concentration was measured using an immunoradiometric assay (Scantibodies). RESULTS: A total of 48 and 47 samples, respectively, were used to compare immunoradiometric and chemiluminescent intact parathyroid concentrations and intact and whole parathyroid hormone concentrations by immunoradiometric assays. Using chemiluminescence, 39 (81.3%) samples had intact parathyroid hormone concentrations at or below the reported limit of detection of the assay (0.3 pmol/L). Intact [6.3 (2.0 to 95.5) pmol/L] and whole [3.3 (0.8 to 125.2) pmol/L] immunoradiometric parathyroid hormone concentrations exhibited excellent correlation. CLINICAL SIGNIFICANCE: Not all parathyroid hormone assays perform similarly. The chemiluminescent assay in this study cannot be recommended for use in dogs. The immunoradiometric intact parathyroid hormone assay proved to be a more reliable method. Given the correlation between intact and whole parathyroid hormone concentrations, it remains unclear which one is superior for routine clinical decision-making.

Canine MAS1: monoallelic expression is suggestive of an imprinted gene.

Imprinted genes are epigenetically modified in a parent-of-origin dependent manner and as a consequence are differentially expressed, with one allele typically expressed while the other is repressed. In canine, the insulin like growth factor 2 receptor gene (IGF2R) is imprinted with predominant expression of the maternally inherited allele. Because imprinted genes usually occur in clusters, we examined the allelic expression pattern of the gene encoding the canine Mas receptor (MAS1), which is located upstream of IGF2R on canine chromosome 1 and is highly conserved in mammals. In this report we describe monoallelic expression of canine MAS1 in the neonatal umbilical cord of several individuals and we identify the expressed allele as maternally inherited. These data suggest that canine MAS1 is an imprinted gene.

Hydrocortisone in the management of acute hypoadrenocorticism in dogs: a retrospective series of 30 cases.

OBJECTIVES: The objectives of this study were to describe the efficacy, outcome and adverse effects of intravenous hydrocortisone and fluid therapy for the management of acute hypoadrenocorticism in dogs. METHODS: A retrospective review of dogs with primary hypoadrenocorticism receiving intravenous hydrocortisone and fluid therapy was performed. RESULTS: Thirty newly-diagnosed dogs were included. There was an excellent clinical response, with all dogs surviving to discharge within a median of 2 days. In 23 cases with complete data, the mean rate of change of sodium over 24 hours was 0·48 (±0·28) mmol/L/hour, while the mean rate of change of potassium was -0·12 (±0·06) mmol/L/hour. Circulating potassium concentration normalised in 68·4% and 100% of cases of by 12 and 24 hours, respectively. Additional treatment for hyperkalaemia was not found necessary. Plasma sodium concentration increased by >12 mmol/L/24 hours on 7 of 23 (30·4%) occasions. One dog exhibited associated temporary neurological signs. CLINICAL SIGNIFICANCE: Intravenous hydrocortisone infusion and fluid therapy for the management of acute hypoadrenocorticism is associated with a rapid resolution of hyperkalaemia and is well tolerated with few adverse effects. Regular electrolyte monitoring is required to ensure that rapid increases in sodium concentration are avoided.

Clinical, haematological, cytokine and acute phase protein changes during experimental Babesia gibsoni infection of beagle puppies.

Babesia gibsoni is a haemoprotozoan parasite of emerging global importance. The clinical presentation of babesial infections is diverse and the systemic inflammatory response induced by infection is considered to be a major feature of the pathophysiology of canine babesiosis. An experimental case-controlled longitudinal study was conducted to assess the clinical, haematological, cytokine and acute phase protein changes that occur during experimental B. gibsoni infection of beagle puppies. Infected dogs became transiently pyrexic and anaemic, intermittently neutropenic and transiently, but profoundly, thrombocytopenic, although this had no apparent adverse clinical effect. Experimental B. gibsoni infection also induced an acute phase response, characterised by a marked increase in the concentration of C-reactive protein, which was delayed in onset following infection but preceded the detection of peripheral parasitaemia. Experimental B. gibsoni infection was also associated with marked increases in the concentration of multiple cytokines which were also delayed in onset following infection and occurred subsequent to the detection of peripheral parasitaemia and the acute phase response. This study furthers our understanding of the immune response that occurs during babesial infections and the role that systemic inflammation plays in the pathophysiology of canine babesiosis.

Right-sided congestive heart failure in a dog because of a primary intracavitary myocardial lymphoma.

CASE REPORT: A 9-year-old female intact Cocker Spaniel was presented with a history of acute-onset dyspnoea and abdominal distension of 3 days' duration. Ultrasonography revealed pleural, peritoneal and pericardial effusions. Abdominal fluid analysis was consistent with a modified transudate. Echocardiography revealed a large, hypoechoic space-occupying mass within the right atrium. The dog was euthanased and the postmortem examination showed a solid, 40 × 35 × 20 mm broad-based mass arising from the right atrial wall and occluding approximately 90% of the right atrial lumen. Histopathology revealed myocardial lymphoma. There were histologically similar, focal nodules in the lung parenchyma without involvement of other extracardiac sites. There was gross and histological evidence of hepatic congestion and marked distension of the caudal vena cava, consistent with secondary right-sided congestive heart failure. CONCLUSION: This case highlights the need to consider lymphoma as a differential diagnosis for an intra-atrial mass and as a cause of congestive heart failure in the dog.

Major histocompatibility complex class II alleles and haplotypes associated with non-suppurative meningoencephalitis in greyhounds.

Non-suppurative meningoencephalitis is a breed-restricted canine neuroinflammatory disorder affecting young greyhounds in Ireland. A genetic risk factor is suspected because of the development of disease in multiple siblings and an inability to identify a causative infectious agent. The aim of this study was to examine potential associations between dog leucocyte antigen (DLA) class II haplotype and the presence of the disease. DLA three locus haplotypes were determined in 31 dogs with non-suppurative meningoencephalitis and in 115 healthy control dogs using sequence-based typing (SBT) methods. All dogs were unrelated at the parental level. Two haplotypes (DRB1*01802/DQA1*00101/DQB1*00802 and DRB1*01501/DQA1*00601/DQB1*02201) were significantly (P = 0.0099 and 0.037) associated with the presence of meningoencephalitis, with odds ratios (95% confidence interval) of 5.531 (1.168-26.19) and 3.736 (1.446-9.652), respectively. These results confirm that there is an association between DLA class II haplotype and greyhound meningoencephalitis, suggesting an immunogenetic risk factor for the development of the disease. Greyhound meningoencephalitis may be a suitable model for human neuroinflammatory diseases with an immunogenetic component.

Comparison of manual and laboratory PCV and total protein using EDTA and lithium heparin canine samples.

OBJECTIVES: To evaluate if lithium heparin (LiH) and potassium ethylenediaminetetraacetic acid (EDTA) can be used interchangeably to obtain packed cell volume (PCV) and total protein by refractometry (TPr), and to compare those values with laboratorywderived haematocrit (Hct) and total protein (TP) concentration, respectively, in canine blood samples. METHODS: Blood samples taken in LiH and EDTA were manually assessed for PCV and TPr. Results were correlated to Hct and TP. RESULTS: 238 EDTA and corresponding serum/LiH samples were obtained. There was excellent correlation but statistically significant difference between LiH and EDTA PCV (n=43). LiH and EDTA TPr (n=43) were excellently correlated without significant difference. PCV and Hct (n=176) were excellently correlated without significant difference. LiH (n=105) and serum (n=133) TP was respectively fairly or well correlated with TPr but with significant differences. An increase in cholesterol of 1 mmol/L was associated with a mean independent increase in TPr of approximately 1 g/L. CLINICAL SIGNIFICANCE: LiH and EDTA can be used interchangeably for TPr. Although TPr and serum/plasma TP were correlated, there were statistically significant differences that could impact on clinical decision making. TPr is increased by cholesterol but this alone could not account for the magnitude of the difference observed.

Assessment of the value of quantitative thyroid scintigraphy for determination of thyroid function in dogs.

OBJECTIVE: To assess the value of thyroid scintigraphy to determine thyroid status in dogs with hypothyroidism and various non-thyroidal illnesses. METHODS: Thyroid hormone concentrations were measured and quantitative thyroid scintigraphy performed in 21 dogs with clinical and/or clinicopathological features consistent with hypothyroidism. RESULTS: In 14 dogs with technetium thyroidal uptake values consistent with euthyroidism, further investigations supported non-thyroidal illness. In five dogs with technetium thyroidal uptake values within the hypothyroid range, primary hypothyroidism was confirmed as the only disease in four. The remaining dog had pituitary-dependent hyperadrenocorticism. Two dogs had technetium thyroidal uptake values in the non-diagnostic range. One dog had iodothyronine concentrations indicative of euthyroidism. In the other, a dog receiving glucocorticoid therapy, all iodothyronine concentrations were decreased. Markedly asymmetric technetium thyroidal uptake was present in two dogs. All iodothyronine concentrations were within reference interval but canine thyroid stimulating hormone concentration was elevated in one. Non-thyroidal illness was identified in both cases. CLINICAL SIGNIFICANCE: In dogs, technetium thyroidal uptake is a useful test to determine thyroid function. However, values may be non-diagnostic, asymmetric uptake can occur and excess glucocorticoids may variably suppress technetium thyroidal uptake and/or thyroid hormone concentrations. Further studies are necessary to evaluate quantitative thyroid scintigraphy as a gold standard method for determining canine thyroid function.

Clinical and clinicopathological features of non-suppurative meningoencephalitis in young greyhounds in Ireland.

The clinical and clinicopathological features of non-suppurative meningoencephalitis in 30 greyhounds were reviewed. The dogs were from 21 separate litters, comprised both sexes (16 males and 14 females) and ranged in age from five to 18 months. In 14 (66.7 per cent) litters, more than one case was suspected or confirmed, and the number of siblings affected within individual litters ranged from one to seven. Clinical signs were progressive and varied from five days to 12 months in duration; 12 dogs had signs of two weeks' duration or less. The rate of progression of signs was variable. Common features included dullness or lethargy (22), altered behaviour (21), proprioceptive and postural reaction deficits (18), circling (17), ataxia (17), decreased appetite (15) and weight loss (13). No consistent haematological or biochemical abnormalities were identified and serology failed to implicate Toxoplasma gondii or Neospora caninum. Cerebrospinal fluid analysis revealed mild or moderate mononuclear pleocytosis in 12 (70.6 per cent) of 17 dogs. No definitive antemortem diagnosis could be made in any affected dog.

Thyroid hormone abnormalities and outcome in dogs with non-thyroidal illness.

OBJECTIVES: To document thyroid hormone abnormalities in dogs with non-thyroidal illness and identify markers of prognostic value. METHODS: Circulating total and free thyroxine, total triiodothyronine and thyrotropin concentrations were measured in 196 dogs with non-thyroidal illness. Clinical signs, previous medications and outcome were recorded in each case. Data were analysed to determine endocrine prognostic factors, and to document the prevalence of thyroid hormone abnormalities. RESULTS: Total triiodothyronine, and total and free thyroxine concentrations were decreased in 75.9, 34.7 and 4.5 per cent of cases, respectively. Dogs which were euthanased had significantly decreased total triiodothyronine, and total and free thyroxine concentrations compared with those which made a full recovery. Total triiodothyronine concentrations were significantly lower in dogs that were euthanased compared with those which made a partial recovery. CLINICAL SIGNIFICANCE: Thyroid hormone concentrations may be used as prognostic indicators in dogs with non-thyroidal illness. Low triiodothyronine syndrome may be more common in dogs than previously recognised.

Thyroid hormone concentrations in young, healthy, pretraining greyhounds.

Total thyroxine (T(4)) concentrations were below the non-breed-specific reference range in 42 of 46 healthy young greyhounds (91.3 per cent) and 16 (34.8 per cent) were at or below the limit of detection of the assay. Free T(4) concentrations were below the standard reference interval in 20.5 per cent of the animals and 13 per cent were at or below the limit of detection of the assay. In contrast, all the dogs' total tri-iodothyronine concentrations were within or above the non-breed-specific reference range and 67 per cent were within the upper half. All the dogs' thyroid stimulating hormone concentrations were within the non-breed-specific reference range. The results show that young greyhounds have markedly lower total and free T(4) concentrations than other breeds, and neither analyte can reliably be used to investigate the hypothyroidism in this breed as values were found below the limit of detection of each respective assay.