Diagnostic predictivity of transtubular potassium gradient for primary hypoadrenocorticism in hyperkalemic dogs: a cross-sectional study

OBJECTIVES

Transtubular potassium gradient has never been evaluated in the diagnosis of primary hypoadrenocorticism in dogs. The objective of this study is to evaluate the diagnostic utility of transtubular potassium gradient for the diagnosis of primary hypoadrenocorticism in dogs with serum K+  > 5.5 mol/L.

MATERIALS AND METHODS

Cross-sectional study including dogs with primary hypoadrenocorticism and dogs with other disease. Differences in signalment and laboratory parameters between groups were assessed by binary logistic regression modelling. Variables significantly associated with primary hypoadrenocorticism were evaluated for their diagnostic accuracy of this condition by receiver operator characteristic curve analysis and by multivariable logistic regression analysis, respectively.

RESULTS

Dogs with primary hypoadrenocorticism (n=39) were significantly younger than hyperkalemic dogs without primary hypoadrenocorticism (n=41). Moreover they had higher serum and urinary concentrations of Na+ and Na+ :K+ , but lower transtubular potassium gradient than hyperkalemic dogs without hypoadrenocorticism. Serum Na+ (sNa+ ) had the highest diagnostic accuracy (area under the curve [AUC]: 0.87, 95% confidence interval, 0.78 to 0.96), followed by the transtubular potassium gradient (AUC: 0.81, 0.72 to 0.91), however the accuracy of the two AUCs was not statistically different. The transtubular potassium gradient-sNa+ additive index (i.e. transtubular potassium gradient+sNa+ /10) had a greater accuracy (AUC: 0.88, 0.79 to 0.94) than transtubular potassium gradient or sNa+ , although it was not statistically superior to the latter. The multivariable logistic regression model showed that transtubular potassium gradient (adjusted odds ratio [aOR]: 0.51, 0.3 to 0.84), sNa+ (aOR: 0.86, 0.78 to 0.95) and spayed female (aOR: 24.96, 2.32 to 267.66) were associated with primary hypoadrenocorticism.

CLINICAL SIGNIFICANCE

Transtubular potassium gradient-sNa+ additive index can contribute to decision-making on diagnosis of primary hypoadrenocorticism in dogs presenting with hyperkalaemia.

A surveillance system for diseases of companion animals in the Veneto region (Italy)

Experts and international public health organisations stress the lack of surveillance systems for companion animal diseases and the need to implement such surveillance as a priority of the 'One Health' perspective. This paper presents the features of a system for the collection, analysis, interpretation and dissemination of data regarding the health status of pets in the Veneto region (Italy). The system involved the construction of a Web-based database containing the diagnoses of transmissible and non-transmissible diseases of dogs and cats made by veterinarians in their practices, hospitals, kennels and catteries. Each diagnosis constitutes a single record, also containing data on the identification of the individual animal and on several characteristics of epidemiological relevance. The World Health Organization (WHO) 10th revision of the International Classification of Diseases (ICD-10) for human diseases has been adapted to canine and feline diseases to standardise the diagnostic nomenclature. Software has been specifically created for online data entry and data management. The first results show that the main disorders were digestive (21%), dermatological (18%) and cardiovascular (11%) among 1,087 diagnostic records in dogs, and digestive (23%), dermatological (15%) and urinary (14%) among 289 diagnostic records in cats. The main causes of death are represented by cardiovascular (21%) and gastrointestinal (21%) diseases in dogs and by urinary (31%) disorders in cats. At present, no institutional surveillance system for companion animal health exists in Italy, and veterinarians joining this project and sharing the outcomes of their clinical activity are acting on a voluntary basis.

Evaluation of 793/B-like and Mass-like vaccine strain kinetics in experimental and field conditions by real-time RT-PCR quantification

Infectious bronchitis virus (IBV) is a great economic burden both for productive losses and costs of the control strategies. Many different vaccination protocols are applied in the same region and even in consecutive cycles on the same farm in order to find the perfect balance between costs and benefits. In Northern Italy, the usual second vaccination is more and more often moved up to the chick's first d of life. The second strain administration together with the common Mass priming by spray at the hatchery allows saving money and time and reducing animal stress. The present work compared the different vaccine strains (Mass-like or B48, and 1/96) kinetics both in field conditions and in a 21-day-long experimental trial in broilers, monitoring the viral replication by upper respiratory tract swabbing and vaccine specific real time reverse transcription PCR (RT-PCR) quantification. In both field and experimental conditions, titers for all the vaccines showed an increasing trend in the first 2 wk and then a decrease, though still remaining detectable during the whole monitored period. IBV field strain and avian Metapneumovirus (aMPV) presence also was also investigated by RT-PCR and sequencing, and by multiplex real-time RT-PCR, respectively, revealing a consistency in the pathogen introduction timing at around 30 d, in correspondence with the vaccine titer's main decrease. These findings suggest the need for an accurate knowledge of live vaccine kinetics, whose replication can compete with the other pathogen one, providing additional protection to be added to what is conferred by the adaptive immune response.

Full-genome sequencing of porcine circovirus 3 field strains from Denmark, Italy and Spain demonstrates a high within-Europe genetic heterogeneity

Porcine circovirus 3 (PCV3) is a new species of the Circovirus genus, which has recently been associated with different clinical syndromes. Its presence has been reported in different countries of North and South America, Asia and recently also Europe (Poland). However, different from the other continents, no European PCV3 sequence is currently available in public databases. There is a strong need of epidemiological data and full-genome sequences from Europe because of its relevance in the understanding of PCV3 molecular epidemiology and control. To fill this lack of information, samples collected in Denmark, Italy and Spain in 2016 and 2017 were screened for PCV3. Of the Danish samples, 36 of 38 the lymph nodes, six of 20 serum samples and two of 20 lung samples tested positive. Similarly, 10 of 29 lungs, 20 of 29 organ pools, six of 33 sera and one of eight nasal swabs tested PCV3 positive in Italy. Fourteen of 94 serum pools from seven of 14 Spanish farms were also positive. Despite the convenience nature of the sampling prevents any precise prevalence estimation, the preliminary screening of the data from three European countries confirmed a rather wide PCV3 distribution in Europe. Furthermore, the analysis of the six obtained complete European PCV3 genomes and their comparison with the public available sequences seems to support a remarkable worldwide PCV3 circulation. These results underline once more the urgency of more extensive epidemiological studies to refine the current knowledge on PCV3 evolution, transmission, spreading patterns and impact on pig health.

Gamma and Deltacoronaviruses in quail and pheasants from Northern Italy1

In view of the restricted knowledge on the diversity of coronaviruses in poultry other than chicken, this study aimed to investigate the genetic diversity of coronaviruses in quail, pheasant, and partridge from two regions of Northern Italy. To this end, pools of tracheal and cloacal swabs from European quail (Coturnix Coturnix) and intestinal tract from pheasants (Phasianus Colchicus) and partridge (Perdix Perdix) flocks, with or without enteric signs, were collected during 2015. Avian coronavirus (Gammacoronavirus) was detected in quail not vaccinated against Infectious Bronchitis Virus (IBV) and in pheasants vaccinated with an IBV Massachusetts serotype. Based on DNA sequences for the gene encoding the S protein, the avian coronaviruses detected in the quail and pheasant are related to the IBV 793B and Massachusetts types, respectively. However, RNA-dependent RNA polymerase (RdRp) analyses showed the susceptibility of quail also to Deltacoronaviruses, suggesting that quail and pheasant avian coronaviruses share spike genes identical to chicken IBV spike genes and quail might host Deltacoronavirus.

Hemostatic Findings in Ascitic Fluid: A Cross-Sectional Study in 70 Dogs

BACKGROUND

Ascitic fluids of horses and humans have fibrinolytic activity, independent of the underlying mechanism of fluid formation.

OBJECTIVE

To determine whether coagulation and fibrinogenolytic/fibrinolytic activity (ie, low fibrinogen and increased fibrin-fibrinogen degradation products [FDPs], D-dimer, or both) occur in all types of ascitic fluid in dogs.

ANIMALS

A total of 70 client-owned dogs with ascites.

METHODS

In this cross-sectional study, dogs were categorized based on the pathophysiology of fluid formation into 4 groups: transudates due to decreased osmotic pressure, transudates due to increased hydrostatic pressure, exudates, and hemorrhagic ascites. Fibrinogen, FDPs, and D-dimer concentrations were measured and then compared in both ascitic fluid and plasma.

RESULTS

Ten dogs had transudates due to decreased colloid osmotic pressure, 18 had transudates due to increased hydrostatic pressure, 13 had exudates, and 29 had hemorrhagic ascites. Ascitic fibrinogen concentrations (n = 70) were significantly lower (median = 59 mg/dL; range: 59-122 mg/dL) than those in the plasma (median = 168 mg/dL, range: 59-879 mg/dL; P < .0001). Ascitic FDPs concentrations (n = 70) were significantly higher (<5 μg/mL: 3/70 dogs, ≥5 to <20 μg/mL: 11/70 dogs, ≥20 μg/mL: 56/70 dogs) than those in the plasma (<5 μg/mL: 17/70 dogs, ≥5 to <20 μg/mL: 28/70 dogs, ≥20 μg/mL: 25/70 dogs; P < .0001). Ascitic D-dimer concentrations (n = 70) were significantly higher (median = 3.98 μg/mL, range: 0.02-9.19) than those in the plasma (median = 0.11 μg/mL, range: 0.01-4.08; P < .0001). Analysis of the data for each of the 4 different types of ascites showed similar results to those of all the data analyzed together.

CONCLUSIONS AND CLINICAL IMPORTANCE

Ascitic fluid of dogs has evidence of coagulation activation and fibrinogenolytic/fibrinolytic activity and that this phenomenon occurs independent of the underlying mechanism that leads to the formation of ascites.

X-Linked Hereditary Nephropathy in Navasota Dogs: Clinical Pathology, Morphology, and Gene Expression During Disease Progression

X-linked hereditary nephropathy (XLHN) in Navasota dogs is a spontaneously occurring disease caused by a mutation resulting in defective production of type IV collagen and juvenile-onset renal failure. The study was aimed at examining the evolution of renal damage and the expression of selected molecules potentially involved in the pathogenesis of XLHN. Clinical data and renal samples were obtained in 10 XLHN male dogs and 5 controls at 4 (T0), 6 (T1), and 9 (T2) months of age. Glomerular and tubulointerstitial lesions were scored by light microscopy, and the expression of 21 molecules was investigated by quantitative real-time polymerase chain reaction with selected proteins evaluated by immunohistochemistry. No significant histologic lesions or clinicopathologic abnormalities were identified in controls at any time-point. XLHN dogs had progressive proteinuria starting at T0. At T1, XLHN dogs had a mesangioproliferative glomerulopathy with glomerular loss, tubular necrosis, and interstitial fibrosis. At T2, glomerular and tubulointerstitial lesions were more severe, particularly glomerular loss, interstitial fibrosis, and inflammation. At T0, transforming growth factor β, connective tissue growth factor, and platelet-derived growth factor α mRNA were overexpressed in XLHN dogs compared with controls. Clusterin and TIMP1 transcripts were upregulated in later stages of the disease. Transforming growth factor β, connective tissue growth factor, and platelet-derived growth factor α should be considered as key players in the initial events of XHLN. Clusterin and TIMP1 appear to be more associated with the progression rather than initiation of tubulointerstitial damage in chronic renal disease.

Subpopulations in aMPV vaccines are unlikely to be the only cause of reversion to virulence

Avian metapneumovirus (aMPV) infects respiratory and reproductive tracts of domestic poultry, often involving secondary infections, and leads to serious economic losses in most parts of the world. While in general disease is effectively controlled by live vaccines, reversion to virulence of those vaccines has been demonstrated on several occasions. Consensus sequence mutations involved in the process have been identified in more than one instance. In one previous subtype A aMPV candidate vaccine study, small subpopulations were implicated. In the current study, the presence of subpopulations in a subtype B vaccine was investigated by deep sequencing. Of the 19 positions where vaccine (strain VCO3/50) and progenitor (strain VCO3/60616) consensus sequences differed, subpopulations were found to have sequence matching progenitor sequence in 4 positions. However none of these mutations occurred in a virulent revertant of that vaccine, thereby demonstrating that the majority progenitor virus population had not survived the attenuation process, hence was not obviously involved in any return to virulence. However within the vaccine, a single nucleotide variation was found which agreed with consensus sequence of a derived virulent revertant virus, hence this and other undetected, potentially virulent subpopulations, can be involved in reversion. Much deeper sequencing of progenitor, vaccine and revertant may clarify whether problematic virulent subpopulations are present and therefore whether these need to be routinely removed during aMPV vaccine preparation prior to registration and release.

A sensitive, reproducible, and economic real-time reverse transcription PCR detecting avian metapneumovirus subtypes A and B

Use of real-time PCR is increasing in the diagnosis of infectious disease due to its sensitivity, specificity, and speed of detection. These characteristics make it particularly suited for the diagnosis of viral infections, like avian metapneumovirus (AMPV), for which effective control benefits from continuously updated knowledge of the epidemiological situation. Other real-time reverse transcription (RT)-PCRs have been published based on highly specific fluorescent dye-labeled probes, but they have high initial cost, complex validation, and a marked susceptibility to the genetic variability of their target sequence. With this in mind, we developed and validated a SYBR Green I-based quantitative RT-PCR for the detection of the two most prevalent AMPV subtypes (i.e., subtypes A and B). The assay demonstrated an analytical sensitivity comparable with that of a previously published real-time RT-PCR and the ability to detect RNA equivalent to approximately 0.5 infectious doses for both A and B subtypes. The high efficiency and linearity between viral titer and crossing point displayed for both subtypes make it suited for viral quantification. Optimization of reaction conditions and the implementation of melting curve analysis guaranteed the high specificity of the assay. The stable melting temperature difference between the two subtypes indicated the possibility of subtyping through melting temperature analysis. These characteristics make our assay a sensitive, specific, and rapid tool, enabling contemporaneous detection, quantification, and discrimination of AMPV subtype A and B.

Comparative field study to evaluate the performance of three different traps for collecting sand flies in northeastern Italy

Three standard methods for collecting sand flies (sticky trap, CDC light trap, and CO2 trap) were compared in a field study conducted from June to October, 2012, at a site located in the center of a newly established autochthonous focus of canine leishmaniasis in northeastern Italy. Six traps (two sticky traps, two CDC light traps, and two CO2 traps) were activated at the same time for a single night every two weeks during the season of sand fly activity. A total of 5,667 sand flies were collected and 2,213 identified, of which 82.1% were Phlebotomus perniciosus, 17.4% P. neglectus, 0.3% Sergentomya minuta, and 0.2% P. mascitti. The performances of all traps were influenced by their position inside the site, increasing with proximity to the animal shelters. CO2 traps were more attractive for females of P. perniciosus and P. neglectus. CDC light traps showed an intermediate efficiency and were more attractive for P. neglectus, compared to other two traps. Results suggest that in northern Italy the CO2 trap is a suitable sampling method for sand fly monitoring programs that include transmitted pathogen surveillance.

Study on ticks and tick-borne zoonoses in public parks in Italy

A survey on tick density and on tick-borne zoonoses was carried out in four public parks in the outskirts of Imola (northern Italy) from June to October 2006. All stages of Ixodes ricinus and only larvae of Riphicephalus sanguineus were recovered by dragging, performed on 100-m transects. Almost all ticks (99%) were harvested in one park. I. ricinus density (nymphs/100 m(2) ) ranged from 0 in park L to 6.3 in park F. Nymphs and adults of I. ricinus were subjected to PCR for Anaplasma phagocytophilum, Bartonella spp., Borrelia burgdorferi s. l. and Rickettsia spp. The observed prevalences were 38.3% for Bartonella henselae, 5.2% for Bartonella clarridgeiae, 10.4% for B. burgdorferi s. l., 2.6% for Rickettsia helvetica and 13% for Rickettsia monacensis, respectively. No DNA of A. phagocytophilum was found. Acarological risks (AR) were calculated as probabilities of collecting at least one infected nymph per transect. The AR values calculated for the various zoonotic agents were 11.4% for R. helvetica, 27.7% for B. clarridgeiae, 49.7% for B. burgdorferi s. l., 57.2% for R. monacensis and 90.4% for B. henselae, respectively. In this study, B. clarridgeiae was for the first time identified in I. ricinus ticks.

Immunohistochemical study of phospho-Stat3-ser727 expression in feline mammary gland tumours

We describe the expression of pStat3-ser727 (signal transducer and activator of transcription 3 phosphorylated on serine 727) in normal, hyperplastic and neoplastic feline mammary gland tissue assessed by immunohistochemistry in 56 cats. The samples included 4 normal mammary non-lactating tissues, 13 hyperplastic lesions (9 lobular and 4 fibroepithelial) and 39 tumours (6 benign and 33 carcinomas). For immunohistochemistry, tissue sections were incubated with anti-pStat3-ser727 monoclonal antibodies and visualized with EnVision-DAB polymer. pStat3-ser727 positivity was quantified in a semi-quantitative manner, differentiating cytoplasmic and nuclear localization. Intense anti-pStat3-ser727 immunoreactivity was detected in epithelial neoplastic cells and in the fibro-component in two fibroepithelial hyperplastic lesions. The immunostaining was dot-like in the cytoplasm and homogeneous in the nuclei in both benign and malignant lesions. Statistically significant relations were observed between nuclear expression of pStat3-ser727 and the pleomorphism score (p = 0.006), mitotic activity (p < 0.0001), and histological grade (p < 0.0001). In contrast, no significant correlations were observed for cytoplasmic pStat3-ser727. These findings add new and interesting information on the potential role of the phosphorylated form of Stat3 in malignant lesions.

Expression of Stat3 in Feline Mammary Gland Tumours and its Relation to Histological Grade

The expression of Stat3 (signal transducer and activator of transcription 3) in normal and neoplastic feline mammary gland tissue was assessed by immunohistochemistry in 72 cats. The samples included 3 normal nonlactating mammary tissues, 17 hyperplastic lesions (11 lobular and 6 fibroepithelial) and 52 neoplasms (5 benign and 47 malignant). For immunohistochemistry, tissue sections were incubated with anti-Stat3 monoclonal antibody and visualized with EnVision-DAB polymer. Stat3 positivity was assessed in a semiquantitative manner. Normal mammary tissue showed occasional cytoplasmic and nuclear positivity, although the number of positive cells was lower than in the hyperplastic specimens. In neoplastic tissue, high numbers of neoplastic cells with a moderate to intense cytoplasmic and nuclear positivity were observed. Selected variations in the staining pattern correlated with malignancy. Moreover, a positive association was seen between the histological grade and the Stat3 score (p < 0.0001; correlation coefficient 0.750). A linear regression model showed a positive association between mitotic count and Stat3 expression (p < 0.001). These results further support published data found in humans regarding to the relation between the expression of Stat3 and malignancy.

Proposal of Health Information System (HIS) as tool for the epidemiological surveillance of leishmaniasis in urban areas

In recent years leishmaniasis has become a serious Public Health problem in Italy. The coexistence of infected dogs, vectors and humans, makes urban areas suitable environment for the spread of this zoonotic disease. With the purpose to improve the current system for the control of leishmaniasis in urban areas, the authors report their experiences carrying out a Health Information System (HIS) for the surveillance of the disease in the city of Messina. The HIS project is built on a dataset containing geographical data on urban environment, census tracts at parish level and data of human and canine leishmaniasis cases reported in the last years. The HIS allows the spatial representation of the disease occurrence and can be used as a novel epidemiological tool to perform area-based surveillance.

[A minimum medical GIS database (MMDb) for Europe]

Geographic information systems (GIS) and remote sensing (RS) technologies are being used increasingly to study the spatial and temporal patterns of some parasitic diseases of medical and veterinary importance. At the same time, the incorporation of GIS in this field shows the scarcity of the data and images available, which sometime discourage researchers that still look at GIS as a system too difficult and unusable for medical study. Aware of this problem and supported by success of earlier MMDb's for Africa, Asia and South America, the authors' aim is to construct and offer an MMDb for Europe. The initial MMDb is composed with vector images covering an area situated from -11 degrees-70 degrees N to 58 degrees-30 degrees E. Specifically, data layers include: a) Global Moderate-Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) 16 days at 250 m spatial resolution designed to provide consistent spatial and temporal comparisons of vegetation conditions, supplied in the MMDb as seasonal and annual composite images from 2000 to 2003, b) MODIS Land Surface Temperature (LST) calculated from daytime and nighttime observations at 8 day intervals at 1 km spatial resolution, supplied in the MMDb as seasonal and annual composites images for day (maximum) temperatures, night (minimum) temperatures from 2000 to 2003, c) GTOPO30 Digital Elevation Model (DEM) at 1 km spatial resolution, d) United States Geological Survey (USGS) Land use/land cover scheme, e) USGS actual and potential evapotranspiration supplied for all 12 months as a grid at 50 km spatial resolution, f) USGS precipitation showing the amount of rainfall for all 12 months supplied as a grid at 50 km spatial resolution, g) USGS shapefiles of administrative and political boundaries, cities, towns, villages, lakes, rivers, streams, road, railroads and more. The MMDb projection will be in geographic latitude-longitude, decimal degree format. This global format is most commonly used for public access map database resources and can be readily re-projected as needed for compatibility with various national mapping systems. There is no "required" software, and end users need only common commercial GIS software packages that have mutual import-export functions. Additionally, the MMDb is meant to be a dynamic resource that end users may improve and modify with other regional data.

A study of the progress of the Aujeszky's disease control programme in Italy using survival analysis

A 3-year study (1997-2000) was performed on 294 swine herds from Italy, where a National Programme of Control of Aujeszky's Disease (AD) based on compulsory vaccination has been operative since 1997. Aim of the study was to evaluate the progress of this control programme using a survival approach applied to gE-seropositive herds at the beginning of the programme. The cumulative proportion of herds still gE-seropositive at the end of the study was 0.57. No significant difference in the probability of becoming gE-seronegative during the study period was found between herds of different type (breeding versus farrow-to-finish) whereas significant differences were seen between herds from different areas. The Cox's proportional hazards regression, performed on data from 79 herds, showed that the only risk factor significantly associated with a higher probability of becoming gE-seronegative is again the geographical location. Other risk factors considered in the analysis were: type of enterprise, type of replacement of animals, herd size, pig and pig herds densities around the farm, distance from the nearest pig herd and year of beginning of the vaccination with a gE-deleted vaccine.