Symptomatic Dogs Research Articles

Dermatophytes Isolated From Dogs and Cats Suspected Dermatophytoses in Istanbul, Turkey Within A 15-Year-Period: An Updated Report

The present research was aimed to determine the prevalence of dermatophytes isolated from symptomatic dogs and cats, within a 15-year-period, in the city of Istanbul, Turkey. Dermatological specimens were collected from 1504 dogs and 846 cats, which were presented clinical signs of ringworm. Direct microscopy and mycological cultures were performed. The fungal growth rate was detected at 8.2% and 22.8% from dogs and cats, respectively. Microsporum canis was the most frequently isolated species followed by Trichophyton spp., M. gypseum , T. mentagrophytes , M. nanum , other Microsporum spp. moreover T. tonsurans . The cats less than two-year age and more than ten-year age showed a statistically significant higher isolation rate of infection ( p < 0.05). There were no statistically significant differences between the age of the dogs and the dermatophyte isolation rate and between the gender of the dogs and cats and the dermatophyte isolation rate. As a conclusion, the data suggest an updated report on local epidemiology and define potential etiologic agents.

Relationship of peripheral blood mononuclear cells miRNA expression and parasitic load in canine visceral leishmaniasis.

Visceral leishmaniasis (VL) in humans is a chronic and often fatal disease if left untreated. Dogs appear to be the main reservoir host for L. infantum infection, however, in many regions other canids such as jackals, foxes, wolves and other mammals, such as hares or black rats, have been implicated as wild reservoirs. Most dogs cannot form an effective immune response against this infection, and this could be modulated by small non-coding RNAs, called microRNAs, responsible for post-transcriptional control of gene expression. Here, we evaluated the expression of miRNAs in peripheral blood mononuclear cells (PBMC) of symptomatic dogs naturally infected with Leishmania (L.) infantum (n = 10) and compared to those of healthy dogs (n = 5). Microarray analysis revealed that miR-21, miR-424, miR-194 and miR-451 had a 3-fold increase in expression, miR-192, miR-503, and miR-371 had a 2-fold increase in expression, whereas a 2-fold reduction in expression was observed for miR-150 and miR-574. Real-time PCR validated the differential expression of miR-21, miR-150, miR-451, miR-192, miR-194, and miR-371. Parasite load of PBMC was measured by real-time PCR and correlated to the differentially expressed miRNAs, showing a strong positive correlation with expression of miR-194, a regular positive correlation with miR-371 expression, and a moderate negative correlation with miR-150 expression in PBMC. These findings suggest that Leishmania infection interferes with miRNAs expression in PBMC, and their correlation with parasite load may help in the identification of therapeutic targets in Canine Visceral Leishmaniasis (CVL).

Efficacy of ivermectin to control Strongyloides stercoralis infection in sheltered dogs

In dogs, information on treatments against S. stercoralis infection is rare and anecdotal. The aim of the present work was to evaluate the treatment outcome of S. stercoralis natural infection in sheltered dogs. Furthermore, based on the potential risk of infection, people working in the infected shelter were also tested. Seventeen sheltered dogs positive to S. stercoralis using the Baermann test were treated with ivermectin 200 μg/kg/sid/os for two consecutive days. Only two dogs showed clinical signs suggestive of strongyloidiasis (diarrhea, weigh loss) at diagnosis. All dogs showed consistently negative results for S. stercoralis at weekly monitoring after treatment using both the direct microscopy and Baermann test. Real-time PCR confirmed negative results at the last follow up 2 months after treatment. Serology performed at the first diagnosis showed that 82% and 41% of dogs were positive for S. stercoralis using an IFAT (titres ranging from 1:40 to 1:320) and ELISA, respectively. Two months after treatment, IFAT titres were strongly reduced in all animals. The results of clinical pathological laboratory tests at diagnosis in the positive dogs were within normal ranges, except for the two symptomatic dogs. Serum collected from two out of 14 shelter workers tested positive with titres 1:20 and 1:40 for S. stercoralis using an IFAT. Results of the study confirm that ivermectin was an effective treatment option to control S. stercoralis infection in dogs. Shelter workers are at risk of infection with S. stercoralis, thus the application of correct deworming protocols to reduce the environmental infective larval burden is essential to protect dogs and probably also shelter workers from the risk of infection.

Canine visceral leishmaniasis: Detection of Leishmania spp. genome in peripheral blood of seropositive dogs by real-time polymerase chain reaction (rt-PCR)

Visceral leishmaniasis (VL) is a zoonosis caused by the protozoa of the genus Leishmania. Among the species, L. infantum and/or L. infantum (chagasi) are the most important species affecting the Americas. Domestic dogs are the main reservoir of the parasite and participate effectively in the parasite' transmission cycle. The Canine Visceral Leishmaniasis Control Program (PCLV) adopted in Brazil present as strategies the vector control, health education and serological diagnosis of CVL in dogs followed by culling of the seropositive ones. The resolution to eliminate seropositive dogs by euthanasia, when necessary, are the most controversial and least accepted by society. The diagnostic methods for canine visceral leishmaniasis, currently indicated and approved in Brazil by the Ministry of Health from Brazil are the Dual Path Platform (DPP)® as a screening test and the Enzyme immunoassay test (ELISA®). This study aimed to verify the presence of Leishmania spp. DNA in peripheral blood samples of dogs presenting positive serological results byDPP® and ELISA® tests,throughreal-time polymerase chain reaction (rt-PCR), using the pair of primers 150–152 already described. For this purpose, were collected blood samples from 185 seropositive dogs among them, 41 (22%) exhibited some clinical signal of disease, whereas 144 (78%) was asymptomatic. The animals were also analyzed according to gender, race and hair size. According to the results of rt-PCR, it was observed that among the185 seropositive dogs analyzed, only 132 (71%) presented positive results for CVL and 53 (29%) presented negative results. From this, 41/41 symptomatic dogs were positive (100%), while among the asymptomatic dogs, 91/144 were positive (63, 2%) and 53/144 were negative (36, 8%). Concerning the hair size of seropositive dogs, we found that 41 (22%) had long hair, while 144 (78%) had short hair. No statistical significance occurred between the results of rt-PCR, ELISA and DPP tests and the profile of the animals (gender, size of the dogs and hair size), probably due to the small number of samples and the sampling differences of each profile. But statistical significance occurred between the results of rt-PCR and the clinical evaluation, since the rt-PCR was positive in all symptomatic dogs. Thus, through these results, we reached at the following question, which may contribute to an important current debate: the dogs presenting CVL seropositive diagnosis confirmed by tests distributed by the Ministry of Health were in reality ill or were they seropositive by living in an endemic area of the disease? Would these asymptomatic seropositive dogs spread the disease to the inhabitants even presenting a low parasite charge circulating in the blood.

Validation of the Dual-path Platform chromatographic immunoassay (DPP® CVL rapid test) for the serodiagnosis of canine visceral leishmaniasis.

BACKGROUND Visceral leishmaniasis is a major public health challenge in South America, and dogs are its main urban reservoir. OBJECTIVE Validation of the canine Dual-path Platform immunoassay for canine visceral leishmaniasis (DPP® CVL) for a sample set composed of 1446 dogs from different Brazilian endemic areas. METHODS A well-defined reference standard by means of parasitological culture, immunohistochemistry, and histopathology was used. Animals were classified as asymptomatic, oligosymptomatic, or symptomatic. Sensitivity and specificity were assessed as a single set and in clinical groups. A reproducibility assessment of the tests was conducted using the Kappa (κ) index at three different laboratories (A, B, and C). FINDINGS Overall, 89% sensitivity and 70% specificity were obtained for the entire sample set. Analysis of the clinical groups showed a gradual decrease in the sensitivity and an increase in the specificity with the reduction of clinical signs in the dogs that were assessed, reaching a sensitivity of 75% (42.8-94.5%) among asymptomatic dogs and lower specificity of 56% (46.2-66.3%) among symptomatic dogs. Inter-laboratory agreement was substantial (κAB= 0.778; κAC= 0.645; κCB= 0.711). MAIN CONCLUSIONS The test performance is somewhat dependent on canine symptomatology, but such influence was less evident than in previous studies. Favourable results for sensitivity and specificity can be obtained even in asymptomatic animals; however, caution is needed in these evaluations, and the results suggest that the immunochromatographic test may be further improved for better investigation in asymptomatic dogs. The results obtained confirm the usefulness of DPP® CVL for application in serological surveys.

Validation of the Dual-path Platform chromatographic immunoassay (DPP® CVL rapid test) for the serodiagnosis of canine visceral leishmaniasis

BACKGROUND Visceral leishmaniasis is a major public health challenge in South America, and dogs are its main urban reservoir. OBJECTIVE Validation of the canine Dual-path Platform immunoassay for canine visceral leishmaniasis (DPP® CVL) for a sample set composed of 1446 dogs from different Brazilian endemic areas. METHODS A well-defined reference standard by means of parasitological culture, immunohistochemistry, and histopathology was used. Animals were classified as asymptomatic, oligosymptomatic, or symptomatic. Sensitivity and specificity were assessed as a single set and in clinical groups. A reproducibility assessment of the tests was conducted using the Kappa (κ) index at three different laboratories (A, B, and C). FINDINGS Overall, 89% sensitivity and 70% specificity were obtained for the entire sample set. Analysis of the clinical groups showed a gradual decrease in the sensitivity and an increase in the specificity with the reduction of clinical signs in the dogs that were assessed, reaching a sensitivity of 75% (42.8-94.5%) among asymptomatic dogs and lower specificity of 56% (46.2-66.3%) among symptomatic dogs. Inter-laboratory agreement was substantial (κAB= 0.778; κAC= 0.645; κCB= 0.711). MAIN CONCLUSIONS The test performance is somewhat dependent on canine symptomatology, but such influence was less evident than in previous studies. Favourable results for sensitivity and specificity can be obtained even in asymptomatic animals; however, caution is needed in these evaluations, and the results suggest that the immunochromatographic test may be further improved for better investigation in asymptomatic dogs. The results obtained confirm the usefulness of DPP® CVL for application in serological surveys.

High accuracy of an ELISA test based in a flagella antigen of Leishmania in serodiagnosis of canine visceral leishmaniasis with potential to improve the control measures in Brazil - A Phase II study.

BackgroundCanine Visceral leishmaniasis (CVL) is a serious public health problem, thus for its control, the Ministry of Health in Brazil recommends the rapid diagnosis and euthanasia of seropositive dogs in endemic areas. Therefore, our group had previously selected six recombinant proteins (rLci1, rLci2, rLci4, rLci5, rLci8, and rLci12) due to their high potential for CVL diagnostic testing. The present study aims to produce an immunodiagnostic test using the aforementioned antigens, to improve the performance of the diagnosis of CVL recommended by Brazilian Ministry of Health.Methodology/Principal findingsTo evaluate the recombinant proteins in the serological assays, positive and negative samples were selected based on parasitological test (culture) and molecular test (qPCR) of splenic aspirate. Initially, we selected 135 dog serum samples, 73 positives (symptomatic and asymptomatic) and 62 negatives to screen recombinant proteins on ELISA platform. Then, for rLci5 ELISA validation, 361 serum samples collected in a cross-sectional study were selected, being 183 positives (symptomatic and asymptomatic) and 178 negatives. In the screening of the recombinant proteins, rLci5 was the only protein to present a performance statistically higher than the performance presented by EIE-LVC test, presenting 96% (IC 95%; 85–99%) vs. 83% (IC 95%; 69–92%) of sensitivity for symptomatic dogs, 71% (IC 95%; 49–97%) vs. 54% (IC 95%; 33–74%) for asymptomatic dogs and 94% (IC 95%; 83–99%) vs, 88% (IC 95%; 76–95% of specificity. Thus, the rLci5 protein was selected to compose a final ELISA test. Validation of rLci5 ELISA showed 87% (IC 81–91%) of sensitivity, 94% (IC 95%; 90–97%) of specificity and 90% accuracy. Testing the EIE-LVC with the same validation panel, we observed a lower performance when compared to ELISA rLci5 (sensitivity of 67% (IC 95%; 59–74%), specificity of 87% (IC 95%; 81–92%), and accuracy of 77%). Finally, the performance of current CVL diagnostic protocol recommended by Brazilian Ministry of Health, using DPP-LVC as screening test and EIE-LVC as confirmatory test, was compared with a modified protocol, replacing EIE-LVC by rLci5 ELISA. The current protocol presented a sensitivity of 59% (IC 95%; 52–66%), specificity of 98% (IC 95%; 95–99%) and accuracy of 80% (IC 95%; 76–84%), while the modified protocol presented a sensitivity of 71% (IC 95%; 63–77%), specificity of 99% (IC 95%; 97–100%) and accuracy of 86% (IC 95%; 83–89%).ConclusionThus, we concluded that rLci5 ELISA is a promising test to replace EIE-LVC test and increase the diagnostic performance of CVL in Brazil.

Leishmania infantum Virulence Factor A2 Protein: Linear B-Cell Epitope Mapping and Identification of Three Main Linear B-Cell Epitopes in Vaccinated and Naturally Infected Dogs.

In Brazil, canine visceral leishmaniasis (CVL) is caused by Leishmania infantum, presenting a broad spectrum of clinical manifestations. Dogs are the main parasite reservoir in urban areas and canine cases precede human infection. Currently, A2 protein based Leish-Tec® vaccine is the only vaccine commercially available against CVL in Brazil. Considering that the main screening and confirmatory tests of canine infection are serological, it is possible that the antibody response elicited after vaccination interfere with diagnosis, leading to the inability to distinguish between vaccinated and infected animals. In order to identify the specific B-cell response induced after vaccination, A2 protein sequence was screened for main linear B-cell epitopes using in silico prediction (Bepipred) and immunological confirmation by ELISA. Three amino acid sequences were described as potential B-cell epitopes (SV11-SAEPHKAAVDV, PP16-PQSVGPLSVGPQSVGP, and VQ34-VGPLSVGPQSVGPLSVGPLSVGPQAVGPLSVGPQ). Specific IgG ELISAs were performed in sera of 12 immunized dogs living in non-endemic areas, followed for up to 1 year after immunization. The results were compared with those obtained in a group of 10 symptomatic and 10 asymptomatic CVL dogs. All predicted epitopes were confirmed as linear B-cell epitopes broadly recognized by sera from studied dogs. Total IgG ELISAs demonstrated distinct patterns of response between peptides in the immunized and CVL groups. VQ34 peptide was recognized by the majority of sera from vaccinated and symptomatic dogs, and increases after vaccination. PP16 induced low levels of specific IgG that increased 1 year after immunization. Interestingly, a low frequency of reactivity was found against SV11 in naturally infected dogs (symptomatic and asymptomatic), while 83.3% of vaccinated dogs presented positive responses 1 year after immunization. The two animals in the vaccinated group that did not respond to SV11 1 year after immunization presented positive serology both 30 days and 6 months after immunization. In summary, we identified three main linear B-cell epitopes in A2 based vaccine. Moreover, the humoral response against SV11 presented marked differences between infected and Leish-Tec vaccinated dogs, and should be further investigated, in large trials, to confirm its potential as a serological marker able to distinguish between infected and vaccinated dogs.

Comparative analysis of the Leishmania infantum-specific antibody repertoires and the autoantibody repertoires between asymptomatic and symptomatic dogs

Leishmania (L.) infantum-infected dogs may present with a large range of clinical signs, from apparently healthy with no or few (asymptomatic dogs, AD) to several clinical signs indicators of active infection (symptomatic dogs, SD). The present study is justified by the conflicting reports describing that either L. infantum-specific IgG1 or IgG2 antibodies may be used as isotype marker of the asymptomatic infection status and by the lack, to our knowledge, of previous analysis of the IgG sub-classes autoantibody repertoires of Leishmania-infected dogs. On the basis of clinical evaluation and laboratory testing (IFAT, parasitological examination of Giemsa-stained lymph node smears, L. infantum antigens-ELISA of total (Tot) IgG), 131 dogs were categorized as SD, asymptomatic seronegative (AND) or seropositive dogs (APD) from surrounding areas, and as negative control dogs (CTD). ELISA based on leishmanial native antigens or recombinant LACK and LeIF proteins showed that SD produce higher levels of specific Tot IgG, IgG1 and IgG2 antibodies than APD, and that for both clinical stages, the antibody titers of IgG2 isotype were constantly higher than those of the IgG1. The seroprevalences of Tot IgG, IgG2 did not differ between APD and SD groups (97 and 97% in SD; 100 and 96% in APD, respectively) whereas that of IgG1 was slightly lower in SD (88% of APD versus 82% of SD). The autoantibody repertoires were analyzed by ELISA using HEp-2 extracts, ds-DNA, human albumin and transferrin as self-antigens and by Western blot using HEp-2 proteins. ELISA results’ indicated that APD develop higher levels of IgG1 autoantibodies, and higher seroprevalence (50% and 26% in APD and SD, respectively), contrasting with lower levels and seroprevalences of Tot IgG and IgG2 (43 and 68% for APD; 100 and 74% for SD). Interestingly, SD showed a stronger IgG1 and particularly IgG2 reactivity with transferrin, an iron-binding protein, than APD and AND. Western blotting experiments produced heterogeneous IgG1 and IgG2 inter- and intra-groups reactivity profiles towards HEp-2 proteins, to identify a specific antigenic profile. Generated data from competitive HEp-2-ELISA using leishmanial antigens as inhibitors were in favor that IgG1 antibodies are predominantly autoantibodies to self-antigens in APD whereas they are mainly cross-reactive (Leishmania/self-antigens) in SD.

Geographical variation in clinical signs and prevalence of Leishmania sp. infection among dogs in Fortaleza, Ceará State, Brazil

Background: Leishmaniosis are anthropozoonosis caused by protozoa of the genus Leishmania, representing a complex of diseases with significant diversity epidemiological and clinical spectrum and can affect 40% of the canine population. Infected dogs may be asymptomatic or may develop canine leishmaniasis (CL), a severe and progressive disease associated with the appearance of clinical signs. Serological tests are frequently used for screening of dogs, however, these techniques present limitations in terms of reproducibility and specificity. In this way, information on the geographical distribution and prevalence of CL is essential to the implementation of appropriate control measures. Therefore, the aim of this study was to determine geographical variations in clinical signs and prevalence of Leishmania sp. infections from dogs in Fortaleza, Ceara state, Brazil. Materials, Methods & Results: Bone marrow samples of 2829 domestic dogs were collected by puncture for parasitological diagnosis of canine leishmaniasis (CL), being considered positive by the presence of Leishmania sp. All dogs were examined and clinical signs were classified as score 0: no clinical signs, score 1: skin lesions, score 2: visceral signs and score 3: skin lesions + visceral signs. Kruskal-Wallis (P <0.05) was used to compare the scores and parasitological diagnosis among the seven regions of Fortaleza. So, it was observed that 72% of dogs were positive and the regions I and V had the highest prevalence (78.3% and 80% respectively), no significant differences among the seven regions. Asymptomatic dogs represented 55% of infected dogs, and the main clinical sign, among symptomatic dogs (45%), was skin lesion, visualized in 43% of dogs. Furthermore, 70% of all dogs had ectoparasites. Discussion: These results show that, despite of the campaign against the disease, there is no great progress in the control of visceral leishmaniasis in the urban areas like Fortaleza, which present an easy access in the fight against the disease. The diagnostic in dogs based in the Indirect Fluorescent Antibody Test (IFAT) associated to others factors, like irregular serological inquiry and no-treated performer personal, perhaps made possible the permanence of susceptibility animals in this area, beyond of the high number of asymptomatic and no-identified dogs. In this study, it was observed that 55% of dogs were asymptomatic, without showing evidence of risk of transmission to human population, escaping from controlling methods. From this we can imply that most of these dogs to LC are asymptomatic and the prevalence did not differ significantly in different regions of Fortaleza, requiring equal attention throughout the city. Moreover, our results demonstrate that Fortaleza city has favorable areas for the maintenance of the parasite cycle, with a high risk of transmission to human and canine population, and it requires special attention because of the large number of asymptomatic cases. Therefore, it is necessary to control the population of asymptomatic dogs with more efficient controlling methods, with the change of methodology of serological screening raising the number of detected dogs, reducing the diagnostic time and the use of diagnostic techniques with levels of specificity higher.

Behavior of two Leishmania infantum strains-evaluation of susceptibility to antimonials and expression of microRNAs in experimentally infected J774 macrophages and in BALB/c mice.

Strains of the same Leishmania parasite species, isolated from different host organisms, may exhibit unique infection profiles and induce a change in the expression of microRNAs among host macrophages and in model host mice. MicroRNAs (MiR) are endogenous molecules of about 22 nucleotides that are involved in many regulatory processes, including the vertebrate host immune response. In this respect, the infectivity and susceptibility to antimonials of two L. infantum strains, BH46, isolated from human, and OP46, isolated from symptomatic dog, were characterized in J774 macrophages and BALB/c mice. Parasite burden was assessed in the liver, spleen, and bone marrow using the serial limiting dilution technique. A higher parasite burden was observed in the spleen and bone marrow of animals infected with OP46 compared to BH46 strain. Our results also showed that OP46 was less susceptible to the antimonials. In addition, miR-122 and miR-155 expression was evaluated in the liver and J774 macrophages, and in spleens from infected animals, respectively. An increase was observed in the expression of miR-155 in J774 macrophages infected with both strains compared to uninfected cells, with a higher expression in cells infected with OP46. However, no difference in the expression of miR-122 and miR-155 was observed in the infected animals. Thus, this study shows that OP46 was more infective for mice, it caused a higher increase in miR-155 expression in infected macrophages and was less susceptible to the antimonials evaluated. These data suggest that alteration in miR-155 level likely plays a role in regulating the response to L. infantum.

Immunodetection of hepatic stellate cells in dogs with visceral leishmaniasis.

Hepatic stellate cells (HSC), or Ito cells, store vitamin A when at rest but undergo phenotypic changes in situations of liver injury, which may induce fibrosis, and they may participate in the immune response in the liver. The objective of the present study was to investigate the role of HSC in the livers of dogs with visceral leishmaniasis (VL). Twenty-eight livers from dogs infected with VL that were living in an area endemic for the disease were evaluated, among which 13 were asymptomatic (A) and 15 were symptomatic (S). A control group (C) was formed by five dogs from an area that was not endemic for VL. These organs were subjected to histopathological analysis (Masson's trichrome for fibrosis) and immunohistochemical analysis (Leishmania, smooth-muscle α-actin and TGF-β). In the livers from the symptomatic dogs, a moderate to severe granulomatous inflammatory reaction was observed in the capsule and in the portal, centrilobular and intralobular regions. In the asymptomatic dogs, there was slight to moderate presence of granulomas, and these were even absent in some dogs. The intensity of hepatic fibrosis was predominantly low in the infected dogs (A and S), and fibrosis was absent in the control group. The immunomarking of HSC in the infected groups (A and S) differed significantly (P = 0.0153) from that of the control group. The symptomatic dogs presented the largest number of positive cells. This group also presented a larger number of parasitized macrophages, but did not differ statistically from the asymptomatic group (P > 0.05). The cytokine TGF-β was only detected at low levels, and only in the infected animals, but this did not differ from the control group. Immunomarking for HSC was observed mainly in the nuclei of cells present in the hepatic granulomas of symptomatic dogs and in the sinusoids of the asymptomatic dogs. It was concluded that in the livers of dogs with VL, the HSC are activated and participate in the hepatic response to the parasite. The cytokine TGF-β may be involved in this activation, but in the chronic phase of the infection, this cytokine was detected at lower proportions. It is possible that HSC may also contribute towards chemotaxis of leukocytes for the hepatic compartment, along with other cell types such as Kupffer cells.

Polymorphism, coupling interval and prematurity index in dogs with degenerative mitral valve disease and ventricular arrhythmias.

Ventricular arrhythmias (VA) are a recognized concern in dogs with degenerative mitral valve disease (DMVD). The coupling interval (CI) and the prematurity index (PI) have been shown to accurately differentiate between benign and malignant VA in people, where ventricular arrhythmias are known to be associated with an increased risk of development of signs of heart failure or sudden death. In this study, we characterized ventricular arrhythmias in dogs with symptomatic and asymptomatic DMVD. Seventy dogs with naturally-occurring DMVD and ventricular arrhythmias were retrospectively studied. A cross-sectional investigation including dogs with either symptomatic (stages C/D; n = 41) or asymptomatic (stages B1/B2; n = 29) DMVD was performed. Electrocardiographic tracings were reviewed to calculate both the CI and PI. In eight dogs these indices were compared with those obtained from both a Holter recording and a standard ECG tracing and no statistical differences were found (CI, p = 0.97; PI, p = 0.17). Even though CI and PI were determined in all animals enrolled in the study, VPC characteristics were only compared between symptomatic and asymptomatic dogs when a 24-h Holter recording was available (n = 49). The PI was different (p = 0.01) between symptomatic (0.65 ± 0.17) and asymptomatic (0.56 ± 0.18) dogs, but CI was considered similar (p = 0.91). Also, the symptomatic dogs had more polymorphic VPC (p = 0.002) and supraventricular arrhythmias (p = 0.0002) than the asymptomatic animals. Polymorphism, and repeating patterns of ventricular premature complexes, were characteristics frequently present in overtly symptomatic animals affected by mitral endocardiosis.

Left atrial deformation and phasic function determined by two-dimensional speckle-tracking echocardiography in dogs with myxomatous mitral valve disease

IntroductionLeft atrial (LA) function can provide useful information in dogs with myxomatous mitral valve disease (MMVD). Recently, we have demonstrated the feasibility of measuring LA longitudinal deformation using speckle-tracking echocardiography (STE) to estimate LA function in healthy dogs. Whether LA strain and strain rate variables provide additional information about LA function and clinical cardiac status in dogs with MMVD remains unexplored. AnimalsNinety-six client-owned dogs of different breeds with MMVD were prospectively enrolled. MethodsLA longitudinal deformation was evaluated in each dog by STE and different STE variables were used to assess LA function. ResultsNo STE variables differed between American College of Veterinary Internal Medicine Stage B1 and B2 dogs but were lower in Stage C dogs. Peak atrial longitudinal average strain < 27.9%, left-atrial-to-aortic ratio > 2.2 and peak atrial contraction average strain < 7.25% discriminated symptomatic MMVD dogs by receiver operating characteristic analysis with sensitivity and specificity of 100% and 100% (95% confidence interval [CI] 91–100%), 92% (95% CI 78–98%) and 98% (95% CI 87–100%), 100% (95% CI 91–100%) and 95% (95% CI 83–99%), respectively. In 12 dogs with similar left-atrial-to-aortic ratio, peak atrial longitudinal average strain and peak atrial contraction average strain differentiated dogs with subclinical disease from those with congestive heart failure (CHF). ConclusionDogs with MMVD in CHF appear to have lower LA longitudinal strain and strain rate variables compared with dogs with subclinical disease. Further studies are needed to establish if our initial findings can provide useful information for the diagnosis, treatment, and prognosis of dogs with MMVD.

Digital PCR Platform as a Tool to Determine the Canine Coronavirus (CCoV) Genome in Clinical Samples

Canine coronavirus (CCoV) is an important pathogen that affect dogs. Here we assessed a digital real-timebased PCR (dPCR) for the detection of CCoV from infected AF-72 cells and directly from faeces from 100 symptomatic dogs.

Digital PCR Platform as a Tool to Determine the Canine Coronavirus (CCoV) Genome in Clinical Samples

Canine coronavirus (CCoV) is an important pathogen that affect dogs. Here we assessed a digital real-timebased PCR (dPCR) for the detection of CCoV from infected AF-72 cells and directly from faeces from 100 symptomatic dogs.

Cellular apoptosis and nitric oxide production in PBMC and spleen from dogs with visceral leishmaniasis

Nitric oxide (NO) is involved in the death of the Leishmania parasite and regulation of apoptosis. We quantified the frequency of cells producing NO and its levels in the peripheral blood mononuclear cells (PBMC), leukocytes from spleen in Visceral Leishmaniasis (VL) symptomatic dogs and correlated NO levels with apoptosis and parasite load in the spleen. The percentage of NO+ cells and CD14+/NO+ was higher in PBMC and spleen cells in infected dogs than in controls. The levels of NO+ and CD14+/NO+ cells was higher in PBMC, but lower spleen of dogs infected than compared to control. Late apoptosis rates increased in PBMC and spleen of infected dogs compared to controls, and the NO levels and apoptosis not showed correlation. There was a positive correlation between the percentage of cells producing NO in the spleen and parasite load. The NO participates in the immune response in the canine VL, but it is not apoptosis inducer.

Factors associated with positivity for canine visceral leishmaniosis in an endemic area in Brazil.

Visceral leishmaniosis (VL) is a public health problem and its occurrence depends primarily on the presence of the vector and susceptible hosts; in the urban environment, the dog is the main reservoir. This study aimed to analyze the distribution of canine visceral leishmaniosis (CVL) and factors associated with it in an urban area endemic for VL. Analysis of the variables was based on 2755 epidemiological records of dogs positive and negative for CVL over a three-year period (2009, 2010 and 2011). A dog was considered positive when it presented amastigotes in the cytological examination of lymph node biopsy and/or was seropositive by immunoenzymatic and indirect immunofluorescence assays. CVL positive dogs were observed throughout the town, but significant differences were observed between the sectors analyzed (P<0.0001), with two sectors showing higher positivity. CVL prevalence was 35.9% and was significantly associated with age and breed (P<0.0001). Concerning symptoms, 44.3% of symptomatic dogs were positive for LV (P<0.0001) in an urban area endemic for this zoonosis.

Investigating and identifying Chlamydia psittaci in asymptomatic and symptomatic domestic dogs in middle province of Iran

Investigating and identifying Chlamydia psittaci in asymptomatic and symptomatic domestic dogs in middle province of Iran

Doxycycline treatment efficacy in dogs with naturally occurring Anaplasma phagocytophilum infection.

To evaluate doxycycline treatment efficacy and post-treatment pathogen persistence in dogs naturally infected with Anaplasma phagocytophilum in endemic regions of the USA. Symptomatic dogs in four US states (MN, WI, CT and CA) were evaluated before treatment with doxycycline and approximately 30 and 60 days post-treatment. Clinicopathological parameters, co-exposures and A. phagocytophilum DNA in whole blood and lymph node samples were compared between A. phagocytophilum infected and uninfected dogs. In total, 42 dogs fulfilled the inclusion criteria, with 16 dogs (38%) blood PCR-positive and 26 dogs (62%) blood PCR-negative for A. phagocytophilum. At initial evaluation, the proportion of clinicopathological abnormalities was similar between A. phagocytophilum infected and uninfected dogs, although thrombocytopenia and lymphopenia were statistically more prevalent among A. phagocytophilum infected dogs. Treatment with doxycycline resulted in resolution of all clinical abnormalities in infected dogs; four dogs had persistent haematological abnormalities, including mild leukopenia, eosinopenia and lymphopenia. All 16 infected dogs became blood PCR-negative approximately 30 and 60 days after treatment onset. Additionally, 13/13 (100%) lymph node specimens tested post-treatment were PCR-negative. Select clinicopathological abnormalities persisted in uninfected dogs after treatment. The results of this study support the efficacy of doxycycline therapy for clinical treatment of dogs naturally infected with A. phagocytophilum in the USA. This study did not find clinical, haematological or microbiological indicators that supported the persistence of A. phagocytophilum infection in naturally infected dogs following treatment with doxycycline for 28 days.