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Background: In recent years, the usefulness of echocardiography and serum biomarkers in the diagnosis of pulmonary hypertension (PH) in dogs with heartworm disease has been studied. Previously, N-terminal pro B-type natriuretic peptide (NT-proBNP) has shown high concentrations in dogs with heart disease and/or PH as well as its usefulness as a prognostic indicator, but it has never been evaluated in the diagnosis and prognosis of PH in dogs with heartworm disease. The aim was to evaluate the serum concentrations of NT-proBNP in dogs infected by Dirofilaria immitis to determine its usefulness as a tool to detect precapillary PH., Methods: NT-proBNP was determined in 50 heartworm-infected dogs. Presence/absence of PH was determined echocardiographically, using the Right Pulmonary Artery Distensibility Index (RPAD Index) and the systolic flow of tricuspid regurgitation mainly, together with other echocardiographic measurements following the guidelines of the American College of Veterinary Internal Medicine (ACVIM) for the diagnosis of PH. Other epidemiological parameters (breed, age, sex, status: client-owned or shelter dogs) and clinical parameters (microfilaremia, parasite burden, presence of symptoms, body condition) were collected as well., Results: Moderate-severe PH was present in 40% of the dogs (RPAD Index < 29.5%), NT-proBNP concentrations being significantly higher compared with dogs that did not have PH. A cutoff for NT-proBNP of ≥ 1178.45 pmol/l showed a sensitivity of 64.3% and a specificity of 95.5% for the presence of moderate-severe PH. Older dogs and dogs from shelters showed significantly higher NT-proBNP concentrations. Dogs with symptoms and low body condition presented significantly higher NT-proBNP concentrations as well., Conclusions: The determination of NT-pro-BNP concentration can be a useful tool in the diagnostic work-up of dogs with heartworm disease and associated PH and can help to identify animals in the more advanced stage of this disorder., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Background: Cats can be infected by Dirofilaria immitis, the causative agent of heartworm disease, characterized by respiratory signs, airway hyperreactivity, remodelling and inflammation. Allergy is a multifactorial pathology, and the role of a number of helminth parasites in the development of allergies in humans and other species has been demonstrated in many studies. The aim of the present study was to verify whether cats seropositive for D. immitis present hypersensitivity to some environmental allergens., Methods: Blood samples were collected from 120 cats and tested for the presence of specific immunoglobulin G antibodies against D. immitis and for hypersensitivity to 20 allergens, using commercial allergen test kits., Results: Of the 120 cats tested, 72 (60.0%) were seropositive for anti-D. immitis IgG and 55 (45.8%) showed clinical signs of heartworm disease of a respiratory nature. The results of testing with the allergen kits showed that 50.8% of cats were seropositive for ≥ 1 allergens, with the most common allergens being Dermatophagoides farinae (25.8%), Dermatophagoides pteronyssinus (20.0%), Malassezia (17.5%) and Ctenocephalides felis (14.2%). The prevalence of allergies was significantly higher-by almost threefold-in cats seropositive for D. immitis (68.1% vs. 25%). There were no significant differences between the prevalence of allergic cats and presence/absence of symptoms, and the results confirmed that symptoms were not a decisive factor for the presence of allergies. The risk for developing allergies was 6.3-fold higher in cats seropositive for D. immitis than in cats that were seronegative, confirming that seropositivity for D. immitis is a risk factor., Conclusions: Cats with confirmed heartworm can develop serious respiratory signs, potentially leading to progression to permanent lung injury and predisposing cats to hyperresponsive airway disease. Previous studies have shown that seropositivity for D. immitis and Wolbachia is related to the presence of bronchoconstriction and bronchospasm in the affected cat. The results support the suspicion that contact with D. immitis may be a risk factor for the presence of allergies., (© 2023. The Author(s).)

Simple Summary: Heartworm disease is a zoonotic illness primarily affecting dogs and cats, which poses a significant risk to public health. Gran Canaria (Canary Island, Spain) serves as a hyperendemic region for this disease, offering a model for its study. This research aimed to track Dirofilariosis prevalence and distribution among dogs, cats, and residents from 1994 to 2020. Data from 5841 dogs, 1203 cats, and 1604 humans were analyzed, considering geographical and climatic factors. Results revealed a decline in Dirofilaria immitis prevalence over the years: from 67.02% in dogs (1994) to 15.81% (2020), and from 33.03% (2010) to 17.20% (2020) in cats. Human incidence dropped from 18.66% (2008) to 8.27% (2020). Prevalence was highest in temperate cold zone (TC) and temperate mild zone (TM) climates. Despite a decrease in prevalence, Gran Canaria remains hyperendemic. The study underscores the significance of a "One Health" approach and highlights ongoing risks of disease transmission. Dirofilariosis is a zoonotic disease that mainly affects dogs and cats, with a high risk to public health. The island of Gran Canaria (Spain) has been shown to be a hyperendemic area of infection and, therefore, a model for studying the evolution of the disease. The objective of this study was to track the prevalence and distribution of heartworm in dogs, cats, and residents of Gran Canaria from 1994 to 2020, using published and unpublished data. Blood samples from 5841 dogs, 1203 cats, and 1604 humans were collected in the years analyzed, considering geographical and isoclimatic factors. In 1994, a prevalence of Dirofilaria immitis of 67.02% in dogs was reported, while in 2020 it was 15.81%. In cats, the seroprevalence in 2010 was 33.03%, compared to 17.20% in 2020. The incidence of D. immitis in humans in 2008 was 18.66%, while in 2020 it was 8.27%. For all study groups, temperate cold zone (TC) and temperate mild zone (TM) climates had the highest prevalence. Throughout these 20 years, the prevalence of heartworm disease has decreased. Despite this, it continues to be a hyperendemic island. This study highlights the importance of using the "One Health" perspective and the risks of contagion of the disease. [ABSTRACT FROM AUTHOR]

Simple Summary: The development of new echocardiographic techniques, such as two-dimensional speckle tracking echocardiography and assessment of longitudinal myocardial deformation, may be new alternative tools to analyse the presence and severity of pulmonary hypertension in heartworm disease. A total of 93 dogs were used, of which 71% were diagnosed with heartworm infection and 41% were found to have PH. The measurements evaluated were obtained using Right Ventricular Automated Function Imaging (RV AFI®) software. The results showed significant differences between animals with and without pulmonary hypertension. Cut-off values with high sensitivity and specificity were also obtained for the detection of pulmonary hypertension in the animals analysed. Echocardiographic measurements for functional assessment of the right ventricle using myocardial longitudinal strain have demonstrated their usefulness in heartworm-infected dogs. Echocardiographic assessment of the right ventricle is helpful for analysing the pathophysiology of heartworm disease and detecting pulmonary hypertension (PH) in dogs. In veterinary cardiology, the study of myocardial deformation using two-dimensional speckle tracking (2D-STE) echocardiography has become increasingly acknowledged as useful for quantifying right ventricular function. The aim of this study was to evaluate the usefulness of myocardial deformation strain of the right ventricular free wall (FWS), global deformation strain of the right ventricle, including the interventricular septum (GS), and tissue motion annular displacement of the tricuspid valve (TMAD) in a cohort of dogs with heartworm (Dirofilaria immitis) disease and to determine cut-off values for detecting the presence of PH. Out of the 93 dogs tested, 71% were diagnosed with heartworm infection. PH was identified in 41% of the infected dogs following the American College of Veterinary Internal Medicine (ACVIM) guidelines, based on the peak tricuspid regurgitation velocity to calculate the tricuspid regurgitation pressure gradient (TRPG), while other routine measurements were used, including the right pulmonary artery distensibility index (RPADi). The 2D-STE mode measurements were determined using Right Ventricular Automated Function Imaging (RV AFI®) software. The statistical analysis showed significant differences in the studied parameters among dogs with and without PH. Additionally, sensitivity (sen) and specificity (sp) cut-off values were obtained (GS ≥ −21.25%, sen 96%, sp 86.4%; FWS ≥ −21.95%, sen 92.56%, sp 95.5%; TMAD ≤ 0.85 cm, sen 70.4%, sp 83.3%). These results demonstrated that GS, FWS, and TMAD could be used as supplementary and alternative variables to conventional echocardiographic measurements when detecting PH in dogs with heartworm disease. [ABSTRACT FROM AUTHOR]

Simple Summary: Tissue Doppler imaging is a useful echocardiographic technique to evaluate the systolic and diastolic function of the right ventricle and has been used as an estimator of pulmonary hypertension. The objective of this study was to evaluate the diagnostic value of tissue Doppler echocardiography to determine the presence of pulmonary hypertension in dogs with heartworm disease. A total of 116 heartworm-infected dogs and 33 healthy dogs were included in the study. Echocardiographic determinations were performed following established protocols to determine the presence of pulmonary hypertension in 47.4% of dogs infected with heartworm. Subsequently, a total of eight echocardiographic measurements were performed using tissue Doppler imaging to determine their usefulness in the diagnosis of pulmonary hypertension. Overall, the results showed significant differences with respect to the presence or absence of pulmonary hypertension. Furthermore, acceptable cut-off values were reported to estimate the presence of pulmonary hypertension in most echocardiographic measurements determined using tissue Doppler imaging. The measures analysed have demonstrated their usefulness as a complementary tool to determine pulmonary hypertension in dogs with Dirofilaria immitis. Background: Dirofilaria immitis is a nematode that produces proliferative pulmonary endarteritis in dogs due to direct contact of the adult parasites with the intima layer of the pulmonary arteries, leading to irreversible severe structural damage and sustained pulmonary hypertension (PH), which can produce severe cardiorespiratory disorders. The purpose of this study was to assess the diagnostic value of the echocardiography tissue Doppler imaging (TDI) in determining the presence of PH in dogs with heartworm disease. Methods: There were 116 heartworm-infected dogs with PH and 33 healthy dogs included in the study. Based on the right pulmonary artery distensibility index (RPADi) < 29.5%, PH was present in 47.4% of infected dogs. Additionally, the animals were evaluated using other standard alternative echocardiographic measures to estimate PH. Moreover, a total of eight echocardiographic measurements were analysed using the TDI to determine its usefulness in diagnosing PH (E′, A′, S, E′:A′, global TDI, HRI-IVCT, HRI-IVRT, R-TEI). Results: The TDI measurements showed significant differences between dogs with and without PH, demonstrating a positive correlation with respect to the RPADi. In addition, cut-off values for the detection of PH with excellent sensitivity and specificity were found for E′:A′, global TDI, HRI-IVCT, HRI-IVRT and R-TEI. Conclusions: The TDI mode may be useful as an adjunct diagnostic method for the determination of PH in dogs with Dirofilaria immitis. [ABSTRACT FROM AUTHOR]

Simple Summary: Pulmonary hypertension (PH) is a phenomenon frequently seen in dogs with heartworms. Given the seriousness of this condition, numerous studies have focused on determining its presence. In this study, the pulmonary vein to pulmonary artery ratio (PV:PA ratio), determined by echocardiography, is evaluated in 151 dogs to determine its usefulness in the detection of PH in heartworm. The results showed that the PV:PA ratio could be useful as a complementary diagnostic method to estimate the presence of moderate or severe PH in these patients. Background:Dirofilaria immitis produces proliferative pulmonary endarteritis and pulmonary thromboembolism in infected dogs. The pulmonary vascular lesions lead to irreversible and persistent structural damage and, as a consequence, sustained precapillary pulmonary hypertension (PH). The purpose of this study was to assess the diagnostic value of the pulmonary vein to pulmonary artery ratio (PV:PA ratio) to determine moderate or severe PH (>50 mmHg) in dogs with heartworm disease. Methods: A total of 151 naturally heartworm-infected and 66 healthy dogs were included in the study. The presence/absence of PH was based on the right pulmonary artery distensibility index (RPAD index < 29.5%), and the PV:PA ratio was echocardiographically measured by the time–motion mode (M mode) and two-dimensional mode (2D mode). Other echocardiographic parameters were also assessed (pulmonary trunk to aorta ratio, tricuspid regurgitation pressure gradient, and AT:ET ratio). Results: The results of the PV:PA ratio showed a highly positive correlation between the M and 2D modes (r = 0.928). The PV:PA ratio obtained by the M mode was identified as the strongest predictor for RPAD index (R2 0.628, p < 0.0001) with a good diagnostic accuracy (AUC = 0.99). The results of PV/PA by the 2D mode showed a similar prediction for the RPAD index (R2 0.606, p < 0.0001) with a good diagnostic accuracy (AUC = 0.98). Both of the 2D and M modes' PV:PA ratios decreased significantly with the presence of PH. A cut-off value of ≤0.845 showed high sensitivity and specificity for the M mode (97% and 94%, respectively) and the 2D mode (96% and 93%, respectively). Conclusions: The PV:PA ratio may be useful as a complementary diagnostic method for the estimation of moderate or severe PH in dogs with heartworm. [ABSTRACT FROM AUTHOR]

Simple Summary: Pulmonary hypertension (PH) is a consequence of proliferative pulmonary endoarteritis caused by the parasite Dirofilaria immitis (heartworm). To date, the diagnosis is carried out through echocardiographic determinations, with the right pulmonary artery distensibility (RPAD) index being the gold standard for diagnosis of PH caused by heartworm. Given the high importance and frequency of PH in dogs, the study of the pulmonary trunk to aorta ratio (PT:Ao) determined by computed tomography (CT) was proposed to assess its usefulness in the diagnosis of PH, compared to the gold standard method. The results show that the PT:Ao ratio was reliable for detecting and staging the severity of moderate to severe PH in dogs with heartworm. Dirofilaria immitis causes proliferative pulmonary endoarteritis that leads to the appearance of chronic precapillary pulmonary hypertension (PH) in dogs. Pulmonary trunk to aorta ratio (PT:Ao ratio) obtained by computed tomography (CT) was studied and the quantitative measure of the diameters of the pulmonary trunk (PT), the descending thoracic aorta (DAo) and ascending thoracic aorta (AAo) were evaluated for the determination of the presence of moderate to severe PH in 59 dogs. The diagnosis of PH was echocardiographically determined, based on the determination of the right pulmonary artery distensibility (RPAD) index (<29.5%), and compared with other parameters for estimating PH. The results showed a very high concordance: 0.976 (p-value 0.000) between the two CT methods (PT:DAo and PT:AAo) with an excellent intraclass correlation coefficient > 0.95. Moreover, cut-off values of ≥1.111 for PT:DAo, and ≥1.057 for PT:AAo were determined for dogs with an RPAD index < 29.5%, which suggests a cut-off value between healthy dogs and the presence of PH. As has been previously published, The PT:Ao ratios did not determine the presence of mild PH, so the measurements cannot be considered useful for the early diagnosis of PH in dogs with heartworm. [ABSTRACT FROM AUTHOR]

Simple Summary: Dirofilaria immitis is a nematode parasite causing heartworm disease worldwide. Spain is one of the southern European countries where the risk of infection in domestic dogs is moderate/high. The aim of this study was to update the epidemiology of canine heartworm and analyse the results based on climate and other geo-environmental factors. For this, 9543 blood samples from dogs from all provinces, autonomous cities and islands that comprise Spain were tested using D. immitis antigen tests. The mean prevalence obtained was 6.47%. Prevalences exceeding 11% were located in the northwestern and southern provinces, in the Balearic and Canary Islands. The presence of positive dogs was described for the first time in provinces and islands where previously no cases of infected dogs had been reported. Considering its zoonotic character, further studies are needed to identify infected animals and to carry out national control programmes for the prevention of heartworm disease. The climate of Spain has favourable characteristics for the development of D. immitis in dogs, being an endemic country. Given that vector-borne diseases are spreading rapidly through Europe, due to factors such as climate change, the expansion of vectors and the increased mobility of reservoir animals, the aim was to update the epidemiology of heartworm in dogs and analyse the results based on climate and other epidemiological and geo-environmental factors. To this aim, 9543 blood samples from dogs from all provinces and autonomous cities of Spain were analysed for the detection of antigens of D. immitis, obtaining a prevalence of 6.47%. The northwestern and southern provinces showed the highest prevalences, as well as in the Balearic and Canary Islands. Prevalences were higher in dogs outdoors. Furthermore, most of the positive dogs were found in regions with high humidity and water availability. This study shows, for the first time, positive cases in provinces and islands where no cases had previously been described and demonstrates the continuous expansion and consolidation of heartworm in Spain. Considering its zoonotic character, the implementation of control and awareness programmes for the prevention of D. immitis in pets is necessary. [ABSTRACT FROM AUTHOR]