Search Results (107)

Background and Clinical Significance: Animal hoarding is a recognized form of animal cruelty characterized by the accumulation of animals under conditions of inadequate care, leading to compromised welfare and an increased risk of disease transmission. Veterinarians are often the first to identify such cases through clinical presentation. This case report describes a forensic investigation of a dog associated with animal hoarding and environmental neglect in Bangkok, Thailand. Case Presentation: A 7-year-old male mixed-breed dog was presented with seizures, emaciation, dehydration, and ectoparasite infestation. Hematological findings revealed leukopenia and anemia, and diagnostic testing confirmed infection with canine distemper virus (CDV) and Dirofilaria immitis. Despite supportive treatment, the dog died within 48 h. A subsequent site inspection, conducted using the TRACE model and based on crime scene investigation principles, identified 13 dogs housed in overcrowded and unsanitary conditions. Environmental assessment revealed poor sanitation, waste accumulation, and fluorescent stains of unknown origin detected under ultraviolet light (365 nm) in the cage areas. Among the animals, infections with CDV (23.08%), Dirofilaria immitis (53.85%), and Ehrlichia canis (61.54%) were identified, indicating a high burden of infectious and vector-borne diseases. Conclusions: This case demonstrates the value of integrating clinical veterinary findings with forensic investigation in the assessment of animal neglect. The combined use of clinical, laboratory, and environmental evidence strengthens documentation and supports potential legal action. Enhanced veterinary forensic training and standardized protocols are recommended to improve early detection and intervention in animal cruelty cases. Full article

Canine dirofilariasis, caused by Dirofilaria immitis and Dirofilaria repens, is an emerging vector-borne disease of increasing veterinary and zoonotic importance. Rapid and species-specific detection is essential for effective clinical management and epidemiological surveillance. This study aimed to develop and diagnostically evaluate two novel species-specific loop-mediated isothermal amplification (LAMP) assays for the direct detection of D. immitis and D. repens in canine whole blood, performed in parallel in separate reactions, with emphasis on simplified and potentially near-point-of-care applicability. Primers targeting mitochondrial COI and NADH gene regions were designed and validated. In silico specificity analysis against 13 filarioid species confirmed the absence of non-specific primer binding. A direct closed-tube LAMP protocol using sodium hydroxide–Chelex-100 lysis was optimized, enabling amplification without conventional DNA extraction while reducing contamination risk and processing time to under 60 min. Relative diagnostic performance was evaluated relative to quantitative real-time PCR (qPCR) results. Using purified DNA, the D. repens assay achieved 100% relative sensitivity and relative specificity, whereas the D. immitis assay showed 94.5% relative sensitivity and 100% specificity. In direct whole-blood assays, relative specificity remained 100% for both targets, while sensitivity decreased to 90.9% for D. immitis and 77.42% for D. repens, with most false-negative reactions associated with high qPCR Ct values (>30). These findings demonstrate that the proposed assays provide a rapid and practical molecular diagnostic approach with potential applicability for point-of-care veterinary testing. Full article

Heartworm-Associated Respiratory Disease (HARD) is an early manifestation of feline dirofilariosis caused by immature Dirofilaria immitis stages reaching the lungs and inducing marked inflammatory airway lesions. This study quantified computed tomography (CT)-derived bronchial wall remodeling in cats with clinical and serological features compatible with HARD using the bronchial wall-to-bronchus (BW/B) and bronchial wall-to-pulmonary artery (BW/A) ratios. Twenty-seven client-owned cats were prospectively included: 19 cats with lower-airway clinical signs and D. immitis antibody seropositivity, considered compatible with HARD, and 8 asymptomatic seronegative cats that underwent CT for non-cardiorespiratory clinical indications. All underwent thoracic CT under a standardized anesthetic protocol. Bronchial lumen diameter, total bronchial diameter, and pulmonary artery diameter were measured in cranial and caudal lung regions, and bronchial wall thickness was calculated to derive BW/B and BW/A. Cats compatible with HARD showed significantly increased bronchial wall thickness and higher BW/B and BW/A ratios across all evaluated lung lobes, supporting diffuse bronchial remodeling. BW/A was the only index showing a significant area-by-group interaction, suggesting a possible regional distribution pattern of bronchial wall remodeling in affected cats. Measurement repeatability and reproducibility were high overall. CT-derived bronchial wall indices, particularly BW/A, may provide an objective complementary tool for characterizing airway involvement in cats with clinical and serological profiles compatible with HARD. Because antibody seropositivity indicates exposure rather than confirmed active infection, and because of the small control group, absence of respiratory disease comparators, and lack of histopathological validation, these findings should be considered preliminary and descriptive. Full article

Dirofilaria immitis constitutes a significant global veterinary burden and an emerging zoonotic risk. Despite decades of study, the structural evolution of its scientific landscape remains unexplored. This study provides a comprehensive longitudinal analysis of global research on D. immitis to evaluate its trajectory, intellectual structure, and conceptual shifts over the last eight decades. A systematic bibliometric analysis was conducted following PRISMA guidelines adapted for bibliometrics. Data were retrieved from Web of Science Core Collection and Scopus, covering the period from 1945 to 2025. After deduplication and manual screening, a final corpus of 3589 documents was analyzed using performance indicators and science mapping techniques to assess growth patterns, geographic leadership, collaboration networks, and thematic evolution. The field exhibits a mature profile with a sustained mean annual growth rate of 2.39%. Production is geographically polarized, with the United States and Italy acting as the primary research hubs, though international collaboration networks are increasingly integrating endemic regions in the Global South. Thematic analysis reveals a profound paradigm shift: while early research (1945–1980) focused on parasite morphology and clinical description, the 21st century is characterized by a multidisciplinary approach dominated by molecular biology, the study of the endosymbiont Wolbachia, and the genetic mechanisms of macrocyclic lactone resistance. The intellectual structure is currently organized into distinct but interconnected clusters, linking established clinical pathology with emerging genomic and environmental control strategies. Research on D. immitis has evolved from a classical parasitology discipline into a complex biomedical ecosystem aligned with the One Health framework. The persistence of the disease, driven by drug resistance and climate-mediated vector expansion, has catalyzed a transition toward integrative research models. Future control strategies must transcend geographic borders, combining advanced genomic surveillance with ecological modeling to mitigate the impact of this transboundary disease on both animal and human health. Full article

Background/Objectives/Methods: A bioassay-informed investigation of the Australian pasture soil-derived Streptomyces sp. S4S-00193A39 yielded the anthelmintic principals as three new spiroketal polyketide alkaloids, goondoxazoles A–C (1–3), with structures assigned by detailed spectroscopic analysis. Results: A structure–activity relationship based on the ability to inhibit the motility of Dirofilaria immitis microfilariae (mf) revealed a positive correlation for the benzoxazole moiety present in 2 and 3 (EC₅₀ 55–85 nM) versus the ring-opened aminobenzoic acid moiety evident in 1 (EC₅₀ 1.38 µM). This hypothesis was strengthened by extension of the SAR assessment to the known benzoxazole natural products A-33583 (12), UK-1 (13) and nataxazole (14), and the new analogue 5-hydroxynataxazole (15), which were isolated in our lab from three additional Australian pasture soil-derived Streptomyces spp. Of note, while the benzoxazole methyl esters 13–15 exhibited approximately 9- to 65-fold lower potency against D. immitis mf compared with 2 and 3, the carboxylic acid substituted benzoxazole 12 displayed comparable activity (EC₅₀ 72 nM) against D. immitis mf, and >5-fold improved potency against D. immitis L4 larvae (EC₅₀ 0.43 µM). Conclusions: These observations reveal the promising anthelmintic potential (against D. immitis) for the new structurally complex and chiral goondoxazoles (e.g., 2 and 3), and demonstrate that this effect can be replicated, even improved, by simpler, achiral benzoxazole microbial natural products (e.g., 12). Full article

Feline heartworm disease, caused by Dirofilaria immitis, is often underdiagnosed, particularly during its larval stage, known as Heartworm-Associated Respiratory Disease, (HARD). This study aimed to quantify CT-detectable pulmonary changes in naturally infected cats. Computed tomography (CT) was performed in 38 cats: Group A (n = 30, symptomatic seropositive) and Group B (n = 8, asymptomatic seronegative). Bronchial and pulmonary artery diameters were indexed to the sixth thoracic vertebral body (T6) to calculate bronchial-to-vertebral body (B/VB) and pulmonary artery-to-vertebral body (A/VB) ratios across all lung lobes. Group A cats showed significantly higher B/VB ratios in the left cranial and right middle lobes compared with Group B (p < 0.05), with increases of 42.0% and 47.5%, respectively. Conversely, A/VB ratios did not differ significantly between groups (p > 0.05), indicating the absence of relevant vascular remodelling. Intra-operator and inter-observer reliability were excellent (intraclass correlation coefficients > 0.85). These findings suggest that bronchial dilation in the absence of arterial enlargement represents a key tomographic feature of larval D. immitis infection. Quantitative CT ratios, particularly the B/VB ratio, provide objective imaging markers for the diagnosis of HARD in clinical practice, and may assist in differentiating this condition from other feline respiratory diseases in endemic areas. Full article

Understanding the determinants of host specificity in Dirofilaria immitis can be advanced through the use of the nonpermissive Mongolian gerbil (jird) model. We hypothesized that host immunity dictates D. immitis establishment following the third larval molt. Jirds were infected intraperitoneally with 100 Brugia malayi (permissive control) or D. immitis third-stage larvae (L3). Necropsies occurred at 1, 3, 10, and 36 days post infection (dpi) to quantify larvae via peritoneal lavage. Initial recovery at 1 dpi showed 37.4% for B. malayi but only 0.4% for D. immitis (p < 0.0001). Dirofilaria immitis recovery increased to 23.6% by 3 dpi, suggesting a period of transient tissue residence during the third molt. Recovery for both species decreased by 10 dpi. Brugia malayi reached the immature adult stage (15.2%) by 36 dpi, whereas no viable D. immitis were recovered (p < 0.0001). These findings suggest that D. immitis larvae encounter a robust cellular response, primarily macrophages, shortly after the third molt. Identifying the specific larval stage at which establishment fails provides critical insight into the mechanisms governing filarial host specificity. Full article

Canine vector-borne diseases (CVBDs) are caused by pathogens transmitted by several invertebrates, posing a significant threat to both animal and human health worldwide. In recent years, the geographical distribution of CVBDs has changed in many countries, driven by climate change, increased pet travel, movements of goods, and anthropization of wildlife habitats. This study investigated the exposure to major CVBDs in 423 owned dogs from Italy and Greece. Individual serum samples were analyzed using serological methods. The SNAP^® 4Dx IDEXX test was used to detect Dirofilaria immitis circulating antigens and antibodies against Anaplasma spp., Ehrlichia spp. and Borrelia burgdorferi. Additionally, an indirect immunofluorescence antibody test (IFAT) was used to detect antibodies against Rickettsia conorii and Babesia canis. Overall, 171 (40.4%) dogs were positive for at least one pathogen. Antibodies against R. conorii, Ehrlichia spp., Anaplasma spp., B. canis and B. burgdorferi were detected in 118 (27.9%), 28 (6.6%), 29 (6.8%), 5 (1.2%) and 3 (0.7%) dogs, respectively. Dirofilaria immitis antigens were found in 7 dogs (1.6%). A Binomial Logistic Regression was performed and revealed a statistically significant association between age (dogs > 7 years old) (p = 0.005; OR = 1.903; 95% CI = 1.215–2.2981) and presence of at least one clinical sign (p = 0.028; OR = 4.082; 95% CI = 1.168–14.262) and positivity to at least one vector-borne pathogen. These findings confirm that dogs in both Italy and Greece are exposed to a range of vector-borne pathogens and highlight the importance of continuous epidemiological surveillance in European regions. Full article

Pulmonary vascular proliferative lesions are rarely reported and poorly characterized in animals. In this study, we describe 13 cases identified in wild Korean raccoon dogs (Nyctereutes procyonoides), suggesting a higher-than-expected incidence in this species. Gross examination revealed villous projections within the lumina of pulmonary vessels, sometimes accompanied by pneumonia, hemorrhage, or Dirofilaria immitis (heartworm) infection. Most affected animals also presented with thick, dark gray cutaneous crusts associated with scabies infestation. Histopathologically, the lesions consisted of papillary proliferations within thickened vascular lumens. Special stains (Masson’s trichrome and Elastic Verhoeff–Van Gieson) demonstrated a single layer of endothelial cells lining fibromuscular and collagenous thick cores. Immunohistochemistry confirmed endothelial origin and benign proliferative nature, with positive expression of CD31, collagen types I, III, and IV, and proliferating cell nuclear antigen (PCNA). To date, pulmonary vascular proliferative lesions have not been well documented in N. procyonoides, and baseline pathological data, including findings from special stains, are lacking. These findings indicate that pulmonary vascular proliferative lesions may be underrecognized in raccoon dogs and suggest a likely association with chronic vascular injury related to parasitic infections. Further studies are warranted to elucidate the underlying mechanisms and contributing factors. Full article

Feline heartworm disease (Dirofilaria immitis) often leads to early pulmonary lesions even in infections by immature stages. Diagnosis is challenging due to nonspecific signs and limited sensitivity of serological tests, particularly in immature infections. To evaluate the relationships between the bronchial lumen and the pulmonary vasculature, 38 cats were evaluated thought computed tomography (CT). Of them, 30 were seropositive for D. immitis antibodies with respiratory signs and 8 seronegative controls. Thoracic CT scans were performed, and bronchial and vascular structures were measured. Ratios analyzed included bronchus-to-artery (BA), bronchus-to-vein (BV), and pulmonary vein-to-artery (PV/PA) ratios. Statistical comparisons were conducted across groups and lung lobes. Median BA and BV ratios were significantly higher in seropositive cats across most lung lobes. PV/PA ratios did not differ significantly between groups. Differences across lobes were significant in infected cats for BA and BV ratios. These findings indicate early bronchial remodeling in naturally infected cats, whereas pulmonary arteries and veins were less affected at this stage. Thus, BA and BV ratios are sensitive indicators of early pulmonary involvement and may improve diagnostic accuracy when used alongside conventional serological and imaging tests, which could support early identification and management of feline heartworm disease in endemic regions. Full article

Cardiovascular diseases in dogs have diverse causes and may progress rapidly to life-threatening complications. This review outlines the relevant pathological conditions involving the cardiovascular system in dogs, especially the myocardium, including myocarditis caused by canine parvovirus (CPV-2), heartworm disease (Dirofilaria immitis), hemangiosarcoma, and polyarteritis nodosa (PAN). CPV-2 affects the myocardium of puppies during the early weeks of life, leading to necrosis, fibrosis, and congestive heart failure. Heartworm disease is caused by adult D. immitis residing mainly in the pulmonary arteries, inducing pulmonary hypertension, right ventricular overload, and vascular damage, with the severity being related to the worm burden and duration of infestation. Hemangiosarcoma is a malignant vascular tumor, most frequently originating in the spleen or right atrium, often diagnosed at an advanced stage, with widespread metastases. Polyarteritis nodosa in dogs is a necrotizing, systemic vasculitis of medium-sized arteries that may affect the coronary arteries of the heart. Its pathogenesis is still unclear, though an immune-mediated mechanism is suspected. By presenting these lesions, the review underscores the many factors that can trigger cardiovascular diseases in dogs, as well as the clinical significance and the need for further research into their pathogenesis and treatment. Full article

Heartworm disease, caused by Dirofilaria immitis and transmitted by mosquitoes, represents a major veterinary and zoonotic concern. Beyond its recognized cardiopulmonary effects in dogs, increasing evidence suggests that parasite-derived antigens may contribute to allergic disease in humans. Gran Canaria (Canary Islands, Spain) is a hyperendemic region for heartworm disease, offering a unique setting to explore this potential relationship. Therefore, the aim was to analyze the association between canine infection with D. immitis and the occurrence of allergic conditions in their owners on Gran Canaria. This cross-sectional study included 644 dogs and their respective owners. Dogs were tested for circulating D. immitis antigens using a commercial rapid test. Owners provided information on allergy through medical anamnesis. Associations between canine infection status, animal-related variables (age, sex, breed, habitat), and owner-reported allergies (age, sex) were analyzed using chi-square and Fisher’s exact tests with Bonferroni correction. The results showed that 46.4% of dogs tested positive for D. immitis and 43.8% of owners reported allergic diseases. However, 24.64% of dog owners who tested negative for heartworm disease and 65.89% of owners with positive pets reported allergic diseases. In fact, owners of infected dogs exhibited a significantly higher prevalence of allergies compared to those of uninfected dogs. Canine age, sex, breed, and owner demographics were not associated with infection or allergies. However, dog habitat was significantly associated with both outcomes: dogs living indoors had lower infection rates, while owners of infected dogs in mixed indoor–outdoor environments reported the highest rates of allergy. This study provides the first epidemiological evidence of an association between canine heartworm infection and allergies in owners within a hyperendemic European region. The findings suggest that cohabitation with infected dogs may represent a novel risk factor for atopy, reinforcing the importance of integrated preventive measures and highlighting the relevance of a One Health approach. Full article

Dirofilariosis, a parasitic disease caused by nematodes of the genus Dirofilaria, primarily affects dogs but can also infect other carnivores and, more rarely, humans. In Europe, the most commonly involved species are D. immitis and D. repens, transmitted through the bites of mosquito vectors. This study, conducted in Tulcea County between April and October 2024, aimed to determine the prevalence of D. immitis and D. repens in mosquitoes. A total of 1507 mosquitoes were collected and grouped into 76 pools, and subsequently molecular analysis was carried out using qPCR. The estimated infection rate (EIR) was calculated using statistical methods available in the ‘binGroup’ package in R, which allow the determination of the point estimate and confidence interval (CI) for a single binomial proportion in group testing. The study revealed a high infection rate with D. immitis (48%), while D. repens was identified in only two pools. The species with the highest vector potential was Anopheles maculipennis (PTP = 75%, EIR = 0.1168 with both Dirofilaria species), followed by Aedes vexans. Notably, Aedes albopictus was identified for the first time in Tulcea, and all individuals were positive for D. immitis. Simulations of local thermal conditions using the proposed model show that the favorable time window for mosquitoes will increase until 2100. Our results indicate an established and active transmission cycle of D. immitis in the region, a situation projected to intensify with climate change requiring urgent monitoring. Full article

The filarioid nematode Dirofilaria immitis is the causative agent of heartworm disease, a major parasitic infection of canids, felids and occasionally humans. Current prevention relies on macrocyclic lactone-based chemoprophylaxis, but the emergence of drug resistance highlights the need for new intervention strategies. Here, we applied a machine learning (ML)-based framework to predict and prioritise essential genes in D. immitis in silico, using genomic, transcriptomic and functional datasets from the model organisms Caenorhabditis elegans and Drosophila melanogaster. With a curated set of 26 predictive features, we trained and evaluated multiple ML models and, using a defined threshold, we predicted 406 ‘high-priority’ essential genes. These genes showed strong transcriptional activity across developmental stages and were inferred to be enriched in pathways related to ribosome biogenesis, translation, RNA processing and signalling, underscoring their potential as anthelmintic targets. Transcriptomic analyses suggested that these genes are associated with key reproductive and neural tissues, while chromosomal mapping revealed a relatively even genomic distribution, in contrast to patterns observed in C. elegans and Dr. melanogaster. In addition, initial evidence suggested structural variation in the X chromosome compared with a recently published D. immitis assembly, indicating the importance of integrating long-read sequencing with high-throughput chromosome conformation capture (Hi-C) mapping. Overall, this study reinforces the potential of ML-guided approaches for essential gene discovery in parasitic nematodes and provides a foundation for downstream validation and therapeutic target development. Full article

Wild animals often serve as reservoirs for vector-borne zoonoses, which are on the rise worldwide but have not yet been sufficiently researched. Vector-borne zoonoses, such as those caused by Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato, and Dirofilaria immitis, are a growing public health concern due to their increasing incidence and broad host range. The aim of this study was to determine the prevalence and risk factors for vector-borne bacterial (borreliosis, anaplasmosis, ehrlichiosis) and parasitic (dirofilariasis) pathogens and to detect some of these pathogens in the red fox (Vulpes vulpes) population in Croatia. A total of 179 blood samples from foxes from nine districts were analysed. The SNAP ^® 4Dx ^® Plus rapid test was used to detect circulating D. immitis antigen and antibodies against B. burgdorferi, A. phagocytophilum/Anaplasma platys, and Ehrlichia canis/Ehrlichia ewingii. Circulating D. immitis antigen was detected in 6.70% of the samples (95% CI: 3.20–10.19%), while antibodies against A. phagocytophilum/A. platys were found in 10.06% (95% CI: 5.8–14.25%). Only one sample was positive for B. burgdorferi, while no antibodies were detected for E. canis/E. ewingii. Spatial analysis revealed statistically significant differences in prevalence by geographical region (district) and age, while no significant correlations were found. In the standard PCR analysis, DNA of D. immitis was not detected in any of the eight positive and eight negative SNAP ^® 4Dx ^® Plus samples. D. repens, A. reconditum, or co-infections were also not detected by PCR. Of the nine samples that tested positive for A. phagocytophilum/A. platys antibodies, four were confirmed to be positive for A. phagocytophilum by nested and semi-nested PCR targeting the 16S rRNA and GroEL genes. Phylogenetic analysis revealed similarities with various European strains, including zoonotic strains. This study is the first molecular detection of A. phagocytophilum from blood samples of red foxes in Croatia. The results show that red foxes are not free from infections such as anaplasmosis and dirofilariasis, emphasising their possible role in the maintenance and transmission of these pathogens in certain regions of Croatia. These results underline the need for further research to better understand the epidemiological importance of red foxes in the spread of vector-borne diseases. Full article