Search Results (6)

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

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

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

The etiology of feline inflammatory bronchial disease is poorly understood. This study compares the degree of allergen-specific serum IgE responses between cats with feline asthma, chronic bronchitis, mixed inflammation, and clinically healthy cats (HCs). The retrospective case–control study used serum from eighteen cats with eosinophilic inflammation (EI), ten with neutrophilic inflammation (NI), six with mixed inflammation (MI), and fourteen HCs. Affected cats were categorized into groups based on bronchoalveolar lavage cytology. The measurement of IgE for 34 different allergens including fungal organisms, weeds, grasses, trees, mites, and insects was performed using an indirect ELISA. Positive reactions to allergens were detected in the serum of 17/18 cats with EI, 8/10 with NI, 6/6 with MI, and 11/14 HCs (p = 0.364). When overall positive reactions were compared between groups, cats with MI (p = <0.01) had significantly more positive reactions against mite allergens than HCs. Blood eosinophils inversely correlated with the absolute amount of allergen-specific serum IgE expressed in ELISA absorbance units (EAs) (p = 0.014). Sensitization against dust mites seems to be more prevalent in cats with MI. However, positive IgE reactions can be observed in healthy and diseased cats, and, therefore, need to be interpreted in the light of clinical findings and environmental conditions of individual patients. Full article

The objective of this study was to evaluate the prevalence of involvement of common viral organisms R. equi and K. pneumoniae and their clinicopathological and radiological features in respiratory disease of Malaysian domestic cats. A total of 34 feline cases with acute/chronic infectious respiratory disease signs were followed prospectively to investigate respiratory disease due to R. equi and K. pneumoniae and their relationship with concurrent viral infections in disease manifestation. All sampled cats (n = 27) were positive for FCoV antibodies and negative for FeLV. A significantly high antibody titer for FCV in n = 26 cases was also noticed. A single sample of pyothorax from a 3-months-old, non-vaccinated kitten was positive for R. equi. Bronchopneumonia with severe infiltration of the polymorphs and mononuclear inflammatory cells were prominent features of lungs histopathology from the kitten positive for R. equi. K. pneumoniae subsp. pneumoniae was confirmed from tracheal swabs of two cats. Histologically, the tracheal tissues of the two cats positive for K. pneumoniae were normal. In diagnostic imaging, epicenter of the infectious URT disease was nasal conchae rostrally and nasal turbinates caudally, however for infectious LRT disease was bronchial tree. Conclusively, infectious respiratory disease is a complex illness in cats, predominantly for unvaccinated kittens and young adult cats, especially those kept in multi-cat household or shelter environments because of the involvement of multiple bacterial and viral organisms as primary or secondary invaders. Clinicians should not preclude feline rhodococcosis from differentials, especially in kittens with pyothorax and less than one year of age. Unlike R. equi, K. pneumoniae has the potential to colonize URT of cats which might be disseminating further to cause LRT disease. Full article

Obesity is a nutritional disorder commonly diagnosed in adult cats that has been associated with an increased risk of different chronic diseases including respiratory diseases. The main objective of this study is to define if there is a relation between lung function measured by barometric whole-body plethysmography and obesity in cats with bronchoconstriction. Fifty-three cats were included in the study. All animals presented a bronchoconstriction status diagnosed with an Enhanced Pause (Penh) value higher than the reference range. Based on a standardized 9-point body condition scale, 36 cats were normal-weight cats (with BCS < 6), and 17 cats were considered overweight or obese cats (with BCS ≥ 6). Overweight cats were mainly male cats and older, and presented lower tidal volume values, lower minute volume values, and lower peak inspiratory and expiratory flows than normal-weight cats. According to the results of the present study, overweight cats showed a more compromised lung function parameters related to restrictive pattern compared with normal-weight cats. However, overweight cats did not show a higher bronchoconstriction level compared with normal-weight cats. Full article