Background
Cats in respiratory distress have limited tolerance for manipulation, hindering clinical monitoring. Minute volume (MV) can be utilized to rate dyspnea in humans, but its relationship with ...respiratory distress in cats remains poorly investigated.
Hypothesis
Cats with respiratory distress will show higher MV per kg body weight (MV/BW) than normal cats, and the MV/BW increase will correlate with survival.
Animals
Fifty‐two cats with respiratory distress from lung parenchymal disease, pleural space disease, lower airway obstruction (LAO), or upper airway obstruction were recruited since 2014.
Methods
This is a prospective observational study. Study cats were placed in a transparent chamber, allowing clinicians to easily observe their breathing status and record ventilation using barometric whole‐body plethysmography (BWBP). Ventilatory variables of the 52 cats were compared with those of 14 historic control cats. Follow‐up data, including disease category, clinical outcomes, and survival, were prospectively collected.
Results
Cats in respiratory distress demonstrated significantly higher MV/BW (397 mL/kg; range, 158‐1240) than normal cats (269 mL/kg; range, 168‐389; P < .001). Among the etiologies, cats with LAO, parenchymal, and pleural space disease exhibited higher‐than‐normal MV/BW trends. A cutoff value of 373 mL/kg (1.4‐fold increase) indicated abnormally increased breathing efforts (sensitivity, 67%; specificity, 93%). MV/BW was independently associated with increased cardiorespiratory mortality in cats with respiratory distress (adjusted hazard ratio 1.17, 95% confidence interval CI 1.02‐1.35; P = .03).
Conclusions and Clinical Importance
Breathing efforts in cats can be noninvasively quantified using BWBP. Measurement of MV/BW could serve as a prognostic index for monitoring cats experiencing respiratory distress.
Background
Small‐breed dogs commonly have concurrent myxomatous mitral valve disease (MMVD) and lower respiratory tract disease (LRTD).
Hypothesis
Small‐breed dogs with preclinical MMVD and ...concurrent LRTD have more B‐lines on point‐of‐care lung ultrasound (POC‐LUS) compared to dogs without concurrent LRTD and are prone to misdiagnose as cardiogenic pulmonary edema (CPE).
Animals
A total of 114 small‐breed dogs with preclinical MMVD.
Methods
A prospective study was conducted, in which POC‐LUS was obtained and the number of B‐lines was calculated by a single clinician using the Veterinary Bedside Lung Ultrasound Examination protocol. The presence/absence of LRTD was assessed by clinicians blinded to the POC‐LUS results.
Results
Fifty and 64 dogs were in ACVIM stage B1 and B2, respectively. The presence of LRTD was prevalent in 74.6% (85/114) of small‐breed dogs with preclinical MMVD. When a previously reported criterion for CPE diagnosis (≥2 sites with >3 B‐lines/site) was applied, false‐positive results were observed in 15.8% (18/114) of dogs with preclinical MMVD. The summated number of B‐lines (3 vs. 1, P = .003), as well as the false‐positive rate (20% vs 3%, P = .04), were significantly higher in dogs with LRTD compared with dogs without LRTD. Multivariable logistic regression showed the presence of abnormalities other than B‐line on POC‐LUS (eg, thickened pleura or consolidation) could predict false‐positive results (odds ratio = 3.75, 95% confidence intervals 1.12‐12.54; P = .03) after adjustment for other clinical and echocardiographic factors.
Conclusions and Clinical Importance
Concurrent LRTD and abnormalities other than B‐lines should be considered in the interpretation of POC‐LUS in MMVD dogs.
Background
Indoor air pollution (IAP) leads to important respiratory morbidity and mortality in humans. Companion dogs and cats share the same household environment with their owners and are exposed ...to IAP.
Hypothesis
Pets with respiratory disease are more commonly exposed to indoor air pollutants in their homes and to worse air quality than pets without respiratory disease.
Animals
Three hundred and forty‐eight animals (230 dogs and 118 cats) were recruited.
Methods
Dogs and cats attending the National Taiwan University Veterinary Hospital were prospectively enrolled over a 12‐month period. Questionnaires were collected from pet owners regarding the status of signs of respiratory problem of animals and air pollutants in their homes. Clinical assessment was performed by veterinarians on all animals included in the case‐control study and the presence/absence of respiratory disease and diagnoses were recorded. Individual exposure to particulate matter of 2.5 μm or less (PM2.5) was estimated in the domestic microenvironment of the animals.
Results
Dogs with respiratory disease were more commonly exposed to incense burning than control dogs (30 versus 13%, P = .045), but household PM2.5 level was not different between dogs with and without respiratory disease median 30.8 μg/m3, range 10.8‐214.2 versus median 38.2 μg/m3, range 5.4‐69.4, P = .57. Signalment factors (age, body weight, and body condition score) instead of IAP factors were associated with respiratory disease in dogs using multivariable logistic regression. In contrast, household PM2.5 level was significantly higher in cats with respiratory disease than in control cats median 38.6 μg/m3, range 17.8‐131.2 versus median 27.4 μg/m3, range 15.4‐70.0, P = .017. Cats living in households with PM2.5 > 35 μg/m3 were more likely to have respiratory disease than those living in households with acceptable levels of PM2.5 (OR = 4.13, 95% CI 1.12‐15.27, P = .03).
Conclusions and Clinical Importance
The link between IAP and respiratory disease in dogs is complicated. An unacceptable level of household PM2.5 (>35 μg/m3) is significantly associated with respiratory disease in cats. The effect of IAP on the respiratory health of companion animals warrants further attention.
After the success of the first attempt to apply the technique described in the present study to a healthy cat, the option of CT scanning without general anaesthesia was provided to cat owners if ...thoracic CT imaging was suggested as a part of diagnostics according to the individual cat's medical condition, but there was concern about the anaesthetic risk. The final diagnoses (a clinical diagnosis, a laboratory-confirmed diagnosis or by necropsy) of the 18 diseased cats included pneumonia (6), primary lung cancer (4), metastasis (4), interstitial lung disease (3), diaphragmatic hernia (1), chylothorax caused by congestive heart failure (1) and severe atelectasis of multiple lung lobes due to congenital or acquired aetiology (1). The setback in these two cases was unexpected because the cats were quite cooperative with other manipulations, such as blood collection. ...which cat is able to tolerate the present methodology cannot be predicted before the trial. ...although the pros of using the present technique is the reduced cost and risk associated with sedation in comparison with general anaesthesia, the cons is the inability of applying inspiratory breath-hold technique to minimise atelectasis during CT scanning. 9 Respiratory motion artefact was also possible in spontaneously breathing animals and may cause blurriness in the images that affects quantitative measure of bronchial wall thickness or lung attenuation. 1 9 In conclusion, the present technique could effectively limit the patient's movement during thoracic CT scanning without causing complications or excessive stress in cats with a variety of diseases related to the respiratory tract.
Dynamic lower airway obstruction is the primary component of canine bronchomalacia, but the ventilatory function remains underinvestigated. This prospective study analyzed tidal breathing ...characteristics in 28 dogs, comprising 14 with severe bronchomalacia diagnosed by bronchoscopy versus 14 without respiratory disease. Spirometry was conducted in all dogs. Bronchoscopy with bronchoalveolar lavage or brush under anesthesia was performed in 14 dogs with cough and expiratory effort. Severe bronchomalacia was defined by the severity of collapse and total number of bronchi affected. Ventilatory characteristics were compared between groups. Results revealed that dogs with severe bronchomalacia had lower minute volume (218 vs 338 mL/kg, p = .039) and greater expiratory-to-inspiratory time ratio (1.55 vs 1.35, p = .01) compared to control dogs. The tidal breathing pattern of dogs with bronchomalacia was different from that of normal dogs, and the pattern differed from the concave or flat expiratory curves typical of lower airway obstruction. Compared to control dogs, dogs with severe bronchomalacia had a significantly prolonged low-flow expiratory phase (p < .001) on the flow-time plot and a more exponential shape of the expiratory curve (p < .001) on the volume-time plot. Flow-time index ExpLF/Te (>0.14) and volume-time index Vt-AUCexp (≤31%) had a high ROC-AUC (1.00, 95% confidence interval 0.88 to 1.00) in predicting severe bronchomalacia. In conclusion, the tidal breathing pattern identified here indicates abnormal and complicated ventilatory mechanics in dogs with severe bronchomalacia. The role of this pulmonary functional phenotype should be investigated for disease progression and therapeutic monitoring in canine bronchomalacia.
Background
Indoor air pollution (IAP) is an emerging issue for both human and veterinary patients under the concept of ‘One Health’. The association between IAP and respiratory disease in companion ...animals has been reported.
Objectives
The present study investigated the relationship between quantifiable indoor air quality and clinical characteristics of naturally acquired bronchial/lung disease in pet dogs and cats.
Methods
A total of 36 clinical cases (20 dogs and 16 cats) with naturally acquired bronchial/lung disease were prospectively recruited. Lower airway samples were collected and analysed, and clinical signs and the information from pulmonary function testing were examined. Indoor air quality was estimated by the average concentration of particles measuring ≤2.5 μm (PM2.5, μg/m3) and volatile organic compounds (VOC, ppm) in the animals’ domestic microenvironments.
Results
Exposure to IAP was not found to be correlated with the severity of clinical signs, pulmonary function changes or bronchoalveolar lavage fluid cytology in cats with bronchial/lung disease. However, a hypercellular response in canine lower airways was found to be associated with poor indoor air quality, including unacceptable indoor PM2.5 levels (>35 μg/m3) or increases in VOC concentration (>1 ppm) in places most commonly frequented by the dogs in the home.
Conclusions
Poor indoor air quality may exacerbate airway disease in pets and should not be ignored in modern society.
Pet dogs and cats with naturally acquired bronchial/lung disease are also likely to expose to unacceptable level of particles measuring ≤2.5 μm or volatile organic compounds in their homes. A hypercellular response in canine lower airways was found to be associated with poor indoor air quality, implying that exposure to indoor air pollution (IAP) could stimulate the mucosa and lead to further pathological changes in dogs. Possible threat of IAP is an emerging ‘One Health’ issue that affects both pets and their owners in modern society.
The premortem understanding of the role of feline coronavirus (FeCoV) in the lungs of cats is limited as viruses are seldom inspected in the bronchoalveolar lavage (BAL) specimens of small animal ...patients. This study retrospectively analyzed the prevalence of FeCoV in BAL samples from cats with atypical lower airway and lung disease, as well as the clinical characteristics, diagnostic findings, and follow-up information. Of 1162 clinical samples submitted for FeCoV RT-nPCR, 25 were BAL fluid. After excluding 1 case with chronic aspiration, FeCoV was found in 3/24 (13%) BAL specimens, with 2 having immunofluorescence staining confirming the presence of FeCoV within the cytoplasm of alveolar macrophages. The cats with FeCoV in BAL fluid more often had pulmonary nodular lesions (66% vs. 19%,
= 0.14) and multinucleated cells on cytology (100% vs. 48%,
= 0.22) compared to the cats without, but these differences did not reach statistical significance due to the small sample size. Three cats showed an initial positive response to the corticosteroid treatment based on the clinical signs and radiological findings, but the long-term prognosis varied. The clinical suspicion of FeCoV-associated pneumonia or pneumonitis was raised since no other pathogens were found after extensive investigations. Further studies are warranted to investigate the interaction between FeCoV and lung responses in cats.
Abstract
Background
Bronchiolar disorders are rarely recognized in cats. Constrictive bronchiolitis obliterans is characterized by concentric peribronchiolar fibrosis and inflammation of the ...bronchioles, but the underlying causes remain poorly understood in current small animal medicine.
Case presentation
A 9-year-old cat presented with paroxysmal tachypnea, infrequent cough and persistent labor breathing. Thoracic radiography showed lung hyperinflation and bronchointerstitial pattern, and pulmonary function assessment revealed flow limitation in the late-expiratory phase and poor response to short-acting bronchodilator. Dorsally distributed subpleural ground glass opacities with distinct margin and tree-in-bud opacities were observed on lung high-resolution computed tomography. The cat underwent bronchoalveolar lavage (BAL) and showed severe neutrophilic inflammation. Feline herpesvirus was the only pathogen detected in the BAL fluid. Multiple therapeutic attempts were unsuccessful and the cat died 8 weeks after the initial presentation. Necropsy revealed the infiltration of inflammatory cells, obstruction of the bronchiolar lumen, and submucosal concentric fibrosis suggesting constrictive bronchiolitis obliterans. Combining the pre- and post-mortem findings, as well as the time from symptom onset or BAL to necropsy, constrictive bronchiolitis obliterans was possibly triggered by a preceding feline herpesvirus infection in this case.
Conclusions
The history of nonvaccinated status, lower airway neutrophilic inflammation, and presence of feline herpesvirus in the BAL fluid without coexistence of other pathogens led to the presumption that constrictive bronchiolitis obliterans was induced by a preceding feline herpesvirus infection in this cat. The pathological changes of bronchiolitis obliterans induced by a preceding feline herpesvirus infection could be different from that of cats with acute herpesvirus pneumonia, such as intranuclear inclusions would disappear over time and were no longer found 7–10 days after inoculation. The presence of patchy distribution of subpleural ground glass opacities on lung high-resolution computed tomography should raise the suspicion of peribronchiolar fibrosis. Clinical awareness of bronchiolar disorders as a differential diagnosis is important in cats with lung hyperinflation and labored breathing who show poor reversibility to bronchodilator.
Chest ultrasonography has become an indispensable tool for pulmonary specialists in human medicine, but its current use in dogs and cats is primarily for emergency. The diagnostic performances of ...various ultrasonographic features other than comet-tail artifacts are of limited information in veterinary literatures. Therefore, the aims of this retrospective study were to investigate ultrasonographic findings in feline and canine respiratory patients with lung parenchymal and pleural space diseases, and to assess how ultrasonographic features correspond to specific diagnoses. Sixty-five non-emergency cases with radiographically identified lung parenchymal and pleural space abnormalities were included. Medical records and ultrasound video clips were reviewed, and additional follow-up information was subsequently collected. Common findings such as comet-tail artifacts (87.7% of cases), consolidation (84.6%), and thickened/irregular pleura (69.2%) were not distinguishable for a specific diagnosis. The presence of nodular/mass-like lesion (OR = 212,
< 0.001) and consolidated lesion with heteroechogenicity (OR = 240,
< 0.001) was significantly associated with and strongly predictive of neoplasia after age, body weight and other sonographic findings were adjusted. The finding of nodular/mass-like lesion has the best diagnostic performance (AUC = 0.93) for neoplasia, with sensitivity of 91.7% and specificity of 93.6%. For predicting a diagnosis of pneumonia, although several sonographic features were found to be statistically associated with pneumonia, only a negative finding of nodular/mass-like lesion showed good diagnostic performance (AUC = 0.83, sensitivity 95.7%, specificity 71%). These findings demonstrate the value of chest ultrasonography in predicting diagnosis in non-emergency cases. The application of thoracic ultrasound in small animal respiratory patients as part of non-invasive assessment warrants further investigation.
As a two-dimensional nanomaterial, bismuth oxybromide (BiOBr) have attracted tremendous interest in the area of visible-light photocatalysis since it can provide the internal electric field (IEF) ...through z-axis through its unique electronic band structure. However, the insufficient active sites and rapid recombination rate of charged carriers hamper the efficiency of the photocatalysis. To address these two major obstacles, an enticing strategy of constructing heterojunction was established by introducing Bi2O2(OH)(NO3) (BiON) in BiOBr with the same precursor. Through a facile one-pot hydrothermal synthesis, two Sillén-type layered photocatalysts, with intimately constructed ultrathin heterostructure, was synthesized by the co-precipitation method. In this work, the formation of Bismuth-based heterojunction for charge separation is established by the excessive bismuth nitrate, which subsequently participates with the in situ growth of ultrathin hierarchical microspheres. By attenuating the thickness of BiOBr from 20 nm to 8 nm with the aid of BiON, the photogenerated charges could migrate to the active sites through shorter charge diffusion pathway. Also, the BiOBr and BiON act as an active bridge to promote the separation of electron-hole pairs, which also brings out more active sites due to its increased specific surface area. BiON/BiOBr ultrathin hierarchical microspheres exhibited enhanced visible-light photocatalytic activity for decontaminating several types of pollutants. Besides, the activity of as-prepared BiON/BiOBr was further evaluated by inhibiting the growth of kanamycin-resistant bacteria strains. This study presents a novel strategy to incorporate the crystalline bismuth hydrate nitrate into BiOBr to form ultrathin hierarchical microspheres with high surface area for environmental remediation.
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•Ultrathin Bi2O2(OH)(NO3)/BiOBr microspheres with high specific surface area.•The incorporation of Bi2O2(OH)(NO3) improved the photocatalytic activity.•The formation of Bi2O2(OH)(NO3)/BiOBr composite is proposed by SEM images.•O2− and photogenerated holes dominate as main reactive species.
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