Canine Eosinophilic Bronchopneumopathy

Feline herpesvirus-1-related multiple respiratory eosinophilic nodules in an adult cat receiving long-term oral prednisolone

Case summary

A 10-year-old male castrated domestic shorthair cat was presented for evaluation of a 3-day history of increased inspiratory effort. The cat had received prednisolone 1 mg/kg PO q24h for 1 year due to chronic diarrhea. On physical examination, the patient exhibited severe stridor, intermittent open-mouth breathing and bilateral mucopurulent nasal discharge. Subcutaneous emphysema was palpated over the dorsal cervical region. Mild hypoventilation (PvCO2 55.1 mmHg; approximate reference interval 35-45 mmHg) was identified. Cervicothoracic radiographs showed marked gas tracking within cervical soft tissues with concurrent laryngeal thickening, pulmonary nodules, a bronchial pulmonary pattern, pneumomediastinum and aerophagia. The cat was hospitalized and treated overnight with oxygen and intravenous fluid therapy before anesthesia the next day. On laryngoscopy, a large tracheal mass was observed arising from the right subglottic region and was removed using biopsy forceps. CT revealed an additional mass at the level of the tracheal bifurcation causing marked luminal narrowing of the trachea and proximal main bronchi. The cat made a good initial recovery, although moderate stridor persisted. Five days later, the cat was re-examined due to recurrence of respiratory distress and orthopnea, and the owner elected euthanasia. Histopathology revealed severe nodular obstructive eosinophilic plasmacytic laryngotracheitis with intranuclear inclusion bodies positive for feline herpesvirus-1 on immunohistochemistry.

Relevance and novel information

This report describes the presentation and management of a cat with respiratory distress secondary to intratracheal eosinophilic masses caused by feline herpesvirus-1. Although the outcome was ultimately unsatisfactory, to the authors' knowledge, this clinical presentation has not been previously reported.

Hematologic Abnormalities and Diseases Associated with Moderate-to-Marked Basophilia in a Large Cohort of Dogs

Basophilia is a rare hematologic finding in dogs. This research aimed to describe the hematologic and clinical characteristics of dogs with moderate-to-marked basophilia. CBC reports with blood smear examinations from dogs presented to the North Carolina State University Veterinary Teaching Hospital were retrospectively reviewed for basophilia (>193 cells/µL). We classified basophilia as moderate when counts were ≥500 cells/µL and marked when they reached ≥1000 cells/µL. We compared the hematologic and clinical profiles of dogs with moderate-to-marked basophilia (the basophilia group) to those without basophilia, serving as our control group. In addition, we investigated differences between dogs with marked basophilia versus those with moderate basophilia, as well as between dogs in the basophilia group with and without concurrent eosinophilia. Diseases associated with moderate-to-marked basophilia included eosinophilic lung disease (p < 0.0001), leukemia/myeloproliferative neoplasms (p = 0.004), parasitic infection (p = 0.004), mast cell tumor (p = 0.005), and inflammatory bowel disease (p = 0.02). Overall, dogs with marked basophilia had a lower frequency of inflammatory diseases (51% vs. 70%, p = 0.009) and a higher frequency of neoplastic diseases (48% vs. 26%, p = 0.003) compared to those with moderate basophilia. In the basophilia group, concurrent eosinophilia was only seen in 36% of dogs. Dogs with concurrent eosinophilia were more often diagnosed with inflammatory diseases (77% vs. 58%, p = 0.006), with fewer diagnoses of neoplasia (19% vs. 40%, p = 0.001), compared to dogs without concurrent eosinophilia. The findings of this study offer veterinary clinicians valuable guidance in determining diagnostic priorities for dogs with moderate-to-marked basophilia.

[Inhalation therapy in dogs and cats with chronic lower airway disease - a literature review]

Chronic respiratory diseases are prevalent medical conditions in dogs and cats requiring lifelong treatment. Mainstay of therapy for chronic inflammatory respiratory diseases are glucocorticoids. Concurrent treatment with bronchodilators may be necessary to control clinical signs sufficiently. Due to the successful use in people as well as subsequent reduction of adverse effects of long-term glucocorticoid therapy, inhalative therapy has become increasingly important in veterinary medicine as well. Primarily spacers or valved holding chambers, in combination with metered dose inhalers, are used in dogs and cats. The technical properties of these devices, as well as their use and maintenance will be described in the following article. Furthermore, the existing literature regarding efficacy of inhalative medications for therapy of chronic inflammatory airway diseases in dogs and cats will be summarized.

Topographical distribution and radiographic pattern of lung lesions in canine eosinophilic bronchopneumopathy

OBJECTIVES

To evaluate the radiographic lung pattern and topographical distribution in canine eosinophilic bronchopneumopathy.

MATERIALS AND METHODS

Medical records were retrospectively reviewed for dogs diagnosed with eosinophilic bronchopneumopathy. Lateral thoracic radiographs were examined for the presence of increased radiopacity, classification of pattern, topography of lung changes (cranioventral, perihilar, caudodorsal, caudoventral) and severity of pulmonary lesions.

RESULTS

Forty-four cases were identified with the Labrador retriever being the most commonly affected breed; there was a mean age of 5 years and an equal gender distribution. Coughing was the most common clinical sign. Circulating eosinophilia was present in 39% of dogs, with a mean peripheral eosinophilia of 5.1×10⁹ cells/L and a mean bronchoalveolar lavage fluid eosinophilia of 40%. Eighty percent of dogs had an abnormal lung pattern in at least one of the four lung fields; the remaining had normal thoracic radiographs. The most common patterns were a bronchial and a bronchointerstitial pattern, with 41 and 89% distribution to the caudodorsal lung field, respectively.

CLINICAL SIGNIFICANCE

A bronchial and bronchointerstitial pattern are the most common radiographic lung patterns seen in canine eosinophilic bronchopneumopathy with these patterns most frequently topographically distributed to at least the caudodorsal lung field. Furthermore, within the caudodorsal lung field, a bronchointerstitial pattern predominates. This radiographic and topographical finding may allow eosinophilic bronchopneumopathy to take precedence on a differential diagnoses list before confirmatory bronchoalveolar lavage fluid sampling.

Clinical features and long-term follow-up of 70 cases of canine idiopathic eosinophilic lung disease

BACKGROUND

Canine idiopathic eosinophilic lung disease (ELD) is sparsely documented in the literature.

METHODS

Clinical presentation and outcome of dogs diagnosed with ELD (eosinophilic bronchitis or eosinophilic bronchopneumonia) were reviewed. Subgroups were made based on chronicity of clinical signs and findings of thoracic imaging: NCI (no changes in thoracic imaging), BRON (bronchial/peribronchial pattern), INT (bronchointerstitial/interstitial/alveolar).

RESULTS

Seventy cases were included. There were more young to adult, crossbreed and female dogs. Compared with the other two groups NCI dogs showed lower bronchoalveolar lavage fluid eosinophilic pleocytosis and absence of circulating eosinophilia, bronchiectasis or death due to respiratory disease. All dogs responded clinically to corticosteroids. Median treatment duration was four months. Remission (no clinical signs after treatment discontinuation for >one month) and long-term remission (>six months) was achieved in 60 per cent, and 51 per cent of patients, respectively. Relapse occurred in 26 per cent of cases after remission but was rare (3 per cent) after long-term remission. The one-year, two-year and four-year survival to death due to respiratory disease was 98 per cent, 97 per cent and 91 per cent, respectively.

CONCLUSION

Prognosis and initial clinical response for ELD was generally good although achievement of long-term remission was only seen in 51 per cent of dogs. Different outcomes based on chronicity of signs, corticosteroid dose, thoracic imaging abnormalities and other clinical variables were not appreciated.

Eosinophilic bronchitis, eosinophilic granuloma, and eosinophilic bronchopneumopathy in 75 dogs (2006-2016)

Background

Eosinophilic lung disease is a poorly understood inflammatory airway disease that results in substantial morbidity.

Objective

To describe clinical findings in dogs with eosinophilic lung disease defined on the basis of radiographic, bronchoscopic, and bronchoalveolar lavage fluid (BAL) analysis. Categories included eosinophilic bronchitis (EB), eosinophilic granuloma (EG), and eosinophilic bronchopneumopathy (EBP).

Animals

Seventy‐five client owned dogs.

Methods

Medical records were retrospectively reviewed for dogs with idiopathic BAL fluid eosinophilia. Information abstracted included duration and nature of clinical signs, bronchoscopic findings, and laboratory data. Thoracic radiographs were evaluated for the pattern of infiltrate, bronchiectasis, and lymphadenomegaly.

Results

Thoracic radiographs were normal or demonstrated a bronchial pattern in 31 dogs assigned a diagnosis of EB. Nine dogs had intraluminal mass lesions and were bronchoscopically diagnosed with EG. The remaining 35 dogs were categorized as having EBP based on radiographic changes, yellow green mucus in the airways, mucosal changes, and airway collapse. Age and duration of cough did not differ among groups. Dogs with EB were less likely to have bronchiectasis or peripheral eosinophilia, had lower total nucleated cell count in BAL fluid, and lower percentage of eosinophils in BAL fluid compared to dogs in the other 2 groups. In contrast to previous reports, prolonged survival (>55 months) was documented in dogs with EG.

Conclusions and Clinical Importance

Dogs with eosinophilic lung disease can be categorized based on imaging, bronchoscopic and BAL fluid cytologic findings. Further studies are needed to establish response to treatment in these groups.

Detection of specific bacterial agents by quantitative PCR assays in the bronchoalveolar lavage fluid of dogs with eosinophilic bronchopneumopathy vs. dogs with chronic bronchitis and healthy dogs

In humans, Mycoplasma pneumoniae and Bordetella pertussis infections are suggested to trigger or exacerbate asthma. Whether Mycoplasma or Bordetella are associated with chronic inflammatory bronchial diseases in dogs has not been investigated. The aim of this study was to assess detection rates of Mycoplasma canis (M. canis), M. cynos and Bordetella bronchiseptica (Bb), in dogs with eosinophilic bronchopneumopathy (EBP) and chronic bronchitis (CB), compared with healthy dogs. Specific quantitative PCR (qPCR) analysis for M. canis, M. cynos and Bb were retrospectively performed on bronchoalveolar lavage fluid (BALF) collected from 24 dogs with EBP, 21 dogs with CB and 15 healthy dogs. Possible associations between qPCR results and age, BALF cytology or clinical severity scores (CSS) in dogs with EBP were investigated. There was no difference in M. canis, M. cynos and Bb detection rates in dogs with EBP (n=6, n=2 and n=6, respectively) and dogs with CB (n=2, n=2 and n=2, respectively) compared with control dogs (n=4, n=2 and n=2, respectively). In dogs with EBP, the proportion that were qPCR-positive for Bb was higher in dogs with higher CSS (P=0.014) and BALF from Bb-positive dogs had higher percentage of neutrophils (P<0.001). Among dogs that were qPCR-positive for Bb, moderate to high loads were only detected in dogs with EBP. M. canis and M. cynos detection was not associated with EBP or CB; higher Bb loads were only present in dogs with EBP and high CSS. A possible cause and effect relationship between Bb infection or load and EBP remains unclear and requires further investigation.

Tracheobronchial lesions in eosinophilic pneumonia

BACKGROUND

Eosinophilic pneumonia (EP) is characterized by eosinophil infiltration in the lung parenchyma. However, tracheobronchial lesions associated with the disease have been poorly described. To clarify the frequency and characteristics of cases with tracheobronchial lesions in EP, we performed a retrospective review of EP patients.

METHODS

We included 36 EP cases seen from January 2004 to December 2007 at the Kinki-Chuo Chest Medical Center. The incidence of tracheobronchial nodules and associated clinical features were analyzed.

RESULTS

Of these 36 patients, 29 had chronic eosinophilic pneumonia (CEP); 1, acute EP; 3, drug-induced EP; 2, allergic bronchopulmonary aspergillosis; and 1, parasite-related EP. Only 2 of the 29 CEP cases had tracheobronchial lesions. For both of these cases, bronchoscopy revealed multiple whitish nodules on the tracheobronchial mucosa. The associated histopathological findings revealed squamous metaplasia and eosinophil infiltration in the subepithelial region. In both cases, the nodules disappeared after steroid therapy. The prevalence of tracheobronchial lesions was 6.9% in CEP patients and 5.6% in EP patients overall. EP patients were divided into 3 groups: CEP with nodules (n=2), CEP without nodules (n=27), and other EP (n=7). We found that the CEP with nodules group showed a relatively higher incidence of respiratory symptoms, higher white blood cell (WBC) count, and higher levels of peripheral and bronchoalveolar eosinophilia than the other groups.

CONCLUSIONS

Tracheobronchial nodules represent rare observations within the EP population, which are likely to reflect a severe disease condition.

Spontaneous pneumothorax secondary to reactive bronchopneumopathy in a dog

CASE DESCRIPTION

An 8-year-old 38-kg (84-lb) castrated male German Shepherd Dog cross was evaluated because of respiratory distress secondary to pneumothorax (detected radio-graphically prior to referral).

CLINICAL FINDINGS

CT of the thorax confirmed the presence of pneumothorax and revealed pulmonary blebs without evidence of infiltrative pulmonary changes. A tentative diagnosis of primary spontaneous pneumothorax was made.

TREATMENT AND OUTCOME

Exploratory median sternotomy revealed emphysematous changes along the margins of all lung lobes, with the ventral margins of the left cranial, right cranial, and right middle lung lobes most affected. Partial lobectomies of the ventral aspects of these lobes were performed. Histologic examination of tissue samples from the lung lobes revealed diffuse smooth muscle hypertrophy of the terminal and respiratory bronchioles with moderate numbers of peribronchiolar eosinophils. Mucus plugs and mucous cell metaplasia within the airway epithelium were also evident. After surgery, clinical signs resolved and the dog was discharged from the hospital 2 days later. Eight months after surgery, the dog developed a mild cough, and treatment with prednisolone (tapering dosage starting at 0.5 mg/kg [0.023 mg/lb], PO, q 12 h) was initiated. Dosage reduction resulted in recurrence of coughing; however, with continued prednisolone treatment at a dosage of 0.5 mg/kg, PO, once daily, the dog was not coughing at 10 months after surgery.

CLINICAL RELEVANCE

Reactive bronchopneumopathy should be included as a differential diagnosis for spontaneous pneumothorax in dogs.

Cytological and parasitological analysis of bronchoalveolar lavage fluid for the diagnosis of Angiostrongylus vasorum infection in dogs

Bronchoalveolar lavage (BAL) is a procedure that retrieves cells and other elements from the lungs for evaluation, which helps in the diagnosis of many pulmonary diseases. The aims of this work were to perform this procedure in dogs in the acute and chronic phases of an Angiostrongylus vasorum infection for cytological analysis and to evaluate the potential of this technique as a diagnostic method for this lung-heart worm. The BAL procedure was performed through the use of an endotracheal tube on seven A. vasorum infected dogs and on five non-infected dogs lined as a control group. Sixty days post-infection (dpi) active and live larvae were retrieved from the bronchoalveolar fluid (BALF) of all infected dogs. Furthermore, in one animal it was possible to retrieve larvae in its BALF before the pre-patent period. This work reports that the A. vasorum infection resulted in an increase of relative neutrophils and eosinophils counts. In contrast, there was a significant decrease in the alveolar macrophage relative count in infected animals from 60 to 330 dpi. This study shows that the BAL is an accurate technique for the diagnosis of canine angiostrongylosis. Moreover, the technique allows us to retrieve cells and other elements that line the lung surface for cytological evaluation, which provides information about inflammatory diseases, and the diagnosis and prognosis of pulmonary parasites such as A. vasorum.