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.

Quantitative PCR and Cytology of Bronchoalveolar Lavage Fluid in Dogs with Bordetella bronchiseptica Infection.

BACKGROUND: The use of quantitative PCR (qPCR) for detection of Bordetella bronchiseptica in bronchoalveolar lavage fluid (BALF) and demonstration of bacteria adhering to ciliated epithelial cells in BALF or bronchial brushing fluid (BBF) has not been assessed in a series of affected dogs. Coinfections can worsen the clinical severity in bordetellosis, but the specific association with Mycoplasma cynos has not been evaluated. OBJECTIVES: To assess the utility of culture, qPCR and cytologic examination of cytospin preparations in the diagnosis of bordetellosis in dogs and the influence of coinfection by M. cynos on disease severity. ANIMALS: Twenty-four referred dogs with B. bronchiseptica infection and 10 healthy dogs. METHODS: Retrospective case series. qPCR (B. bronchiseptica and M. cynos) and culture results from BALF were recorded. Cytospin preparations from BALF and BBF were reviewed. qPCR on BALF from 10 healthy dogs were used as negative control. RESULTS: The BALF culture and qPCR detected B. bronchiseptica in 14/24 and 18/18 dogs, respectively. Coccobacilli were found adhering to ciliated epithelial cells in 20 of the 21 BALF cytologic preparations where epithelial cells were found, and 2/3 BBF cytologic preparations. Quantitative PCR detected a low level of B. bronchiseptica in one healthy dog. The frequency of detection of M. cynos was not significantly different in B. bronchiseptica (9/17 dogs) compared with healthy dogs (2/10 dogs) (P = .09). CONCLUSION AND CLINICAL IMPORTANCE: Quantitative PCR detection of B. bronchiseptica in BALF appears to be a useful diagnostic tool. Cytologic examination of BALF or BBF, when positive, allows a rapid and reliable diagnosis.

Long-term follow-up in dogs with idiopathic eosinophilic bronchopneumopathy treated with inhaled steroid therapy.

BACKGROUND: Treatment of canine idiopathic eosinophilic bronchopneumopathy mainly consists of long-term oral corticosteroid therapy. To avoid side effects, inhaled steroid therapy has been increasingly used but long-term clinical response and potential side effects are sparsely described. OBJECTIVES: Description of clinical response and side effects with long-term fluticasone in dogs with eosinophilic bronchopneumopathy. METHODS: Case series of dogs with eosinophilic bronchopneumopathy and treated with fluticasone monotherapy for at least 6 months. Clinical response and side effects assessed by physical examination, standardised questionnaire and ACTH (corticotropin) stimulation test. RESULTS: Eight dogs were treated for between 6 months and 5 years. Cough initially improved in all dogs; two dogs remained free of clinical signs, three were well controlled, but three showed severe relapse. Pituitary-adrenal axis inhibition occurred in two dogs treated with fluticasone monotherapy for more than 2 years; only one dog had clinical signs of iatrogenic hyperadrenocorticism. CLINICAL SIGNIFICANCE: Fluticasone monotherapy allows initial improvement or remission in the majority of dogs but long-term treatment fails to resolve the cough in some individuals. In addition, such therapy may induce pituitary-adrenal axis inhibition. Prospective larger and randomised studies including both fluticasone and orally-treated dogs are needed to define the optimal treatment.

Detection of Angiostrongylus vasorum by quantitative PCR in bronchoalveolar lavage fluid in Belgian dogs.

OBJECTIVES: To describe Angiostrongylus vasorum infection in a series of clinical cases over a 12-month period, report the use of quantitative PCR on broncho-alveolar lavage fluid and investigate the -possibility of previously undiagnosed angiostrongylosis in a retrospective cohort of coughing and healthy dogs. METHODS: Pulmonary angiostrongylosis was diagnosed based on compatible clinical signs and positive quantitative PCR on broncho-alveolar lavage fluid and/or positive Baermann examination. Quantitative PCR was also performed retrospectively on broncho-alveolar lavage fluid from 65 dogs (55 coughing and 10 healthy dogs), examined between 2008 and 2014; results of Baermann examination were also available in 33 dogs. RESULTS: Seven young adult dogs from Southeastern Belgium with respiratory clinical signs were diagnosed with angiostrongylosis between March 2013 and April 2014. Positive broncho-alveolar lavage fluid quantitative PCR results and positive Baermann examination were obtained in 5/5 and 2/5 dogs, respectively. In the remaining two dogs, only Baermann analysis was performed. Among the retrospective cohorts, only one broncho-alveolar lavage fluid from a coughing dog was quantitative PCR-positive whereas all faecal samples were negative. CLINICAL SIGNIFICANCE: Until recently, canine angiostrongylosis was not reported in Belgium. It should now be included in the differential diagnosis of coughing Belgian dogs. Identification of affected dogs may be aided by quantitative PCR on broncho-alveolar lavage fluid.