Alterations of the lung microbiota (LM) are associated with clinical features in chronic lung diseases (CLDs) with growing evidence that an altered LM contributes to the pathogenesis of such disorders. The common use of antimicrobial drugs in the management of CLDs likely represents a confounding factor in the study of the LM. The aim of the present study was to assess the effect of oral administration of amoxicillin/clavulanic acid (AC) on the LM in healthy dogs (n = 6) at short (immediately after stopping AC [D10]) and medium-term (16 days after stopping AC [D26]). Metagenetic analyses were performed on the V1–V3 hypervariable region of 16S rDNA after extraction of total bacterial DNA from samples of bronchoalveolar lavage fluid (BALF). AC did not induce significant changes in BALF cellular counts or in the bacterial load or microbial richness, evenness and α-diversity, while the β-diversity was clearly modified at D10 compared with D0 (before AC administration) and D26 (P < 0.01). The relative abundance of Bacteroidetes and Proteobacteria increased at D10 (P < 0.01) in comparison with D0 and D26 (P < 0.01). The relative abundance of Firmicutes decreased from D0 to D10 (P < 0.01) and increased from D10 to D26 (P < 0.01), but was still lower than at D0 (P < 0.01). The proportion of Actinobacteria increased at D26 compared with D0 and D10 (P < 0.01). Significant differences between timepoints at the level of family, genus or species were not found. In conclusion, in healthy dogs, oral administration of AC induces significant changes in LM at the phyla level and in the β-diversity. Most changes normalize within 2 weeks after discontinuation of AC.

Background Extrinsic and intrinsic factors have been shown to influence nasal microbiota (NM) in humans. Very few studies investigated the association between nasal microbiota and factors such as facial/body conformation, age, and environment in dogs. The objectives are to investigate variations in NM in healthy dogs with different facial and body conformations. A total of 46 dogs of different age, living environment and from 3 different breed groups were recruited: 22 meso−/dolichocephalic medium to large breed dogs, 12 brachycephalic dogs and 12 terrier breeds. The nasal bacterial microbiota was assessed through sequencing of 16S rRNA gene (V1-V3 regions) amplicons. Results We showed major differences in the NM composition together with increased richness and α-diversity in brachycephalic dogs, compared to meso−/dolichocephalic medium to large dogs and dogs from terrier breeds. Conclusion Healthy brachycephalic breeds and their unique facial conformation is associated with a distinct NM profile. Description of the NM in healthy dogs serves as a foundation for future researches assessing the changes associated with disease and the modulation of NM communities as a potential treatment.

Background: Literature about the lung microbiota (LM) in dogs is sparse. Influence of breed and living conditions on the LM in healthy dogs is currently unknown, as well as the influence of chronic respiratory diseases such as canine idiopathic pulmonary fibrosis (CIPF) in West highland white terriers (WHWTs). Aims of this study were (1) to assess the characteristics of the healthy LM according to breed and living conditions, and (2) to study LM changes associated with CIPF in WHWTs. Forty-five healthy dogs divided into 5 groups: domestic terriers (n = 10), domestic shepherds (n = 11), domestic brachycephalic dogs (n = 9), domestic WHWTs (n = 6) (H-WHWTs) and experimental beagles (n = 9) and 11 diseased WHWTs affected with CIPF (D-WHWTs) were included in the study to achieve those objectives.Results: In healthy domestic dogs, except in H-WHWTs, the presence of few discriminant genera in each type of breed was the only LM modification. LM of experimental dogs displayed a change in b-diversity and an increased richness compared with domestic dogs. Moreover, Prevotella_7 and Dubosiella genera were more abundant and 19 genera were discriminant in experimental dogs. LM of both H-WHWTs and D-WHWTs revealed increased abundance of 6 genera (Brochothrix, Curvibacter, Pseudarcicella, Flavobacteriaceae genus, Rhodoluna and Limnohabitans) compared with other healthy domestic dogs. Brochothrix and Pseudarcicella were also discriminant in D-WHWTs compared with H-WHWTs and other healthy domestic dogs.Conclusions: In domestic conditions, except for H-WHWT, the breed appears to have minor influence on the LM. LM modifications were found in experimental compared with domestic living conditions. LM modifications in H-WHWTs and D-WHWTs compared with other healthy domestic dogs were similar and seemed to be linked to the breed. Whether this breed difference might be related with the high susceptibility of WHWTs for CIPF requires further studies.

Objectives To determine whether there is a benefit of using pre‐ and postoperative antacid treatment in dogs undergoing surgery for brachycephalic syndrome. To assess the use of an obstruction manoeuvre during endoscopy for the detection of dynamic gastro‐oesophageal junction abnormalities. Materials and Methods Thirty‐six client‐owned brachycephalic dogs were prospectively included in a randomised trial. Antacid treatment was randomly prescribed in 18 dogs before and after surgery while the other 18 dogs did not receive any gastrointestinal medical treatment. At presentation, at the time of surgery and at recheck, digestive clinical signs and gastro‐oesophageal junction abnormalities were assessed using specific scores. Gastro‐oesophageal junction abnormalities were assessed during endoscopy in standard conditions as well as during endotracheal tube obstruction. This manoeuvre was also applied in an unrelated control group. Results The results suggest a beneficial effect of antacid treatment on the improvement of digestive clinical signs and lesions in dogs with brachycephalic syndrome undergoing surgery. At postsurgical control 83% of dogs had a digestive clinical score ≤1 in the treated group in contrast to 44% in the non‐treated group and 39% of dogs had a gastro‐oesophageal abnormalities score (during obstruction manoeuvre) ≤1 in the treated group in contrast to 16.7% in the non‐treated group. The use of the obstruction manoeuvre during endoscopic assessment in a control group revealed that gastro‐oesophageal junction movements are negligible in healthy animals. Clinical Significance The addition of antacid treatment during the pre‐ and postoperative period for brachycephalic dogs undergoing surgery may result in a faster and greater improvement in treated dogs. The obstruction manoeuvre is an interesting technique to improve detection of gastro‐oesophageal junction abnormalities.

Objectives To compare two minimally invasive enilconazole infusion protocols for the treatment of canine sinonasal aspergillosis and evaluate the importance of complete endoscopic debridement in determining first treatment success rate. Materials and Methods Data for 48 dogs with confirmed sinonasal aspergillosis treated with endoscopic debridement followed by per‐endoscopic enilconazole infusion were collected. Twenty‐four dogs were treated according to the previously published 1‐hour infusion protocol and 24 dogs underwent a simplified 15‐minute infusion protocol. Completeness of debridement, evaluated as partial or complete at the end of the procedure and outcome after one or several treatments were assessed in all dogs. Multi‐variable analysis was performed to derive odds ratios and 95% confidence intervals. Results The median duration of the simplified protocol – 92∙3 minutes (range 40 to 140) – was substantially shorter than the duration of the previous protocol – 201∙3 minutes (range 120 to 265). First treatment success rates were 58 and 62∙5% for the previous and simplified protocol, respectively. Overall treatment success rate was similar in both groups (96%). Complete debridement was associated with an improved first treatment success rate compared to partial debridement. Clinical Significance The simplified protocol is a valid alternative approach to the treatment of sinonasal aspergillosis. Completeness of endoscopic debridement before infusion is an important step for the success of treatment in canine sinonasal aspergillosis.