Dog Trachea Research Articles

Genomic evidence and virulence properties decipher the extra-host origin of Bordetella bronchiseptica.

Until recently, members of the classical Bordetella species comprised only pathogenic bacteria that were thought to live exclusively in warm-blooded animals. The close phylogenetic relationship of Bordetella with Achromobacter and Alcaligenes, which include primarily environmental bacteria, suggests that the ancestral Bordetellae were probably free-living. Eventually, the Bordetella species evolved to infect and live within warm-blooded animals. The modern history of pathogens related to the genus Bordetella started towards the end of the 19th century when it was discovered in the infected respiratory epithelium of mammals, including humans. The first identified member was Bordetella pertussis, which causes whooping cough, a fatal disease in young children. In due course, B. bronchiseptica was recovered from the trachea and bronchi of dogs with distemper. Later, a second closely related human pathogen, B. parapertussis, was described as causing milder whooping cough. The classical Bordetellae are strictly host-associated pathogens transmitted via the host-to-host aerosol route. Recently, the B. bronchiseptica strain HT200 has been reported from a thermal spring exhibiting unique genomic features that were not previously observed in clinical strains. Therefore, it advocates that members of classical Bordetella species have evolved from environmental sources. This organism can be transmitted via environmental reservoirs as it can survive nutrient-limiting conditions and possesses a motile flagellum. This study aims to review the molecular basis of origin and virulence properties of obligate host-restricted and environmental strains of classical Bordetella.

Ventilator-Assisted Inspiratory and Expiratory Breath-Hold Thoracic Computed Tomographic Scans Can Detect Dynamic and Static Airway Collapse in Dogs with Limited Agreement with Tracheobronchoscopy.

Airway collapse (AC) in dogs includes a tracheal collapse, mainstem and lobar bronchial collapse, and bronchomalacia (i.e., segmental/subsegmental bronchial collapse). The clinical presentation of AC may overlap with non-collapsible airway disease (NCAD) or another non-lower airway respiratory disease (NLARD). This study determined whether paired inspiratory (I)/expiratory (E)-breath-hold computed tomography (I/E-BH CT) can detect a static and dynamic AC in dogs with spontaneous respiratory disease and it compared the CT-derived metrics of the AC to the tracheobronchoscopy metrics. The CT-acquired I and E diameter and cross-sectional area (CSA) for the trachea, mainstem and lobar bronchi in dogs with an AC (n = 16), NCAD (16), and NLARD (19) served for a dynamic percent of the airway narrowing (%AN) calculation. A scoring system assessed the bronchomalacia. The circularity was calculated for each airway. The results were compared to the tracheobronchoscopy collapse grading. In the dogs with an AC, the %AN was larger for the trachea, right mainstem bronchus and right middle lobar bronchus when they were compared to the dogs with NCAD and NLARD. Flattening was only identified for the trachea of the AC dogs. The agreement between the CT and tracheobronchoscopy scores was 20% from trachea to the lobar bronchi and 47% for the segmental/subsegmental bronchi. Paired I/E-BH CT can detect static and dynamic AC with limited agreement with the tracheobronchoscopy metrics. Independent scoring systems that are tailored to the clinical manifestations of functional impairments are needed.

Ionic Detergent Under Pressure-Vacuum as an Innovative Strategy to Generate Canine Tracheal Scaffold for Organ Engineering

Decellularized scaffolds applied in tissue engineering offer improvements, supplying the elevated necessity for organs and tissues for replacement. However, obtaining a functional trachea for autotransplantation or allotransplantation is tricky due to the organ anatomical and structural complexity. Most tracheal decellularization protocols are lengthy, expensive, and could damage the tracheal extracellular matrix (ECM) architecture and functionality. Here, we aimed to evaluate the effectiveness of 3 different decellularization protocols combined with chemical and physical methods to obtain acellular canine tracheal scaffolds. Six adult dog tracheas were incised (tracheal segments) resulting in 28 rings for control tissue and 84 rings for decellularization (5–7 mm thick). Subsequently, decellularized tracheal scaffolds were microscopically/macroscopically characterized by histological analysis (Hematoxylin-Eosin, Masson’s trichrome, Picrosirius red, Alcian blue, and Safranin O), immunohistochemistry for ECM components, scanning electron microscopy, and genomic DNA quantification. After decellularization, the tracheal tissue revealed reduced genomic DNA, and maintenance of ECM components preserved (structural proteins, adhesive glycoproteins, glycosaminoglycans and proteoglycans), suggesting ECM integrity and functionality. Comparatively, the combined ionic detergent with high vacuum pressure decellularization protocol revealed superior genomic DNA decrease (13.5 ng/mg) and improvement on glycosaminoglycans and proteoglycans preservation regarding the other decellularized trachea scaffolds and native tissue. Our results indicate that the 3 chemical/physical protocols reduce the decellularization time without ECM proteins damage. Notwithstanding, the use of ionic detergent under vacuum pressure was able to generate an innovative strategy to obtain acellular canine tracheal scaffolds with the highest levels of adhesive proteins that support its potentiality for recellularization and future tissue engineering application.

Radiographic vertical tracheal diameter assessment at different levels along the trachea as an alternative method for the evaluation of the tracheal diameter in non-brachycephalic small breed dogs

BackgroundTracheal narrowing due to congenital tracheal hypoplasia, acquired tracheal stenosis and tracheal collapse can lead to life-threatening respiratory distress. Tracheal hypoplasia has been identified in brachycephalic dog breeds, predominantly English Bulldogs, by measuring the tracheal diameter compared to the diameter of the thoracic inlet and creating a ratio. However, reference ranges for tracheal diameter have not been established for non-brachycephalic small breed dogs. It would be advantageous to have established tracheal diameters for non-brachycephalic small breed dogs, as these are the dogs most at risk of tracheal collapse. The main objective, of this study was to radiographically evaluate vertical tracheal diameter (VTD) at three standardized locations along the trachea of non-brachycephalic small breed dogs, in an attempt to further establish a screening diagnostic protocol for canine tracheal hypoplasia. Medical records and thoracic radiographs of non-brachycephalic small breed dogs without respiratory disease were reviewed. Right lateral radiographs were reviewed. The absolute and average VTDs at three locations (location A: caudal cervical VTD; location B thoracic inlet VTD; location C: intrathoracic VTD) were standardized by manubrium length (ML), as well as by the previously utilized thoracic inlet distance (Ti-D) and proximal 3rd rib width (PR3-W) to calculate manubrium-tracheal index (M-TI), thoracic inlet-tracheal index (Ti-TI), and proximal R3-tracheal score (PR3-TS), respectively. Correlations between averaged tracheal diameter and each of the ML, Ti-D, and PR3-W, and between M-TI and each of Ti-TI and PR3-TS were calculated.ResultsEighty-one healthy dogs met the criteria for inclusion. Significant differences (P < 0.0001) were identified among the mean values of the absolute and standardized VTDs at levels A, B, and C. The smallest tracheal diameter was identified at the level of the thoracic inlet (Level B).The average VTD correlated better with ML (rs = 0.82, P < 0.0001) compared to Ti-D and PR3-W. A relatively strong correlation (rs = 0.77, P < 0.0001) was identified between the averaged manubrium tracheal index (M-TI) and thoracic inlet tracheal index (Ti-TI).ConclusionM-TI is an appropriate alternative to Ti-TI and PR3-TS to radiographically evaluate VTD in dogs. M-TI < 0.43, < 0.34, or < 0.38 at level A, B, or C, respectively, may indicate tracheal hypoplasia in non-brachycephalic small breed dogs. Screening of canine VTD could be achieved using M-TI.

Efficacy of milbemycin oxime/afoxolaner chewable tablets (NEXGARD SPECTRA\xae) against Capillaria aerophila and Capillaria boehmi in naturally infected dogs

BackgroundCapillaria aerophila and Capillaria boehmi parasitize the respiratory system of wild and domestic carnivores. Capillaria aerophila inhabits the trachea and bronchi of dogs and cats, while C. boehmi affects the nasal cavities and sinuses of dogs. In dogs the infection may be subclinical or characterized by varying respiratory distress.MethodsThe present study evaluated the efficacy of an oral formulation containing milbemycin oxime and afoxolaner (NEXGARD SPECTRA®) in dogs naturally infected with C. aerophila and/or C. boehmi from three enzootic areas of Italy. Dogs were enrolled pending fecal examination and molecular confirmation of respiratory capillarioses. Dogs were allocated in two groups: Group 1 (G1, 25 dogs), treated with a negative control product with no anthelmintic activity (afoxolaner, NEXGARD®), and Group 2 (G2, 26 dogs), treated with NEXGARD SPECTRA®. At the day of treatment administration (Day 0), all dogs were clinically examined. Dogs were again subjected to clinical and fecal examinations at Days 28 (± 4) and 56 (± 2). The primary criterion for treatment efficacy was the reduction of fecal Capillaria egg counts in G2 compared with G1. The regression of/recovery from baseline clinical signs was considered as a further efficacy criterion.ResultsPercentage reduction of fecal Capillaria egg counts in the NEXGARD SPECTRA® group compared to the control group was > 97% on Day 28 and 100% on Day 56, respectively (p < 0.05 for both time points). Twelve of the 13 dogs in the NEXGARD SPECTRA® group with respiratory signs prior to treatment were free of clinical signs at the end of the study. Conversely, the six control group dogs with respiratory signs prior to treatment remained symptomatic.ConclusionsResults of the present study showed that NEXGARD SPECTRA® was safe and highly efficacious in the reduction of C. aerophila and C. boehmi eggs after one treatment with a complete reduction of the egg output after the second administration associated with a recovery from respiratory signs.Graphical

Mechanical properties of de-epithelialized tracheal allografts.

BackgroundMany studies have shown that mucosa-treated tracheas can be used for allotransplantation without the use of immunosuppressants. However, no literature has reported whether the transplanted trachea has normal biomechanics. In this study, fresh dog trachea was used as a control to determine the mechanical properties of allograft trachea after mucous membrane removal.MethodsCervical tracheas (~10 cm in length, consisting of the cartilage rings down to the tracheal carina) and the surrounding connective tissues were removed from 20 mixed-breed dogs and then divided into 4 groups with 5 samples in each group. The groups were defined as follows: group A, fresh canine tracheas without any treatment; group B, canine tracheas after sodium dodecyl sulphate (SDS) de-epithelialization; group C, canine tracheas implanted into the dorsal fascia of beagle dogs for 1 month after SDS de-epithelialization; group D, canine tracheas implanted into the dorsal fascia of beagle dogs for 6 months after SDS de-epithelialization. All heterotopically implanted beagle dogs were free of any immunosuppressive treatment. Uniaxial tensile (n=20) and compressive (n=20) experiments were performed on the 4 groups of trachea using a universal testing machine; the tensile load was recorded at 150% of the original tracheal length (50% displacement), and the compressive load was recorded at 50% of the initial anteroposterior diameter (50% displacement). The average difference in tensile and compressive loads between groups was compared by analysis of variance.ResultsNo significant difference was found in the mean compressive strength among groups (group A =2.38±0.87 N, group B =3.33±1.03 N, group C =5.39±2.44 N, group D =3.04±2.12 N; P=0.07 for all groups). The mean tensile strength of group C was 9.68±0.86 N, resulting in a significant difference in tensile strength compared to group A (22.51±3.91 N) and B (24.24±7.46 N) (P<0.001). No significant difference in tensile strength was observed among groups A, B, and D.ConclusionsThe de-epithelialized trachea showed no significant change in mechanical properties after 6 months of implantation.

Evaluation of regenerated tracheal cilia function on a collagen-conjugated scaffold in a canine model

It is unclear whether the movement and function of the regenerated cilia on collagen-conjugated artificial trachea are the same as those of normal cilia. This study assessed the ciliary beat frequency (CBF) and ciliary transport functions (CTFs) of regenerated cilia in a canine model. A tracheal defect introduced into the anterior portion of the cervical trachea of an adult beagle dog was covered with a collagen-conjugated prosthesis. Two months later, the trachea was harvested along the long axis, both from normal and regenerated regions. The cilia were stained with isothiocyanate-conjugated wheat germ agglutinin, and their movement was monitored with a high-speed camera to analyse CBF and CTF. Four samples each were obtained from the regenerated and normal regions for CBF analysis and 7 samples each were obtained for CTF analysis. The wheat germ agglutinin-stained cells showed well-regulated beats in both the regenerated and normal regions of the trachea. Mean CBF in the regenerated and normal regions did not differ significantly (7.11 ± 0.41 vs 7.14 ± 1.09 Hz; P = 981). By contrast, CTF was significantly lower in the regenerated region than in the normal region (30.0 ± 6.62 vs 7.43 ± 0.58 μm/s; P = 0.005). Mean CBF in the regenerated and normal regions did not differ significantly at 2 months. The CTF in the regenerated region recovered partially but remained lower than those in the normal region. Methods are needed to improve the CTF of regenerated cilia.

The Histology of the Trachea in Dogs

The trachea was collected from apparently normal six adult dogs of spitz breed aged between 2-4 years of age from the post-mortem of the Veterinary Pathology department. The aim of the study was to observe the histological details of the trachea in the spitz breed of dogs. The tracheal wall consisted of the mucosa, submucosa, hyaline cartilage, and adventitia. Tracheal mucosa was lined by a pseudostratified ciliated columnar epithelium with mucous secreting goblet cell and basal cells. Lamina propria was made up of loose connective tissue and contained some alveolar mucous glands. Muscularis mucosa was a thin layer with smooth muscle fibers arranged in a dispersed manner. The submucosa contained loose connective tissue with numerous mucous secreting tubule – acinar submucosal gland and was found related to the perichondrium of cartilaginous rings. The dense fibroelastic tissue was found between the cartilaginous rings. The cartilaginous rings were flattened in cross-section. Thin tunica adventitia of loose connective tissue and covered the cartilaginous rings. Trachealis muscle was found.

Cheap and easy use of a video laryngoscope as a guide for endotracheal intubation in dogs

BackgroundTracheal intubation is the second most dangerous procedures reflected in the ICU. It includes passing a plastic tube named endotracheal tube (ET) through the vocal cords into the trachea. Errors of this procedure like the placement of ET in the oesophagus or advancing the ET too far into one of the two lungs are life threatening.ObjectivesThis work was designed to provide cheap and quick technique to confirm proper ET tube placement by utilizing simple video laryngoscopy and using dogs as an animal model.Materials and methodsThis study was conducted on 20 dogs divided into two equal group (n = 10). The first group, in which a semi-flexible video laryngoscope (VLS) fitted with endotracheal tube was introduced and placed into the trachea of the experimental dogs. In the second group, dogs were intubated through soft and flexible video laryngoscope (VLS) fitted with the endotracheal tube. Number and time of the first attempt for introduction of ET were recorded.ResultsThe number of attempts was significantly (P < 0.05) lower and intubation time was significantly (P < 0.05) longer in semi-flexible VLS when compared to soft and flexible video laryngoscope. No complications (death, oesophageal intubation or dental injury) were recorded during the course of the study.ConclusionFlexible VLS is more applicable for endotracheal intubation in dogs. It is cheap and can be used for several times without any impairment of its function.

Pig tracheal patchy xenotransplantation in the dog

A long-segmental tracheal lesion is difficult to repair by tracheal allotransplantation due to the lack of a well-defined blood supply for blood vessel anastomosis. The donor trachea needs to be revascularized within a well-vascularized soft tissue flap for several months to allow successful trachea allotransplantation. To date, xenotransplantation using the wild-type or genetically modified pig has been widely studied. The object of this study was to evaluate the feasibility of a small-sized (2×2cm) wild-type pig tracheal patchy in a dog tracheal defect model before trying a long-segment tracheal defect model and using a genetically modified pig as a donor in dog xenotransplantation. Three healthy beagle dogs (8-9kg) were used as recipients, and one pig (20kg) was used as the donor. A pig cartilaginous tracheal patchy (2×2cm half tube) was sutured to the tracheal resected site in each dog. Antithymocyte globulin (2.5mg/kg infusion, D0 and 1), tacrolimus (4.5mg/kg, twice a day for 2months), and methylprednisolone sodium succinate (1mg/kg, IV, for 2days and tapering) were administered for immunosuppression. The levels IL-2 and IFN-γ in the serum were measured at D0, 7, and 28. Tracheoscopy was performed at D28, 60, and 90. The recipients were sacrificed at D90, and the expression of dog and pig genes in the graft was evaluated by PCR. Histopathological examination of the graft was conducted. All of the dogs survived without complications during the experimental period. Their IL-2 and IFN-γ levels were significantly increased at D7 after transplantation compared to D0 and D28 (P<0.05). The pig tracheal patchy site was open, and no stenosis was observed until D90 on tracheoscopy, when pale mucosa erosion was observed; there was also remnant suture material at D28. However, the tracheal patchy sites gradually became similar to normal mucosa at D60 and 90. The expression of pig genes was detected in the graft by PCR. Normal epithelium and CD3 cells were observed in the histological examination at D90. In this study, our data suggest that the pig tracheal patchy can be successfully engrafted into the trachea of dog, although erosion of mucosa on the graft was seen at D30, in spite of the discordant species.

Computed tomographic features of tracheal shapes and dimensions in awake dogs

There are several reports in the veterinary literature on tracheal assessment; however, there is a lack of studies on the trachea in voluntarily breathing dogs. The aim of this study was to describe the natural shape of the trachea in awake dogs and to assess tracheal dimensions and the width-to-height ratio. Thoracic computed tomographic images of awake small breed dogs without any signs of respiratory malfunction (n = 19) were evaluated. Each trachea was categorised into one of four different shapes: circular, horseshoe, crescent or focal dorsal invagination. The circular shape was prominent, particularly in the thoracic inlet and intrathoracic area, while the horseshoe shape was also normally present. In this group of normal dogs, there were no crescent-shaped tracheas, but focally invaginated tracheas were observed. The mean tracheal heights at five locations, namely the caudal endplate of the fourth cervical vertebra, cranial endplate of the seventh cervical vertebra, mid-body of the first thoracic vertebra, mid-body of the third thoracic vertebra, and 1 cm cranial to the carina were 9.12, 8.96, 9.34, 9.88 and 10.16 mm, respectively. The widths at these same sites were 12.26, 10.42, 10.07, 9.82 and 10.23 mm, respectively. The width-to-height ratios of each tracheal location were 1.38, 1.20, 1.10, 1.01 and 1.03, the last two of which are consistent with the circular shape of the intrathoracic trachea. Multi-detector computed tomography under non-general anaesthesia is a non-invasive and unparalleled imaging tool for describing tracheal appearance in healthy awake dogs.

Integrated Lung and Tracheal mRNA-Seq and miRNA-Seq Analysis of Dogs with an Avian-Like H5N1 Canine Influenza Virus Infection.

Avian-like H5N1 canine influenza virus (CIV) causes severe respiratory infections in dogs. However, the mechanism underlying H5N1 CIV infection in dogs is unknown. The present study aimed to identify differentially expressed miRNAs and mRNAs in the lungs and trachea in H5N1 CIV-infected dogs through a next-generation sequencing-based method. Eighteen 40-day-old beagles were inoculated intranasally with CIV, A/canine/01/Guangdong/2013 (H5N1) at a tissue culture infectious dose 50 (TCID50) of 106, and lung and tracheal tissues were harvested at 3 and 7 d post-inoculation. The tissues were processed for miRNA and mRNA analysis. By means of miRNA-gene expression integrative negative analysis, we found miRNA–mRNA pairs. Lung and trachea tissues showed 138 and 135 negative miRNA–mRNA pairs, respectively. One hundred and twenty negative miRNA–mRNA pairs were found between the different tissues. In particular, pathways including the influenza A pathway, chemokine signaling pathways, and the PI3K-Akt signaling pathway were significantly enriched in all groups in responses to virus infection. Furthermore, dysregulation of miRNA and mRNA expression was observed in the respiratory tract of H5N1 CIV-infected dogs and notably, TLR4 (miR-146), NF-κB (miR-34c) and CCL5 (miR-335), CCL10 (miR-8908-5p), and GNGT2 (miR-122) were found to play important roles in regulating pathways that resist virus infection. To our knowledge, the present study is the first to analyze miRNA and mRNA expression in H5N1 CIV-infected dogs; furthermore, the present findings provide insights into the molecular mechanisms underlying influenza virus infection.

Effect of self-expanding bare metal stents of different diameters on the trachea of dogs

Objective: To study the effect of self-expanding bare metal stents on the trachea of dogs, and therefore to provide useful information for choice of airway stents by interventional physicians. Methods: In this experiment, 8 beagles were randomly divided into 4 groups. Four self-expanding metal stents of different diameters (16, 18, 20 and 22 mm, respectively) were placed in the trachea of these beagles for 3 months and their impacts on normal trachea were observed. Results: In the 16 mm stent group (stent-to-airway diameter ratio 103%), good epithelialization was observed and the tracheal structure had no significant damage. In the 18 mm stent group (stent-to-airway diameter ratio 116%), slight granulation tissues were observed, but the cartilage and outer membrane were normal. In the 20 mm stent group (stent-to-airway diameter ratio 129%), severe granulation tissues were observed. Cartilage was damaged but outer membrane was normal. In the 22 mm stent group (stent-to-airway diameter ratio 142%), no obvious granulation tissues were found. Cartilage was normal, but outer membrane was ruptured. Conclusion: In a certain range, tracheal granulation tissues increased as the stent diameter increased. However, if the stent diameter continued to increase, a decreasing trend of tracheal granulation was observed, but severe tracheal injury by stent expansion force would occur.

Comparison of the efficacy of four endobronchial ablation techniques in dogs.

The present study aimed to evaluate the safety and efficacy of four commonly used ablation techniques, namely neodymium-doped yttrium aluminium garnet (Nd:YAG) laser therapy, argon plasma coagulation (APC), high-frequency electrocautery and CO2 cryotherapy. The techniques were performed at various powers or impedance settings, and for various durations, on the trachea of beagle dogs. Pathological changes of the tracheal wall were assessed by bronchoscopy. The endoscopic gross appearance of lesions induced by ablation treatments was consistent with the histopathological changes. The results suggested that cryotherapy was relatively safe, whereas APC induced superficial tissue coagulative necrosis. Furthermore, Nd:YAG laser therapy was the most efficient technique and showed the greatest penetration potential. In general, tissue injury was exacerbated with extended application time, at constant power or impedance. The safest application parameters were 20 W for ≤1 sec for Nd:YAG laser therapy, 40 W for ≤3 sec for electrocautery, 40 W for ≤5 sec for APC and 100 Ω for ≤120 sec for cryotherapy. At the maximum times, these settings resulted in identical pathological changes. Healing of the lesions following ablation was achieved within 3 weeks. The Nd:YAG laser, APC, electrocautery and cryotherapy endobronchial ablation techniques differed according to their potential and limitations for application on the trachea. However, when applied at specific combinations of power or impedance and duration, they exhibited similar efficacies.

Dysphagia Secondary to Spirocerca lupi in a German Shepherd Dog

Background: Spirocerca lupi is a nematode that causes nodules in the esophagus and aortic aneurysms in dogs. Animals are infected by eating intermediate host (beetle) containing infective larvae or consuming viscera containing parasitic cysts from paratenic hosts. Dogs commonly have a subclinical presentation, but the most common signs are vomiting and regurgitation. Visualizing nodules or neoplastic masses via esophagoscopy and the presence of S. lupi eggs in feces are the best diagnostic methods. Milbemycin oxime is effective as a treatment for S. lupi. The objective of this study was to describe the diagnostic and medical management of a patient with dysphagia secondary to esophageal S. lupi nodules. Case: A 7-year-old male German shepherd dog was referred for endoscopic examination. The animal presented with chronic severe dysphagia and weight loss with a presumptive diagnosis of an esophageal foreign body. At palpation of the neck, the dog was painful just dorsal to the cricoid cartilage and had submandibular lymphadenomegaly. The animal also exhibited a dropped jaw which could be returned to its normal position by manipulation. Radiographic examination demonstrated a radiopaque image compatible with a mass in the cranial esophagus just caudal to the upper esophageal sphincter. A fluoroscopy study was performed and confrmed the presence of a mass apparently within the esophageal wall preventing the passage of food. Additionally, in this case, small amounts of contrast medium were visualized passing into the dog trachea. The animal was hospitalized exhibiting odynophagia, dysphagia and regurgitation. Blood analysis revealed a hypochromic normocytic anemia, severe thrombocytopenia and hipoalbuminemia. A commercial ELISA test for Ehrlichia spp. and Anaplasma spp. was performed (SNAP 4Dx plus, IDEXX®). The test was positive for Ehrlichia spp. and doxycycline treatment was started. Fluoroscopy was performed using iodinated contrast, and we observed a soft tissue density structure at the ventral wall of the esophagus that was not permitting the passage of the contrast through the upper esophageal sphincter. One week after doxycycline treatment the animal showed a improvement, with appetite and increased weight. In addition, the dropping jaw was no longer evident, but, the dysphagia continued. Laboratory analyses were repeated, and values were within the normal ranges. Esophagoscopy was performed which allowed us to observe a mass suggestive of a nodule secondary to S. lupi. This nodule was found in the cranial esophagus and could not be biopsied. However S. lupi eggs were observed in the fecal study. The patient was treated with milbemycin oxime to which the patient responded favorably, regaining the ability to swallow and gaining weight. Discussion: Spirocercosis is a parasitic disease with a worldwide distribution which occurs mainly in warm climates as in the present case. Dogs often have a subclinical presentation; however when present, the most common clinical signs are regurgitation and vomiting. In the present case the patient had severe chronic dysphagia as the principal sign, which makes this case atypical. Dysphagia occurred in this case because a nodule was formed in the cranial esophagus, which is also rare. This location made it impossible to take endoscopic biopsies, as described by other authors. However, the diagnosis was made by identifying microscopic parasites eggs in the stool test. In addition, dog improved with medical treatment with milbemycin oxime, at the present, no longer shows dysphagia, odynophagia or coughs and has improved their body condition. This is the frst offcial report of the presence of canine Spirocerca lupi in Ciudad Juarez, Mexico. Finally, dysphagia is an uncommon sign in dogs with spirocercosis; however, esophageal nodules secondary to S. lupi should be considered as a cause of this sign. Keywords: endoscopy, milbemycin oxime, Spirocerca lupi, nodule, dysphagia, dog.

Hyperthermia and hypercapnia following two intravenous injections of atracurium in a dog

A three month old, 5 kg American Bulldog presented with severe dyspnoea and cyanosis seven hours after being submerged in a fresh-water paddling pool. Oxygen was supplemented using an oxygen...

Equine and Canine Influenza H3N8 Viruses Show Minimal Biological Differences Despite Phylogenetic Divergence.

The A/H3N8 canine influenza virus (CIV) emerged from A/H3N8 equine influenza virus (EIV) around the year 2000 through the transfer of a single virus from horses to dogs. We defined and compared the biological properties of EIV and CIV by examining their genetic variation, infection, and growth in different cell cultures, receptor specificity, hemagglutinin (HA) cleavage, and infection and growth in horse and dog tracheal explant cultures. Comparison of sequences of viruses from horses and dogs revealed mutations that may be linked to host adaptation and tropism. We prepared infectious clones of representative EIV and CIV strains that were similar to the consensus sequences of viruses from each host. The rescued viruses, including HA and neuraminidase (NA) double reassortants, exhibited similar degrees of long-term growth in MDCK cells. Different host cells showed various levels of susceptibility to infection, but no differences in infectivity were seen when comparing viruses. All viruses preferred α2-3- over α2-6-linked sialic acids for infections, and glycan microarray analysis showed that EIV and CIV HA-Fc fusion proteins bound only to α2-3-linked sialic acids. Cleavage assays showed that EIV and CIV HA proteins required trypsin for efficient cleavage, and no differences in cleavage efficiency were seen. Inoculation of the viruses into tracheal explants revealed similar levels of infection and replication by each virus in dog trachea, although EIV was more infectious in horse trachea than CIV. Influenza A viruses can cross species barriers and cause severe disease in their new hosts. Infections with highly pathogenic avian H5N1 virus and, more recently, avian H7N9 virus have resulted in high rates of lethality in humans. Unfortunately, our current understanding of how influenza viruses jump species barriers is limited. Our aim was to provide an overview and biological characterization of H3N8 equine and canine influenza viruses using various experimental approaches, since the canine virus emerged from horses approximately 15 years ago. We showed that although there were numerous genetic differences between the equine and canine viruses, this variation did not result in dramatic biological differences between the viruses from the two hosts, and the viruses appeared phenotypically equivalent in most assays we conducted. These findings suggest that the cross-species transmission and adaptation of influenza viruses may be mediated by subtle changes in virus biology.

Ruptura traqueal em um cão – relato de caso

Changes in the cervical trachea in dogs and cats cause breathing difficulties and could be due to tumors, foreign bodies, tracheal colapse, hypoplasia, segmental stenosis, prolonged post-intubation stenosis and injuries. The latter, however, is the main cuase of breakage or tracheal stenosis, and may be caused by Fighting among animals or penetrating injuries. Lacerations can cause significant subcutaneous and mediastinal emphysema. This word reports the case of a tree-year-old mixed-breed dog with generalized subcutaneous emphysema and a two-day history of fight with another dog. The animal had no head injuries and was diagnosed with traumatic tracheal rupture, being submitted to tracheoplasty. The technique proved feasible and a great option for small lacerations.

Infection and pathogenesis of canine, equine, and human influenza viruses in canine tracheas.

Influenza A viruses (IAVs) can jump species barriers and occasionally cause epidemics, epizootics, pandemics, and panzootics. Characterizing the infection dynamics at the target tissues of natural hosts is central to understanding the mechanisms that control host range, tropism, and virulence. Canine influenza virus (CIV; H3N8) originated after the transfer of an equine influenza virus (EIV) into dogs. Thus, comparing CIV and EIV isolates provides an opportunity to study the determinants of influenza virus emergence. Here we characterize the replication of canine, equine, and human IAVs in the trachea of the dog, a species to which humans are heavily exposed. We define a phenotype of infection for CIV, which is characterized by high levels of virus replication and extensive tissue damage. CIV was compared to evolutionarily distinct EIVs, and the early EIV isolates showed an impaired ability to infect dog tracheas, while EIVs that circulated near the time of CIV emergence exhibited a CIV-like infection phenotype. Inoculating dog tracheas with various human IAVs (hIAVs) showed that they infected the tracheal epithelium with various efficiencies depending on the virus tested. Finally, we show that reassortant viruses carrying gene segments of CIV and hIAV are viable and that addition of the hemagglutinin (HA) and neuraminidase (NA) of CIV to the 2009 human pandemic virus results in a virus that replicates at high levels and causes significant lesions. This provides important insights into the role of evolution on viral emergence and on the role of HA and NA as determinants of pathogenicity. Influenza A viruses (IAVs) have entered new host species in recent history, sometimes with devastating consequences. Canine influenza virus (CIV) H3N8 originated from a direct transfer of an equine influenza virus (EIV) in the early 2000s. We studied the infection patterns of IAVs that circulate in dogs or to which dogs are commonly exposed and showed that CIV emergence was likely caused by an adaptive driver, as evolutionarily distinct EIVs display distinct infection phenotypes. We also showed that many human viruses can infect dog tracheas and that reassortment with CIV results in viable viruses. Finally, we showed that the hemagglutinin and neuraminidase of CIV act as virulence factors. Our findings have significant implications because they show that dogs might act as "mixing vessels" in which novel viruses with pandemic potential could emerge and also provide experimental evidence supporting the role of viral evolution in influenza virus emergence.

Mucoactive effects of naringin in lipopolysaccharide-induced acute lung injury mice and beagle dogs

Our previous study has demonstrated that naringin attenuates EGF-induced MUC5AC hypersecretion in A549 cells by suppressing the cooperative activities of MAPKs/AP-1 and IKKs/IκB/NF-κB signaling pathways. However, the volume of airway mucus is determined by two factors including the number of mucous cells and capacity of mucus secretion. The aim of the present study is to explore the mucoactive effects of naringin in lipopolysaccharide (LPS)-induced acute lung injury (ALI) mice and beagle dogs. The results demonstrated that naringin of 12.4mg/kg treatment significantly decreased LPS-induced enhancement of sputum volume and pulmonary inflammation, remarkably increased the subglottic sputum volume and solids content in sputum of lower trachea, while partially, but not fully, significantly increased the elasticity and viscosity of sputum in lower trachea of beagle dogs. Moreover, the MUC5AC content in BALF and goblet-cells in large airways of LPS-induced ALI mice were significantly attenuated by dexamethasone (5mg/kg), ambroxol (25mg/kg), and naringin (15, 60mg/kg). However, the goblet-cells hyperplasia in small airways induced by LPS was only significantly inhibited by dexamethasone and naringin (60mg/kg). In conclusion, naringin exhibits mucoactive effects through multiple targets which including reduction of goblet cells hyperplasia and mucus hypersecretion, as well as promotion of sputum excretion.