Comparison of postprandial and ceruletide serum bile acid stimulation in dogs

BACKGROUND: Postprandial (PP) serum bile acid (SBA) stimulation is an important test for detecting hepatic dysfunction in dogs. However, this test is influenced by numerous variables, and a standardized approach using an injectable cholecystokinin analog (ceruletide) may be advantageous. HYPOTHESIS: Ceruletide SBA stimulation test is more sensitive than PP SBA stimulation in dogs. ANIMALS: Animals with portosystemic shunt (PSS) (n = 11) and dogs with upper respiratory disease (URD) (n = 9) were investigated. Healthy dogs (n = 13) and dogs with other diseases (n = 17) served as controls. METHODS: All dogs underwent SBA stimulation with food and ceruletide. Stimulation blood samples were drawn at 60/120 minutes and 20/30/40 minutes, respectively. Results were compared statistically, and the sensitivity and specificity were determined with receiver-operating characteristic curves. RESULTS: Stimulated SBA were significantly higher in both study groups than in controls. For dogs with PSS, the sensitivity and specificity (>35 micromol/L) were 100% postprandially (120 minutes) and 91 and 100%, respectively, postceruletide (30 minutes). The difference between these values was not statistically significant. For dogs with URD, the sensitivity and specificity (>22 micromol/L) were 44 and 88% postprandially (120 minutes) and 100 and 88% postceruletide (30 minutes). CONCLUSIONS AND CLINICAL IMPORTANCE: Ceruletide SBA stimulation circumvents exogenous and endogenous influences associated with PP SBA stimulation. The results indicate that ceruletide SBA stimulation performs as well as PP SBA stimulation in dogs with PSS and is more sensitive for the detection of hepatic dysfunction in dogs with URD.     

Signalment,Clinical Presentation,Concurrent Diseases,and Diagnostic Findings in 28 Dogs with Dynamic Pharyngeal Collapse (2008–2013)

Background

Most information about pharyngeal collapse in dogs is anecdotal and extrapolated from human medicine. A single case report describing dynamic pharyngeal collapse in a cat has been published, but there is no literature describing this disease process in dogs.

Objective

To describe the signalment, clinical presentation, concurrent disease processes, and imaging findings of a population of client‐owned dogs with pharyngeal collapse.

Animals

Twenty‐eight client‐owned dogs with pharyngeal collapse.

Methods

Radiology reports of dogs for which fluoroscopy of the respiratory system was performed were reviewed retrospectively. Patients with a fluoroscopic diagnosis of pharyngeal collapse were included in the study population. Data regarding clinical signs, diagnostic, and pathologic findings were evaluated.

Results

Twenty‐eight dogs met the inclusion criteria. The median age of affected patients was 6.6 years, whereas median body condition score was 7/9. The most common clinical signs were coughing (n = 20) and stertor (n = 5). In 27 of 28 cases, a concurrent or previously diagnosed cardiopulmonary disorder was detected. The most common concurrent disease processes were mainstem bronchi collapse (n = 18), tracheal collapse (n = 17), and brachycephalic airway syndrome (n = 8). Fluoroscopy identified complete pharyngeal collapse in 20 of 28 dogs.

Conclusions

Pharyngeal collapse is a complex disease process that likely is secondary to long‐term negative pressure gradients and anatomic and functional abnormalities. Based on the findings of this study, pharyngeal fluoroscopy may be useful diagnostic test in patients with suspected tracheal and mainstem bronchial collapse to identify concurrent pharyngeal collapse.     

The prevalence of dynamic pharyngeal collapse is high in brachycephalic dogs undergoing videofluoroscopy

The aim of this retrospective study was to determine the frequency of pharyngeal collapse in a large group of brachycephalic dogs undergoing videofluoroscopic assessment of swallowing or airway diameter. We hypothesized that brachycephalic dogs would have pharyngeal collapse more frequently than dolichocephalic or mesocephalic dogs with or without airway collapse. The medical records database was searched for brachycephalic dogs undergoing videofluoroscopy of swallowing or airway diameter between January 1, 2006 and December 31, 2015. A cohort of dolichocephalic/mesocephalic dogs with videofluoroscopically confirmed airway collapse was age and time matched for comparison. A control group of dolichocephalic/mesocephalic dogs that did not have documented airway collapse was also evaluated. All fluoroscopic studies were assessed by a board certified veterinary radiologist for the presence and degree of pharyngeal collapse. Results demonstrate that pharyngeal collapse was significantly more common in brachycephalic dogs (58/82; 72%) than in nonbrachycephalic dogs with (7/25; 28%) and without (2/30; 7%) airway collapse. Pharyngeal collapse is more prevalent in brachycephalic dogs undergoing videofluoroscopy than in dolichocephalic/mesocephalic dogs with or without airway collapse.     

Quantitative bacterial cultures and cytological examination of bronchoalveolar lavage specimens in dogs

Cytology and quantitative bacterial cultures of lower respiratory tract secretions are widely used in human medicine to differentiate airway infection from simple bacterial colonization. A retrospective study was conducted to determine the usefulness of quantitative aerobic cultures and Gram stain intracellular bacteria counts from bronchoalveolar lavage (BAL) specimens in dogs in diagnosing lower respiratory tract infection (LRTI) and to determine whether chronic bronchitis is associated with marked bacterial growth in dogs. The threshold determined to define clinically relevant bacterial growth was 1.7 x 10(3) colony-forming units per milliliter of BAL fluid. We used this threshold and found that diagnostic sensitivity and specificity were 86% and 100%, respectively. With a threshold for infection of >2 intracellular bacteria observed in any of 50 fields, microscopic examination of Gram stain BAL preparations had a sensitivity of 71% and a specificity of 97% in establishing LRTI. There was a high correlation between bacterial morphology on BAL Gram stain and bacterial cultures. Combining the results of intracellular bacteria counts from the BAL Gram stain with those from the quantitative cultures, the sensitivity in diagnosing LRTI was 87% and the specificity was 97%. BAL quantitative cultures as well as quantitating intracellular bacteria on Gram stain BAL cytology were revealed to be useful in identifying LRTI in dogs. Chronic bronchitis does not appear to be associated with marked bacterial growth in dogs.     

CONGENITAL TRACHEAL COLLAPSE IN A PIGLET

Tracheal collapse was diagnosed radiographically in an eight-day-old Yorkshire-cross piglet presented with acute onset of inspiratory dyspnea. The diagnosis was confirmed by gross and microscopic pathology. This is the first reported example of tracheal collapse in a pig.     

鸡传染性支气管炎病毒感染无特定病原体鸡后气管黏膜扫描电镜观察

80只14日龄SPF鸡随机均分为试验组和对照组,试验组用鸡传染性支气管炎病毒(IBV)M41株人工感染,感染后5 d和7 d分别进行试验组及对照组气管黏膜扫描电镜观察,研究IBV入侵门户气管黏膜在感染IBV后的超微病变特点。结果表明:感染IBV后,气管表面纤毛集结成束,有大量黏液附着,纤毛粘连。气管黏膜结构受损,局部气管黏膜上皮脱落,固有层裸露,大量炎性细胞渗出。随感染期的延长,症状有加剧趋势。研究结果为IBV的发病机理提供了形态学上的依据。     

Episodic collapse in the horse

The term ‘collapse’ can be used to describe a variety of incidents in which a horse loses postural tone with or without progression to recumbency and with or without loss of consciousness. Depending on the aetiology of the condition the episode may be self‐limiting and may or may not recur. Alternatively the collapse may be secondary to serious injury or disease and require veterinary intervention. This article mainly discusses investigation of the former scenario of self‐limiting single or multiple episodes of collapse in apparently healthy horses. An overview of the various causes of collapse is followed by a suggested approach to the diagnosis of these challenging cases.     

Tidal Breathing Flow‐Volume Loop Analysis for the Diagnosis and Staging of Tracheal Collapse in Dogs

Background: Tracheoscopy is generally used for the diagnosis of tracheal collapse (TC) in dogs; yet, it is costly, requires anesthesia, and can irritate the airway. The tidal breathing flow‐volume loop (TBFVL) is a safe, quick, and noninvasive pulmonary function test currently used in humans. Hypothesis: TBFVL will differentiate dogs with TC from healthy controls and contribute to disease grading. Animals: Twenty‐eight dogs with naturally occurring TC and 10 healthy controls. Methods: Cross‐sectional, prospective clinical study: The 38 dogs were assigned to one of 4 groups based on tracheoscopy results: group A (n = 10, healthy controls), group B (n = 10, grade I TC), group C (n = 10, grade II TC), and group D (n = 8, grade III TC). The TBFVL measurement was performed on all dogs and loops were assessed for their shape. Forty‐four TBFVL parameters were calculated. Results: Two types of TBFVL shapes were identified: Type I, representative of the 10 healthy controls, and Type II, representative of the 28 dogs with TC. Statistical analysis showed the dogs could be differentiated into healthy or affected by TC by 3 indices, TE/TI (expiratory time divided by inspiratory time), TI/TTOT (inspiratory time divided by total respiratory time), and EF75/IF75 (expiratory flow at end tidal volume plus 75% end tidal volume divided by inspiratory flow at end tidal volume plus 75% end tidal volume). The TC could also be graded as mild‐moderate (grades I and II) or severe (grade III), showing a diagnostic value of 97.4%. Conclusion and Clinical Importance: TBFVL is accurate, quick, noninvasive, and safe and can contribute to the diagnosis of TC in dogs.     

Effects of Transportation on Redox Homeostasis and Tracheal Mucus

The aim of this pilot study was to document the effects of transportation on markers of oxidative stress (OS) in blood, exhaled breath condensate (EBC), and saliva and to explore their relationships with transport-related increases in tracheal mucus. Twelve horses, six Standardbred, and six Thoroughbred, aging from 3 to 8 years, underwent an 8-hour journey during which they had no access to food or water. Clinical examinations and sampling of blood, EBC, and saliva were performed preloading, at unloading, 12 and 24 hours, and 5 days after journey. Concentration of oxidants (reactive oxygen metabolites [ROMs], advanced oxidation protein product [AOPP], ceruloplasmin [CP], hydrogen peroxide in the EBC) and antioxidants (plasma total antioxidant status [PTAS] and saliva total antioxidant status [STAS], glutathione) were determined, and the oxidative stress index (OSI = ROMs/PTAS × 100) was calculated. Respiratory endoscopy was performed at preloading and unloading, and tracheal mucus was scored. Oxidative stress variables were analyzed using proc mixed procedure with time as the fixed factor, and the variation in mucus score was analyzed by median test. The relationships between OS markers and mucus score were examined by linear regression analysis. Transportation caused a significant increase in tracheal mucus and in the concentrations of ROMs, AOPP, CP, PTAS, and STAS (all P > .05). Tracheal mucus was positively associated with ROMs and OSI (R² = 57.8, P = .004; and R² = 70.3, P < .001, respectively). However, animals did not experience OS, as reflected in the lack of changes in OSI. Overall, although the transported horses experienced oxidative and respiratory challenges, they were able to maintain redox homeostasis and did not develop clinical disease.     

Upper airway dysfunction associated with collapse of the apex of the corniculate process of the left arytenoid cartilage during exercise in 15 horses

OBJECTIVE: To report dynamic collapse of the apex of the left corniculate process under the right corniculate process into the airway at the dorsal apposition of the paired arytenoid cartilages during exercise as a cause of upper airway dysfunction in horses. DESIGN: Retrospective study. ANIMALS: Fifteen horses with a history of poor performance and/or upper respiratory tract noise during exercise. METHODS: Video recordings of all horses referred for upper airway evaluation using high-speed treadmill videoendoscopy (HSTV) between January 1998 and December 2003 were reviewed. Records of horses that developed dynamic collapse of the apex of the left corniculate process into the airway were included. Clinical history, age, gender, breed, and use of the horse were retrieved. RESULTS: Of 309 horses referred for examination for poor performance and/or upper respiratory tract noise during exercise, 15 (4.9%) had collapse of the apex of the left corniculate process under the right and into the airway at the dorsal apposition between the paired arytenoid cartilages during HSTV. There were 3 females and 13 males, aged from 2 to 5 years. Five horses had previous surgery for left recurrent laryngeal neuropathy (RLN): 2 had nerve muscle pedicle graft and 3 had laryngeal prosthesis. During HSTV, all 15 horses had progressive collapse of the apex of the left corniculate process under the right at the dorsal apposition of the 2 arytenoid cartilages, and into the dorsal aspect of the rima glottidis. Review of video recordings revealed that collapse of the apex of the corniculate process was followed by progressive collapse of the left aryepiglottic fold and left vocal fold. The ventral aspect of the left corniculate cartilage maintained abduction in all horses. Two horses also had progressive collapse of the right vocal fold, 1 had rostral displacement of the palatopharyngeal arch, and another had dorsal displacement of the soft palate. CONCLUSIONS: Dynamic collapse of the apex of the left corniculate process of the arytenoid cartilage under the right is an uncommon cause of upper airway dysfunction in horses and the pathogenesis is unclear. We speculate that the left arytenoideus transversus muscle is unable to support the dorsal apposition between the arytenoid cartilages. This loss of support allows the elastic cartilage of the left corniculate process to collapse under the right and into the airway, as inspiratory pressure increases during exercise. This condition may be associated with an unusually advanced neuropathy of the adductor components of the left recurrent laryngeal nerve and may be an unusual manifestation of RLN; however, this is speculative and further investigation is required to determine its cause. CLINICAL RELEVANCE: Dynamic collapse of the apex of the left corniculate process and into the airway at the dorsal apposition between the paired arytenoid cartilages can only be diagnosed during HSTV. It is an uncommon cause of upper airway dysfunction but may affect the athletic potential of racing Thoroughbreds and Standardbreds.     

The Safety and efficacy of a new self-expandable intratracheal nitinol stent for the tracheal collapse in dogs

To evaluate the potential utility of a self-expandable intratracheal nitinol stent with flared ends for the treatment of tracheal collapse in dogs, endotracheal stenting therapy was performed under fluoroscopic guidance in four dogs with severe tracheal collapse. During the 4 to 7 month follow-up, after stent implantation, clinical signs, including dyspnea and respiratory distress, dramatically improved in all dogs. The radiographs showed that the implanted stents improved the tracheal collapse, and there were no side effects such as collapse, shortening or migration of the stents. In conclusion, the self-expandable intratracheal nitinol stents provided adequate stability to the trachea and were effective for attenuating the clinical signs associated with severe tracheal collapse.     

Comparison between tracheal ratio methods used by three observers at three occasions in English Bulldogs

Background

Tracheal hypoplasia is a congenital condition described in mainly brachycephalic breeds and is one component of the brachycephalic obstructive airway syndrome (BOAS). Two radiographic methods have been described to evaluate the dimensions of the tracheal diameter in dogs and to distinguish between hypoplastic and non-hypoplastic tracheas: the tracheal lumen diameter to thoracic inlet distance ratio (TD/TI) and the ratio between the thoracic tracheal luminal diameter and the width of the proximal third of the third rib (TT/3R). The purpose of this study was to compare these two published radiographic methods between observers, different measuring occasions and to investigate the effect on classification of dogs as having hypoplastic or non-hypoplastic tracheas using four previously published mean ratios as cut-offs (<0.11, <0.127 and <0.144 for the TD/TI and <2.0 for the TT/3R method).Three observers evaluated right and left lateral recumbent radiographs from 56 adult English Bulldogs independently on three different occasions. TD/TI and TT/3R ratios were calculated and correlated between measuring occasions. Kappa, observed, positive, and negative agreements were calculated between observers and measuring occasions. Number of hypoplastic and non-hypoplastic dogs for each method and occasion was determined using <0.11, <0.127 and <0.144 as cut-offs for TD/TI and <2.0 for TT/3R.

Results

Intraobserver agreement varied with kappa between 0.45-0.94 for the TD/TI and 0.20-0.86 for the TT/3R method. Interobserver kappa varied between 0.27-0.70 for the TD/TI method and between 0.05-0.57 for the TT/3R method. There was poor agreement in classifying English Bulldogs as tracheal hypoplastic or non-hypoplastic, depending on measuring method, cut-off value and observer.

Conclusions

The diagnostic value of both the TD/TI and TT/3R methods with such poor agreement is questionable, and significantly impacts their reliability for both clinical evaluation of dogs and use in health screening programs.     

Treatment of traumatic tracheal collapse with extraluminal titanium mesh screens

A 12‐year‐old Thoroughbred gelding presented with a history of exercise intolerance and inspiratory stridor. Physical examination revealed a blunt crush injury to the ventral neck and underlying trachea of unknown duration. Tracheoscopy revealed a grade 3 tracheal collapse. Surgical management of the case involved placement of extraluminal titanium mesh screens circumferentially around the trachea for complete support. During the period of hospitalisation, the only post operative complication was seroma formation, which resolved with routine care. Follow‐up after 5 years revealed no further evidence of exercise intolerance, inspiratory dyspnoea or stridor. The horse returned to his previous level of work as a show hunter.