Radiographic and computed tomographic evaluation of tracheal diameter and length in kittens.

OBJECTIVE: To measure the tracheal diameter and length in kittens using radiography and CT and to evaluate the concordance between measurements obtained with these 2 modalities. ANIMALS: 15 kittens with an estimated age of 12 weeks and mean body weight of 1.49 kg. METHODS: Radiographic and CT images were retrospectively evaluated to measure tracheal lengths and diameters. Tracheal diameters were measured at 5 different sites (A [at the level of the C2-3 intervertebral disk space], B [at the level of the C4-5 intervertebral disk space], C [at the cranial end of the manubrium sterni], D [at the level of the second rib], and E [1 cm cranial to the carina]) along the trachea. The cross-sectional area and transverse and vertical diameter ratios were calculated for each measurement site. RESULTS: The cross-sectional area was largest at site A and decreased from site C to site E. Based on the vertical diameter ratio, the tracheal shape was most circular at sites A and E, whereas from sites B to D, it was elliptical. The vertical diameters of the trachea on radiography and CT did not differ statistically significantly. However, the tracheal length measured on radiography was approximately 6 mm longer than that measured on CT (P < .05). CLINICAL RELEVANCE: Using the first rib as an anatomical reference, the placement of a cuffed endotracheal tube is recommended in kittens. In emergency situations, regression equations based on body weight may be helpful in predicting tracheal diameters.

Red Ginseng Dietary Fiber Shows Prebiotic Potential by Modulating Gut Microbiota in Dogs.

Red ginseng, widely used in traditional medicine for various conditions, imparts health benefits mainly by modulating the gut microbiota in humans. Given the similarities in gut microbiota between humans and dogs, red ginseng-derived dietary fiber may have prebiotic potential in dogs; however, its effects on the gut microbiota in dogs remain elusive. This double-blinded, longitudinal study investigated the impact of red ginseng dietary fiber on the gut microbiota and host response in dogs. A total of 40 healthy household dogs were randomly assigned to low-dose (n = 12), high-dose (n = 16), or control (n = 12) groups and fed a normal diet supplemented with red ginseng dietary fiber (3 g/5 kg body weight per day, 8 g/5 kg per day, or no supplement, respectively) for 8 weeks. The gut microbiota of the dogs was analyzed at 4 weeks and 8 weeks using 16S rRNA gene sequencing of fecal samples. Alpha diversity was significantly increased at 8 and 4 weeks in the low-dose and high-dose groups, respectively. Moreover, biomarker analysis showed that short-chain fatty acid producers such as Sarcina and Proteiniclasticum were significantly enriched, while potential pathogens such as Helicobacter were significantly decreased, indicating the increased gut health and pathogen resistance by red ginseng dietary fiber. Microbial network analysis showed that the complexity of microbial interactions was increased by both doses, indicating the increased stability of the gut microbiota. These findings suggest that red ginseng-derived dietary fiber could be used as a prebiotic to modulate gut microbiota and improve gut health in dogs. IMPORTANCE The canine gut microbiota is an attractive model for translational studies, as it responds to dietary interventions similarly to those in humans. Investigating the gut microbiota of household dogs that share the environment with humans can produce highly generalizable and reproducible results owing to their representativeness of the general canine population. This double-blind and longitudinal study investigated the impact of dietary fiber derived from red ginseng on the gut microbiota of household dogs. Red ginseng dietary fiber altered the canine gut microbiota by increasing diversity, enriching short-chain fatty acid-producing microbes, decreasing potential pathogens, and increasing the complexity of microbial interactions. These findings indicate that red ginseng-derived dietary fiber may promote canine gut health by modulating gut microbiota, suggesting the possibility of its use as a potential prebiotic.