Objective: This study aims to develop formulas for estimating tracheal diameter and length in dogs using easily measurable anatomical parameters. Materials and Methods: The samples consisted of 20 dogs of various breeds, comprising 10 males and 10 females, sourced from cadavers. The measured parameters included occipital tuberosity to tail base (OT), eye angle to ear tragus, nose to ear tragus, inner vertical diameters (IVD), and tracheal length (TL). The study conducted correlation and linear regression analyses, and subsequently, the formulated models underwent validation using 16 live dogs. The results were compared to radiographic measurements. Results: Linear regression recommended formulas based on OT, resulting in IVD (mm) = 0.203 × OT – 3.724 (r2 = 0.608, p < 0.001) and TL (cm) = 0.346 × OT–3.773 (r2 = 0.837, p < 0.001). The predicted tracheal diameter and length from formulas were slightly smaller than radiographic measurements (IVD = 2.76 ± 1.85 mm, p < 0.0001 and TL = 2.07 ± 1.81 cm, p < 0.0001). Conclusion: These formulas offer a practical way to estimate tracheal dimensions in live dogs, facilitating the selection of suitable endotracheal tube sizes and insertion depth. Further studies with larger sample sizes and consistent measurement methods can enhance the accuracy of these findings.

Industrial hemp (Cannabis sativa L.) derivatives are emerging as functional ingredients in companion animal nutrition; however, their long-term effects on the canine gut microbiome remain unclear. This exploratory study investigated the impact of dietary supplementation with two hempseed-based formulations (fiber-rich by-product vs. fat-rich oil coating) on the fecal microbiota of healthy adult dogs over 90 days. Twenty-four dogs were randomly assigned to control, hempseed by-product (11% inclusion), or hempseed oil (2% coating) diet groups. Fecal samples collected on days 0, 30, and 90 were analyzed using 16S rRNA gene sequencing to assess microbial composition and diversity. The hempseed oil group showed a distinguishable increase in species richness. Both hempseed-based diets were associated with compositional shifts in formulation-specific ways: the oil coating with a higher relative abundance of Lactobacillaceae (notably Ligilactobacillus), and the by-product with a higher relative abundance of Actinobacteriota (particularly Collinsella). Both treatments preserved several microbiota genera. Beta diversity analysis revealed significant temporal restructuring, with convergence toward a stabilized ecosystem by day 90. These findings demonstrate that hempseed fractions modulate the canine microbiome in a formulation-specific manner without disrupting ecological stability, supporting beneficial health effects in canine nutrition.