Effects of a novel dental chew on oral health outcomes, halitosis, and microbiota of adult dogs.

Halitosis in dogs is an initial indication of periodontitis, highlighting its significance as a vital marker for underlying problems. Moreover, the oral microbial population has a significant influence on periodontal disease. Measuring the oral microbiota may be used in addition to breath odor, dental plaque, and gingivitis scoring to assess the impact of dental chews on oral health. In this study, we aimed to determine the differences in breath odor, oral health outcomes, and oral microbiota of adult dogs consuming a novel dental chew compared with control dogs consuming only a diet. Twelve healthy adult female beagle dogs were used in a crossover design study. Treatments (n = 12/group) included: diet only (control) or the diet + a novel dental chew. Each day, one chew was provided 4 h after mealtime. On days 1, 7, 14, 21, and 27, breath samples were analyzed for total volatile sulfur compound concentrations using a halimeter. On day 0 of each period, teeth were cleaned by a veterinary dentist blinded to treatments. Teeth were scored for plaque, calculus, and gingivitis by the same veterinary dentist on day 28 of each period. After scoring, subgingival and supragingival plaque samples were collected for microbiota analysis using Illumina MiSeq. All data were analyzed using SAS (version 9.4) using the Mixed Models procedure, with P < 0.05 being significant. Overall, the dental chews were well accepted. Dogs consuming the dental chews had lower calculus coverage, thickness, and scores, lower gingivitis scores, and less pocket bleeding than control dogs. Breath volatile sulfur compounds were lower in dogs consuming the dental chews. Bacterial alpha-diversity analysis demonstrated that control dogs had higher bacterial richness than dogs fed dental chews. Bacterial beta-diversity analysis demonstrated that samples clustered based on treatment. In subgingival and supragingival plaque, control dogs had higher relative abundances of potentially pathogenic bacteria (Pelistega, Desulfovibrio, Desulfomicrobium, Fretibacterium, Helcococcus, and Treponema) and lower relative abundances of genera associated with oral health (Neisseria, Actinomyces, and Corynebacterium). Our results suggest that the dental chew tested in this study may aid in reducing periodontal disease risk in dogs by beneficially shifting the microbiota population and inhabiting plaque buildup.

In this study, we aimed to determine the effects of a novel dental chew on the breath odor, oral health outcomes, and oral microbiota of dogs. Healthy adult dogs were used in a crossover design study to test a diet only (control) or the diet plus a novel dental chew. Each day, one chew was provided 4 h after mealtime. Breath samples were analyzed over time and teeth were scored for plaque, calculus, and gingivitis by a veterinary dentist on day 28 of each period. After scoring, subgingival and supragingival plaque samples were collected for microbiota analysis. Dogs consuming dental chews had lower calculus coverage, thickness, and scores, lower gingivitis scores, and less pocket bleeding than control dogs. Breath volatile sulfur compounds were lower in dogs consuming dental chews. Bacterial alpha-diversity was higher in control dogs than in dogs fed dental chews. Bacterial beta-diversity analysis demonstrated sample clustering based on treatment. Control dogs had higher relative abundances of potentially pathogenic bacteria and lower relative abundances of genera associated with oral health. Our results suggest that the dental chew tested may aid in reducing periodontal disease risk in dogs by beneficially shifting microbiota and inhabiting plaque buildup.

Heart rate, arterial pressure and propofol-sparing effects of guaifenesin in dogs.

OBJECTIVE: To evaluate the heart rate (HR) and systemic arterial pressure (sAP) effects, and propofol induction dose requirements in healthy dogs administered propofol with or without guaifenesin for the induction of anesthesia. STUDY DESIGN: Prospective blinded crossover experimental study. ANIMALS: A total of 10 healthy adult female Beagle dogs. METHODS: Dogs were premedicated with intravenous (IV) butorphanol (0.4 mg kg-1) and administered guaifenesin 5% at 50 mg kg-1 (treatment G50), 100 mg kg-1 (treatment G100) or saline (treatment saline) IV prior to anesthetic induction with propofol. HR, invasive sAP and respiratory rate (fR) were recorded after butorphanol administration, after guaifenesin administration and after propofol and endotracheal intubation. Propofol doses for intubation were recorded. Repeated measures analysis of variance (anova) was used to determine differences in propofol dose requirements among treatments, and differences in cardiopulmonary values over time and among treatments with p < 0.05 considered statistically significant. RESULTS: Propofol doses (mean ± standard deviation) for treatments saline, G50 and G100 were 3.3 ± 1.0, 2.7 ± 0.7 and 2.1 ± 0.8 mg kg-1, respectively. Propofol administered was significantly lower in treatment G100 than in treatment saline (p = 0.04). In treatments G50 and G100, HR increased following induction of anesthesia and intubation compared with baseline measurements. HR was higher in treatment G100 than in treatments G50 and saline following induction of anesthesia. In all treatments, sAP decreased following intubation compared with baseline values. There were no significant differences in sAP among treatments. fR was lower following intubation than baseline and post co-induction values and did not differ significantly among treatments. CONCLUSIONS AND CLINICAL RELEVANCE: When administered as a co-induction agent in dogs, guaifenesin reduced propofol requirements for tracheal intubation. HR increased and sAP and fR decreased, but mean values remained clinically acceptable.

Connectional Modularity of Top-Down and Bottom-Up Multimodal Inputs to the Lateral Cortex of the Mouse Inferior Colliculus.

The lateral cortex of the inferior colliculus receives information from both auditory and somatosensory structures and is thought to play a role in multisensory integration. Previous studies in the rat have shown that this nucleus contains a series of distinct anatomical modules that stain for GAD-67 as well as other neurochemical markers. In the present study, we sought to better characterize these modules in the mouse inferior colliculus and determine whether the connectivity of other neural structures with the lateral cortex is spatially related to the distribution of these neurochemical modules. Staining for GAD-67 and other markers revealed a single modular network throughout the rostrocaudal extent of the mouse lateral cortex. Somatosensory inputs from the somatosensory cortex and dorsal column nuclei were found to terminate almost exclusively within these modular zones. However, projections from the auditory cortex and central nucleus of the inferior colliculus formed patches that interdigitate with the GAD-67-positive modules. These results suggest that the lateral cortex of the mouse inferior colliculus exhibits connectional as well as neurochemical modularity and may contain multiple segregated processing streams. This finding is discussed in the context of other brain structures in which neuroanatomical and connectional modularity have functional consequences. SIGNIFICANCE STATEMENT: Many brain regions contain subnuclear microarchitectures, such as the matrix-striosome organization of the basal ganglia or the patch-interpatch organization of the visual cortex, that shed light on circuit complexities. In the present study, we demonstrate the presence of one such micro-organization in the rodent inferior colliculus. While this structure is typically viewed as an auditory integration center, its lateral cortex appears to be involved in multisensory operations and receives input from somatosensory brain regions. We show here that the lateral cortex can be further subdivided into multiple processing streams: modular regions, which are targeted by somatosensory inputs, and extramodular zones that receive auditory information.