Healthy Adult Dogs Research Articles

Comparison of the fecal microbiota of adult healthy dogs fed a plant-based (vegan) or an animal-based diet.

Pet guardians are increasingly seeking vegan dog foods. However, research on the impact of these diets on gastrointestinal (GI) physiology and health is limited. In humans, vegan diets modify the GI microbiota, increasing beneficial digestive microorganisms. This study aimed to examine the canine fecal microbiota in response to a vegan diet compared to an animal-based diet. Sixty-one client-owned healthy adult dogs completed a randomized, double-blinded longitudinal study. Dogs were randomly assigned into two groups that were fed either a commercial extruded animal-based diet (MEAT, n = 30) or an experimental extruded vegan diet (PLANT, n = 31) for 12 weeks. Fecal collections occurred at the start of the experimental period and after 3 months of exclusively feeding either diet. Bacterial DNA was extracted from the feces, and the V4 region of the 16S rRNA gene was amplified using PCR and sequenced on Illumina MiSeq. Beta-diversity was measured using Jaccard and Bray-Curtis distances, and the PERMANOVA was used to assess for differences in fecal microbiota within and between groups. Alpha-diversity indices for richness, evenness, and diversity, as well as relative abundance, were calculated and compared between groups. Beta-diversity differences occurred between diet groups at exit time-point with differences on Bray-Curtis distances at the family and genus levels (p = 0.007 and p = 0.001, respectively), and for the Jaccard distance at the family and genus level (p = 0.006 and p = 0.011, respectively). Significant differences in alpha-diversity occurred when comparing the PLANT to the MEAT group at the exit time-point with the PLANT group having a lower evenness (p = 0.012), but no significant differences in richness (p = 0.188), or diversity (p = 0.06). At exit-timepoint, compared to the MEAT group, the relative abundance of Fusobacterium, Bacteroides, and Campylobacter was lower in the PLANT group. The relative abundance of Fusobacterium decreased over time in the PLANT group, while no change was observed in the MEAT group. These results indicate that vegan diets may change the canine gut microbiota. Future studies are warranted to confirm our results and determine long-term effects of vegan diets on the canine gut microbiome.

A dose characterization study evaluating the pharmacodynamics and safety of a concentrated alfaxalone solution (4%) as an intramuscular sedative in dogs.

Alfaxalone is a commonly employed veterinary anaesthetic induction and sedation agent. A 4% w/v preserved, aqueous formulation of alfaxalone 'RD0387' (A4%) has recently been developed. To evaluate the sedative effects of A4%, three doses, 5 mg kg-1 (A5); 7.5 mg kg-1 (A7.5) and 10 mg kg-1 (A10) were administered intramuscularly into the epaxial musculature of six healthy adult mixed-breed dogs in an experimental, randomized, blinded, crossover study. Sedation time variables, quality of sedation (including onset of sedation and recovery), physiological variables, response to cephalic vein catheterization and frequency of undesirable events were recorded. Continuous variables were analysed between treatments (one-way ANOVA or restricted maximum likelihood modelling) and within treatments compared with baseline (Tukey's test). Categorical data were analysed between treatments (Kruskal-Wallis' test) and within treatments from baseline (Dunn's test). Significance was set at p < .05. All dogs became sedated (laterally recumbent) and sedation onset was significantly faster in groups A7.5 (9.8 ± 5.3 min) and A10 (9.1 ± 5.6 min) compared to A5 (25.6 ± 16.1 min) (p = .033, p = .027, respectively). Duration of sedation was significantly longer in A10 (168.5 ± 70.6 min) and A7.5 (143.8 ± 58 min) compared to A5 (63.8 ± 28.2 min) (p = .005 and p = .003, respectively). Dogs in A10 had a superior quality of onset of sedation compared to A5 (p = .028). Sedation scores and quality of recovery from sedation were not significantly different between doses. Two dogs (2/6) in A5 were insufficiently sedated for cephalic catheterization. Ataxia was the most frequently observed undesirable event with an overall frequency of 78% (14/18) and 89% (16/18) during sedation onset and recovery, respectively. Overall, A4% administered IM in dogs at 7.5 and 10 mg kg-1 resulted in sufficient sedation for IV catheterization in dogs. To improve the speed and quality of the sedation, it is recommended that future research focuses on combining A4% with other sedative or analgesic drugs.

RETINAL AGING IN COMPANION DOGS

Abstract Companion dogs cohabit with humans in approximately 45% of US households. They experience similar environmental exposures and lifestyles to their human companions, and have shown sensory, cognitive, and neurological decline with aging. The relationship between age and retinal neurologic function in dogs has not been described. The aim of this study was to determine associations between age and retinal full-field electroretinographic measures in companion dogs, an important translational model species for human neurologic aging. Healthy adult companion dogs with no ophthalmic abnormalities were included (n=54, 18 male, 36 female, median weight 25.7kg, median age 89 months). Unilateral full-field light-adapted and dark-adapted electroretinography (ERG) was performed using a handheld device, with mydriasis and topical anesthesia. Standard least squares effect leverage models were used with log transformed data to determine the cross-sectional effect of age, sex, and bodyweight on ERG amplitudes and peak times. Age and sex were significantly associated with ERG outcome variables, more consistently with ERG amplitude than peak time; age had the largest and most significant effect leverage on outcomes (significantly affecting 3/9 peak time and 8/10 amplitude outcome variables). Younger and female dogs had higher ERG amplitudes. Body weight had no significant effect on any outcome. Our finding that aged companion dogs have reduced ERG amplitudes and prolonged peak times mirror ERG findings in aging humans. Because dogs have a shorter lifespan compared with humans, they may act as a sentinel species to monitor for emerging risk factors for age-related neurologic decline.

Extruded diet macronutrient digestibility: plant-based (vegan) vs. animal-based diets in client-owned healthy adult dogs and the impact of guardian compliance during in-home trials

IntroductionPlant-based (vegan) diets for dogs are commercially available, however, research investigating long-term nutritional adequacy of these diets is scarce. Use of client-owned animals has become increasingly popular for apparent total-tract nutrient digestibility (ATTD) studies, yet low guardian compliance with the study protocol, such as providing daily dietary intake information, is a challenge. However, the impact of low diet reporting compliance on the overall ATTD results is unknown.MethodsSixty-one, client-owned healthy adult dogs completed a randomized, double-blinded longitudinal study. Dogs were randomly assigned into two groups that were fed either a commercial extruded meat-based diet (MEAT, n=30) or an experimental extruded vegan diet (PLANT, n=31) for 12 weeks. At the end of the study, pet guardians performed a 72-hour total fecal collection for ATTD assessment. Pet guardians were asked to complete a food diary for the duration of the trial, however only a subset of guardians (n=35) provided this food diary at the end of the study.ResultsNo evidence of an association between pet guardians providing a food diary and apparent digestibility coefficients (ADC) of crude protein (CP) (p=0.14), crude fat (EE) (p=0.72), and dry matter (DM) (p=0.68) was found. Apparent digestibility coefficients for CP (p=0.52), EE (p=0.78), and DM (p=0.43) did not differ between PLANT and MEAT. Body weight and age were found to be associated with CP (p=0.03) and DM (p=0.01) digestibility, but no association with EE (p=0.07) digestibility was present.DiscussionThese results indicate that vegan- and animal-based diets with similar nutrient profiles can have comparable nutrient digestibility. Moreover, presence or absence of a guardian-reported food diary had no effect on the overall results of the ATTD study. Further studies investigating guardian compliance for ATTD trials are needed to develop a standardized protocol and reduce current challenges and limitations related to pet guardian’s participation in digestibility trials.

Long-term effect of oral cannabidiol administration to healthy adult dogs on tear production, intraocular pressure, and tear concentrations.

To determine the chronic effects of oral cannabidiol (CBD) use on tear production, intraocular pressure (IOP), and concentration of CBD in tears of healthy dogs. Eighteen healthy research Beagles. This was a masked, placebo-controlled, randomized prospective study. Eighteen dogs were randomly assigned to three groups (six dogs per group) based on daily dosage of oral MCT oil (placebo), CBD 5 mg/kg, and CBD 10 mg/kg. Schirmer tear test (STT-1) and IOP were measured twice daily (7 am and 7 pm) every 4 weeks for 36 weeks. Week 36 tears were collected and analyzed for CBD concentrations (ng/mL) using liquid chromatography/mass spectrometry. A mixed linear model was used as the statistical method and p-value <.05 was considered significant. No significant differences were found between placebo vs. 5 mg/kg vs. 10 mg/kg for STT-1 or IOP (AM and PM). CBD was detected in 10 out of 11 (91%) viable tear samples receiving 5 mg/kg or 10 mg/kg dosages. One sample in the 5 mg/kg group had inadequate tear volume for analysis. The CBD concentration in tears was at or below the lower limit of quantification in placebo group, 4.12-11.2 ng/mL for the 5 mg/kg group, and 6.22-152 ng/mL for the 10 mg/kg group. Long-term administration of oral CBD in healthy research beagles demonstrates a favorable safety profile regarding ocular tolerability. Oral CBD administration does not appear to affect tear production or IOP over a 36-week period. This is the first canine study positively identifying concentrations of CBD in tears following oral administration.

Tolerability of long-term cannabidiol supplementation to healthy adult dogs.

Cannabidiol (CBD) has therapeutic potential in companion animals. Shorter-term studies have determined that CBD is well tolerated in dogs with mild adverse effects and an increase in alkaline phosphatase (ALP) activity. There is need to assess CBD's long-term tolerability. Determine the long-term tolerability of CBD administered PO to healthy dogs for 36 weeks at dosages of 5 and 10 mg/kg body weight (BW)/day. Our hypothesis was that CBD would be well tolerated by dogs. Eighteen healthy adult beagle dogs were randomly assigned to 3 groups of 6 each that received 0, 5, or 10 mg/kg BW/day CBD PO. Dogs were adapted to their housing for 3 weeks and received treatment for 36 weeks once daily with food. Adverse events (AEs) were recorded daily. Blood biochemistry profiles were monitored every 4 weeks. Data were analyzed as repeated measures over time using a mixed model, with significance at α = 0.05. The 0 and 5 mg/kg treatment groups had similar fecal scores, and the 10 mg/kg treatment group had higher frequency of soft feces. No other significant AEs were noted. An increase (P < .0001) in ALP activity occurred in groups that received CBD. Remaining blood variables were within reference range. Chronic administration of CBD in healthy dogs at 5 mg/kg was better tolerated than 10 mg/kg, and both dosages caused an increase in ALP activity. Although our data does not indicate hepatic damage, it is recommended to monitor liver function in dogs receiving CBD chronically.

The Perception of the Body Condition of Cats and Dogs by French Pet Owners and the Factors Influencing Underestimation

Managing pet obesity relies heavily on the active involvement of owners; however, a key challenge arises from misperceptions about their own pet’s body condition. Given evolving societal dynamics like the body positivity movement, understanding owners’ perceptions is increasingly pivotal. To evaluate the differences in owners’ perception, this study compared the use of verbal and visual body condition score scales versus the established nine-point body condition score system. The factors linked to underestimation were further specifically investigated. Owners of healthy adult dogs and cats attending vaccination consultations in Veterinary Hospitals in France between 2020 and 2022 were recruited. They were required to assess their pets’ body condition initially using an oral description and then with the nine-point BCS visual scale. Their assessments were then compared with the BCS determined by veterinary health care personnel, considered the primary investigator. A total of 304 dogs and 270 cats were included in the study. It was observed that 27% of dog owners and 24% of cat owners underestimated their pets’ body condition. Among dog and cat owners, factors associated with the underestimation of body condition were the pets’ overweight status and having children. This discovery emphasizes the need for a holistic One Health approach that prioritizes the health and well-being of both humans and their pets. When it comes to pet owners evaluating their pets’ body condition, underestimation proved to be the predominant misperception. Addressing this issue requires comprehensive education to empower owners to recognize and comprehend their pets’ overweight status, a critical step for the overall well-being of companion animals.

Abstract 18729: cBIN1 Gene Therapy Improves Recovery of Peri-Infarction Muscle in a Canine Model of Chronic Ischemic Heart Failure

BACKGROUND: Heart failure (HF) due to ischemic dilated cardiomyopathy (IDCM) is a major cause of morbidity and mortality. In failing hearts, loss of T-tubule microdomains is central to impaired calcium transients and loss of cardiac function. Cardiac bridging integrator 1 (cBIN1), a membrane scaffolding protein that organizes T-tubule microdomains, is transcriptionally reduced in failing hearts. Hypothesis: cBIN1 gene therapy will improve cardiac function in ischemic cardiomyopathy. AIM: Evaluate the effectiveness of catheter-based delivery of cBIN1 gene therapy in preserving bipolar voltage (an assay of muscle health) and LVEF in a canine model of IDCM. Methods: Nine healthy adult mongrel dogs (30±3 kg) underwent LAD ligation, developing IDCM and HFrEF (LVEF &lt; 40% and NT-proBNP &gt;900 pmol/L) over 3-4 months. Animals received a single treatment at 20 sites by intramyocardial injection of either AAV9-GFP (control, n=3) or AAV9-cBIN1 (n=6) using a MyoStar catheter-mediated subendocardial injection. Low voltage LV regions were quantified as percent of total endocardial area with bipolar voltage &lt;1.5 mV on the day of the treatment (pre-therapy) and the terminal study (5-10 weeks post-therapy). Results: In control-treated dogs, low voltage areas did not change significantly (19.5±3.4 vs. 28.7±9.8%, p=0.143, Figure A ), whereas in the cBIN1-treated cohort, the low voltage areas surrounding infarction zones decreased significantly (18.9±10.9 vs. 13.4±9.1%, p=0.038, Figure B ). Control therapy was associated with an additional 9.2% loss LV myocardium, whereas cBIN1 therapy caused a 6.5% recovery of myocardium (p=0.024, Figure C ). Post-therapy week 5, LVEF decreased in control animals (36±2 vs. 29±3%, p&lt;0.001) yet improved in the cBIN1-treated animals (37±2 vs. 41±3%, P=0.003). CONCLUSION: Intramyocardial injection of cBIN1 gene therapy can halt and reverse expansion of peri-infarction low voltage areas and improve LVEF in a preclinical IDCM model of chronic HF.

200 The Effects of Whole Hemp Seed Supplementation on Health Status, Voluntary Physical Activity, Fecal Quality, and Fermentative End-Products in Healthy Adult Dogs

Abstract The cultivation and utilization of hemp and hemp-derived products have increased at a rapid pace since the enactment of the 2018 farm bill which provided changes in regulation related to cannabis. Although there are three hemp-derived ingredients that have been generally recognized as safe status for human consumption by the FDA, no ingredients have been approved by the FDA for consumption by companion animals or defined by AAFCO. Hemp seeds have the potential to act as a rich source of plant protein, polyunsaturated fatty-acids, and dietary fiber in companion animal nutrition. The objective of this study was to evaluate the effects of supplementing ground whole hemp seed in a baked chew on voluntary physical activity, fecal characteristics, fermentative-end products, and overall health status in healthy adult dogs. All animal procedures were approved by the University of Illinois Institutional Animal Care and Use Committee and were in accordance with the United States Public Health Service Policy on Humane Care and Use of Laboratory Animals. Thirty adult beagle dogs were used in a complete randomized design, with ten dogs assigned to each treatment. The dogs were fed the same commercially available, complete and balanced diet and were supplemented with one of three baked chews containing either a high inclusion of ground hemp seed (50%), a low inclusion of ground hemp seed (25%), or cellulose. The baked chews were fed at a level of 10% of the daily intake for 28 d and were formulated to be similar in macronutrient composition, approximately 25% fat, 20% protein, and 25% total dietary fiber. Duration and intensity of voluntary physical activity was measured using activity monitors for 4 d before supplementation and at the end of the supplementation period (d 24 to 27). Fasted blood and a fresh fecal sample were taken on d 0, 14, and 28 to monitor health status, blood variables, fecal characteristics and fermentative-end product concentrations. The baked chews were well accepted by the dogs with minimal intake refusals, and all dogs remained clinically healthy for the duration of the experimental period. No differences in fecal score or fecal pH were observed among the treatment groups (P &amp;gt; 0.05). The treatment did not have an effect on fecal concentrations of volatile fatty acids including acetate, propionate, butyrate, valerate, isovalerate, and isobutyrate (P &amp;gt; 0.05). Concentrations of fecal ammonia, phenols, and indoles were also similar among the groups (P &amp;gt; 0.05). No adverse effects were observed, and the data suggest that in a baked chew the whole ground hemp seed was comparable to the cellulose control.

PSVIII-17 In-Home Validation of a Canine Supplement Containing a Saccharomyces Cerevisiae Fermentation Product

Abstract Controlled, evidence-based research studies are essential to ensure functional pet food, treat and supplement ingredients are efficacious. However, understanding how nutritional technologies influence pet health and well-being in the pet's home environment is an additional way to derive further insight on performance and effectiveness. Therefore, the objective of this study was to assess the efficacy of supplemental Saccharomyces cerevisiae fermentation product (SCFP) using subjective pet owner insights coupled with an analysis of fecal metagenomic characteristics in dogs using an in-home testing approach. Healthy adult dogs (n = 348; 170 males and 178 females; mean age = 6.0 y; mean BW = 18.2 kg) were recruited from across the U.S. and randomly allotted to one of two treatment groups blocked by breed, gender, age and BW. Owners were asked to feed their dogs their usual food, treats and supplements throughout the 60-d study. The SCFP was delivered in a daily chew. The control was a placebo chew void of SCFP (CON), and the treatment chew (EPI) was formulated to deliver 7 mg· kg BW-1· d-1 SCFP (EpiCor postbiotic, Ankeny, IA). Surveys were fielded on d 0, 15, 30, 45 and 60 to obtain pet owner subjective ratings of supplement performance across key health attributes. Fecal sample collection kits were provided to respondents on d 0, 30 and 60 for shotgun metagenomic analysis. All statistical analyses were conducted in R v.4.1.2. Ordinal logistic regression using the package ordinal in R was conducted on the survey data to understand relationships between the predictor variables and the ranked outcomes. Metagenomic data were analyzed using phyloseq, vegan, lme4, LinDA and emmeans packages in R. Differences P &amp;lt; 0.05 were considered significant and P ≤ 0.10 as trends after FDR correction. Dogs receiving the EPI chew received numerically higher immunity ratings throughout the study and overall tended to be 95% more likely (P = 0.10) to receive a higher immune health rating versus CON. By d 60, EPI dogs were more likely (211% greater odds; P = 0.007) to exhibit less breath odor and 165% more likely to be less anxious (P = 0.02) than CON dogs. An increased relative abundance in butyrate producing taxa Anaerostipes hadrus (P = 0.002) and Megamonas (P = 0.001) and Fusobacteria (P = 0.004) were observed in EPI dogs emerging at d 30. Under the conditions of this study, daily supplementation of a SCFP supplement provided a spectrum of positive health outcomes in healthy adult dogs. Moreover, there was consistency in physiological benefits noted in previous controlled studies in healthy dogs fed SCFP to the owner-perceived changes in several health attributes in this study. Our data also suggest that SCFP may beneficially affect key indicators of breath odor and anxiety in dogs.

202 Functional Properties of Ganoderma Lucidum (GL) Supplementation in Canine Nutrition

Abstract Ganoderma lucidum (GL) is a mushroom that has been widely used in Asia for its immunomodulatory and anti-inflammatory capacity. However, the nutraceutical properties of GL have not been tested in dogs. Forty adult beagles were used in a completely randomized design. Dogs were fed a commercial dry extruded complete and balanced diet plus GL top-dressed daily upon feeding time. Four experimental treatments were used: 0% GL supplementation (control), 5 mg/ kg BW of GL, 10 mg/ kg BW of GL, or 15 mg/kg BW of GL. Following a 7-d adaptation to the control diet, dogs were fed their respective treatment diets for 28 d. They were challenged with vaccination of a modified live virus Canine Distemper, Adenovirus Type 1 (Hepatitis), Adenovirus Type 2, Parainfluenza, and Parvovirus and killed Rabies Virus on d 7 with blood collections on d 0, 14, and 28. The objective of the present study was to evaluate the effects of dietary inclusion of GL on vaccine-specific serum immunoglobulin G (IgG) and fecal microbiota. The vaccine-specific serum IgG concentrations, following vaccination for rabies, in adult dogs fed 15 mg/kg of GL were greater (P = 0.0384) than the group control when analyzed as a fold change from baseline. The predominant phyla that comprised the fecal microbial community of the dogs in all groups were Bacteroidetes, Firmicutes, and Fusobacteriota. At the class level, Bacilli, Bacteroidia, Clostridia, Fusobacteriia, and Negativicutes had greater relative abundance. The α and β diversities of fecal microbial communities were not impacted by treatment. These data suggest that the inclusion of GL had no detrimental effects on fecal microbiota. And due to impact in vaccine response among treatments, GL may exert beneficial immunomodulatory effects in healthy adult dogs when provided at a daily dose of 15 mg/ kg BW.

PSVIII-21 A Premium Dry Dog Food Elicits Gut Health Benefits Compared with a Grocery Dry Dog Food

Abstract With the pet humanization trend, pet parents are continuously seeking approaches to improve the health of their pets. Compared with grocery dog foods produced to meet the basic needs of the dog, premium dog foods include high-quality ingredients and functional benefits that can be more appealing to consumers. However, little research is available comparing health measures in dogs fed premium foods vs. basic grocery foods. The objective of this study was to compare the effects of feeding a premium dog kibble diet (Blue Buffalo; BB) and a grocery dog kibble diet on digestibility, blood biomarkers, and fecal microbiome in healthy adult dogs. Sixty dogs (mean BW = 10.8 ± 2.0 kg; mean age = 8.2 ± 3.3 yr) were randomly selected to consume BB (n = 30) or the grocery diet (n = 30) for 180 days. On days 0, 90, and 180, fresh fecal samples were collected for fecal microbiome and dysbiosis index analysis and blood samples were collected for measurements of complete blood count, serum chemistry, and serum biomarkers. A separate 10-day digestibility study was conducted using 12 dogs (BB n = 6, grocery diet n = 6; mean BW = 12.0 ± 2.1 kg). Total fecal samples were collected from day 6 to day 10 for nutrient digestibility analysis. Protocols were approved by the facility’s Institutional Animal Care and Use Committee before the study. All data were analyzed using the Mixed Models procedure of SAS. Stool quality was not different (P &amp;gt; 0.05) between diet groups. Both diets were highly digestible without dietary effects (P &amp;gt; 0.05). All blood cell count and serum chemistry values were within the reference ranges. However, dogs fed the grocery diet had greater (P &amp;lt; 0.05) liver enzyme concentrations including alanine transaminase, alkaline phosphatase, and gamma-glutamyl transpeptidase, and greater (P &amp;lt; 0.05) monocyte counts compared with BB. Dogs had greater (P &amp;lt; 0.05) serum pancreatic polypeptide when fed BB. A lower dysbiosis index (less dysbiotic microbiome) was observed in dogs consuming BB. Relative abundances of 23 bacterial genera were altered (P &amp;lt; 0.05) by the diets, with greater abundances of Bifidobacterium and Megamonas and decreased abundance of Streptococcus observed in the BB group compared with the grocery diet group. These results suggest that premium dry dog food could potentially elicit a positive impact on blood parameters and GI health.

196 The Effect of Hydrolyzed Protein on Fecal Microbiota in Adult Dogs

Abstract Research on protein hydrolysates has observed various properties and functionalities of these ingredients depending on the type of hydrolysate. The objective of this study was to evaluate the effect of hydrolyzed chicken protein that was incorporated into diets on gut health in healthy adult dogs. Five complete and balanced treatment diets were manufactured: 1) CONd: chicken meal diet; 2) 5% CLHd: 5% substitution of chicken liver hydrolysate of chicken meal diet; 3) CLHd: chicken liver hydrolysate diet; 4) 5% CHd: 5% substitution of chicken hydrolysate of chicken meal diet; and 5) CHd: chicken hydrolysate diet. A 5×5 Latin square design was used which included 10 neutered adult beagles. Each of the 5 periods consisted of a 7-d washout time and a 28-d treatment period. All diets were well accepted by the dogs. For fecal metabolites, there was greater fecal butyrate concentration as well as reduced isovalerate, 4-ethylphenol, and indole in dogs fed CLHd than CONd (P &amp;lt; 0.05). Regarding the overall microbiota composition, Firmicutes, Bacteriodota, Fusobacteriota, Actinobacteriota, and Proteobacteria were the top 5 most abundant phyla. At the class level, samples from CHd group had greater relative abundances of Bacteriodia and Fusobacteriia as well as less Bacilli. On the other hand, CLHd group had greater abundances of Bacilli and Actinobacteria with less Fusobacteriia. At the level of order, CHd group had greater Bacteriodales and Fusobacteriales while CLHd group had greater Bifidobacteriales. At the family level, CHd group showed a greater abundance of Muribaculaceae and a decreased abundance of Bifidobacteriaceae when compared with the other groups. Alternatively, CLHd group demonstrated a greater abundance of Bifidobacteriaceae together with reduced abundance of Fusobacteriaceae, Muribaculaceae, Sutterrellaceae, and Ruminococcaceae. Fecal microbiota was shifted by CLHd with greater differential abundance in Ruminococcus gauvreauii group as well as reduced Clostridium sensu stricto 1, Sutterella, Fusobacterium, and Bacteroides compared with CONd (P &amp;lt; 0.05). There was also a difference in beta diversity of fecal microbiota between CLHd and CHd (P &amp;lt; 0.05). However, no difference was observed in alpha diversity among treatment groups (P &amp;lt; 0.05). Fecal butyrate concentration was negatively correlated with the genera Blautia, Phascolarctobacterium, Sutterella, Faecalibacterium, and Bacteriodes. Conversely, Allobaculum and Bifidobacterium were positively correlated with butyrate concentration. In conclusion, the test chicken protein hydrolysates may have potential to support gut health by modulating microbiota.

PSIX-6 The Effects of Hydrolyzed Protein on Macronutrient Digestibility, Fecal Metabolites, Oxidative Stress and Inflammatory Biomarkers, and Skin and Coat Quality in Adult Dogs

Abstract Research on protein hydrolysates has observed various properties and functionalities of these ingredients depending on the type of hydrolysate. The objective of this study was to evaluate the effects of hydrolyzed chicken protein that was incorporated into diets on digestibility, gut health, skin and coat health, oxidative stress, and inflammation in healthy adult dogs. Five complete and balanced treatment diets were manufactured: 1) CONd: chicken meal diet; 2) 5% CLHd: 5% substitution of chicken liver hydrolysate of chicken meal diet; 3) CLHd: chicken liver hydrolysate diet; 4) 5% CHd: 5% substitution of chicken hydrolysate of chicken meal diet; and 5) CHd: chicken hydrolysate diet. A 5×5 Latin square design was used which included 10 neutered adult beagles. Each of the 5 periods consisted of a 7-d washout time and a 28-d treatment period. All diets were well accepted by the dogs. There was greater (P &amp;lt; 0.05) fecal butyrate (226.8 μmol/g DMB) concentration as well as decreasedr isovalerate (6.8 μmol/g DMB), 4-ethylphenol (1.4 μmol/g DMB), and indole (0.7 μmol/g DMB) in dogs fed CLHd than CONd (149.3, 10.8, 2.5, and 1.5 μmol/g DMB, respectively). Doges fed CHd had greater (P &amp;lt; 0.05) fecal immunoglobulin A concentration (2.86 mg/g) when compared with CLHd (0.91 mg/g); however, both groups were comparable to the control. There was no difference among groups in serum cytokine concentrations, serum oxidative stress biomarkers, or skin and coat health analyses (P &amp;gt; 0.05). In conclusion, chicken protein hydrolysate could be incorporated into canine extruded diets as a comparable source of protein to traditional chicken meal. The test chicken protein hydrolysates may have potential to support gut health by modulating immune response and fermentative activity; however, more research is needed to confirm the effect.

193 Apparent Total Tract Nutrient Digestibility of Frozen Raw, Freeze-Dried Raw, Fresh, and Extruded Dog Foods and Their Effects on Fecal Characteristics and Metabolites of Adult Dogs

Abstract Various pet food diet formats are now available. Processing methods are known to impact nutrient digestibility and are thought to affect pet health but are poorly studied. Therefore, the objective of this study was to determine the apparent total tract macronutrient digestibility (ATTD) of frozen raw, freeze-dried raw, fresh, and extruded dog foods and assess their effects on fecal characteristics, and fecal metabolites of healthy adult dogs. Ten healthy adult spayed female dogs were used in a replicated 5x5 Latin square study to test the following diets: Chicken and Barley Recipe [extruded diet; Hill’s Science Diet (EXT)], Chicken and White Rice Recipe [fresh diet; Just Food for Dogs (FRSH)], Chicken Formula [raw frozen diet; Primal (FRZN)], Chicken and Sorghum Hybrid Freeze-dried Formula [hybrid freeze-dried raw diet; Primal (HFD)], and Chicken Dinner Patties [raw freeze-dried diet; Stella &amp; Chewy (FD)]. The experiment was composed of five 35-day periods. Total feces excreted during a 5-day total collection phase was frozen until analyses and ATTD calculations. On the first day of fecal collections, one fresh fecal sample was collected for measurement of pH, dry matter (DM) content, and bile acid (BA) and fermentative metabolite concentrations. Data were analyzed statistically by Mixed Models using SAS 9.4, with P &amp;lt; 0.05 being significant. Widespread differences were noted among diets. Wet and DM fecal output was greater for EXT than other diets, and wet fecal output was greater for FRSH than FRZN, HFD, and FD. Protein ATTD was greater for FRZN and FD than other diets, and greater for HFD than FRSH and EXT. Fat ATTD was greater for HFD than FRZN and EXT, and less for EXT than other diets. Fecal pH was less in EXT and FRSH than other diets. Fecal scores were greater (looser) in EXT and FRSH than FRZN and FRZDR. Fecal DM% was greater in FD than other diets, and greater in FRZN and HFD than EXT and FRSH. In general, fecal short-chain fatty acids were highest in EXT, intermediate in FRSH and HFD, and least in FRZN and FD. Fecal branched-chain fatty acids were greatest in FDF, intermediate in EXT, FRZN, and FD, and least for FRSH. Fecal phenols and indoles were greatest in HYB and least in FRSH, with others being intermediate. Fecal primary BA were greater in FRSH than other diets, while fecal secondary BA were greater in FRZN than HFD, FRSH, and EXT, greater in FD than FRSH and EXT, and greater in HFD than FRSH. In summary, the diets tested were very different in regard to nutrient digestibility, fecal characteristics, and fecal metabolites. More research is necessary to distinguish how ingredient source, diet processing, macronutrient composition, and other factors may contribute to these differences.

199 Effects of Dietary Fiber and Biotic Supplementation on Apparent Total Tract Macronutrient Digestibility, Fecal Characteristics, and Fecal Metabolites of Healthy Adult Dogs

Abstract Synbiotics, or mixtures of live microorganisms and substrates selectively utilized by host microorganisms, may confer complementary or synergistic health benefits to the host. Although synbiotics have demonstrated the potential to modulate the gut microbiome and improve gastrointestinal health in many host species, research trials in companion animal diets are limited. Therefore, this study was conducted to determine the apparent total tract macronutrient digestibility (ATTD) of diets supplemented with fibers or biotics and to evaluate their effects on the fecal characteristics, metabolites, microbiota, and immunoglobulin (Ig) A concentrations of dogs consuming them. Healthy adult female beagles (n = 12; age= 6.2 ± 1.6 yr; BW = 9.5 ± 1.1 kg) were used in a replicated 3 x 3 Latin square design to test three dietary treatments: 1) basal diet based on rice, chicken meal, tapioca starch, and cellulose and without probiotics or prebiotics + a placebo treat (control, CT); 2) diet based on rice, chicken meal, garbanzo beans, and cellulose + placebo treat (GB); 3) diet based on rice, chicken meal, and garbanzo beans, and functional fiber/prebiotic blend (mannanoligosaccharides; fructooligosaccharides, inulin, pea fiber, alfalfa meal, Saccharomyces cerevisiae fermentation product) + probiotic-containing treat (synbiotic treatment, SYN). The probiotic treat contained Bacillus subtilus and Bacillus amyloliquefaciens (2 x 109 CFU/d). In each 28-day period, a 22-day diet adaptation was followed by a 5-day fecal collection phase for measurement of ATTD and fecal characteristics, metabolites, microbiota, and IgA concentrations. Fasted blood samples were collected on day 28 for serum chemistry and complete blood count. All data were analyzed using the Mixed Models procedure of SAS 9.4, with P &amp;lt; 0.05 being significant. ATTD of dry matter (DM), organic matter, and energy were less and DM fecal output was greater in dogs fed SYN than those fed CT or GB, whereas ATTD of crude protein was greater in dogs fed CT and SYN than those fed GB. ATTD of fat was higher and wet fecal output was less in dogs fed CT than those fed GB or SYN. Fecal DM% was greater in dogs fed CT than those fed SYN or GB, and greater in dogs fed SYN than those fed GB. Fecal short-chain fatty acids (SCFA; acetate, propionate, total SCFA) were higher in dogs fed GB than those fed CT or SYN, and higher in dogs fed GB than those fed SYN. Fecal IgA concentrations were greater in dogs fed GB than those fed CT. Serum triglycerides were less in dogs fed GB than those fed SYN or CT. Our results demonstrate that legume-based dietary fibers, with or without prebiotics and probiotics, slightly reduce nutrient digestibility, increase stool output, beneficially shift fecal metabolites, and reduce blood lipids of adult dogs.

PSVIII-13 Evaluating the Effects of a Dried brewer’s Yeast Product on the Fecal Characteristics, Metabolites, and Microbiota Populations of Adult Dogs

Abstract Inclusion of brewer’s yeast in pet foods has become popular because of the potential health benefits it provides. However, more research is needed to evaluate the effects of different brewer’s yeast products on canine gut health outcomes. This study aimed to investigate the effects of a brewer’s yeast product on the fecal characteristics, metabolites, and microbiota populations of adult dogs. Sixteen healthy adult dogs (BW: 9.0 ± 1.7 kg) were acclimated for 7 days and then randomly assigned to a control diet containing no yeast or a brewer’s yeast-containing diet (n = 8/group) for a 21-day period. Fresh fecal samples were collected before and after treatment for measurement of fecal scores, pH, dry matter content, metabolite concentrations [short-chain fatty acids (SCFA), branched-chain fatty acids (BCFA), ammonia, phenols, indoles], and microbiota populations. All data were analyzed as a percent change from baseline using the PROC MIXED procedure of SAS, with treatment as the main effect and dog as a random effect. Significance was declared at P ≤ 0.05, and trends reported if 0.05 &amp;lt; P ≤ 0.10. The brewer’s yeast treatment tended to increase (P = 0.10) fecal butyrate concentrations more than that of controls, but fecal characteristics (pH; dry matter; fecal scores) and other metabolite concentrations were not affected by treatment. Fecal bacterial alpha diversity metrics were not affected by treatment, but beta diversity analysis (unweighted UniFrac distances) tended (P = 0.09) to show a shift between treatments. Change in relative abundance of fecal Blautia was less (P = 0.05) in dogs fed brewer’s yeast than controls, but other bacterial genera were unaffected by diet. In conclusion, this study suggests that the dried brewer's yeast products tested had little impact on fecal characteristics, metabolites, or microbiota populations of adult dogs. The tendency of greater fecal butyrate concentrations in dogs fed brewer’s yeast is encouraging, but further research is needed to identify the potential health benefits of these products in canine diets.

PSIX-3 A Veterinary Gastrointestinal Low-Fat Diet Affects Fecal Characteristics, Metabolites, Bile Acids, and Microbiota Concentrations of Antibiotic-Treated Dogs

Abstract In a recent dog study, the antibiotic metronidazole proved to be an effective disruptor of the fecal microbiota and resulted in looser stools and altered fecal bile acid (BA) profiles. Recovery took several weeks and was aided by a dietary supplement. The objective of this study was to determine how a veterinary gastrointestinal low-fat diet affected the fecal characteristics and metabolite, BA, and microbiota concentrations of dogs recovering from metronidazole administration. Twenty-four healthy adult dogs were used in an 8-wk completely randomized design study. The study began with a 2-wk baseline phase where all dogs consumed a leading grocery brand dry kibble diet (GBD; wk 0 to wk 2). Over the next 2 wk, dogs continued to consume GBD and received metronidazole (20 mg/kg BW; wk 2 to wk 4). At wk 4, dogs were randomly allotted to one of two treatments [GBD; Blue Buffalo Gastrointestinal Support Low-Fat (BB)] for the remaining 4 wk (wk 5 to wk 8). Fecal scores were recorded daily, and fresh fecal samples were collected at wk 2, 4, 5, 6, 7, and 8 for measurement of pH, dry matter, and metabolite and bile acid concentrations. Fecal microbiota populations were also analyzed by 16S rRNA sequencing and qPCR, which was used to calculate dysbiosis index. All data were analyzed as repeated measures using the Mixed Models procedure of SAS 9.4, with treatment treated as a fixed effect, dog as a random effect, and significance set at P &amp;lt; 0.05. As anticipated, metronidazole administration increased (P &amp;lt; 0.0001) fecal scores (looser stools) and drastically altered (P &amp;lt; 0.05) fecal metabolite concentrations, reducing fecal short-chain fatty acid (SCFA), branched-chain fatty acid (BCFA), phenol, and indole concentrations, increasing primary BA concentrations, and decreasing secondary bile acid concentrations. Metronidazole dramatically impacted fecal microbiota populations by reducing alpha diversity, altering the abundance of multiple bacterial taxa, and increasing dysbiosis index. Fecal outcome variables recovered over the next 4 wk, with some being impacted by diet. The change in fecal SCFA and immunoglobulin A concentrations were greater (P &amp;lt; 0.01), while the change in fecal BCFA, phenol, and indole concentrations were decreased (P &amp;lt; 0.05) in dogs fed BB. Dysbiosis index and alpha diversity measures recovered quickly for all dogs and without dietary effects. Recovery of over 25 bacterial genera were impacted by diet (P &amp;lt; 0.05). While many bacterial taxa returned to baseline levels after 4 wk, others had still not fully recovered. Fecal BA concentrations recovered quickly for all dogs. The change in lithocholic acid concentration was less (P &amp;lt; 0.0001) in dogs fed BB, but other BA concentrations were not affected by diet. In conclusion, metronidazole drastically alters the fecal microbiota and metabolites of dogs. While most variables return to normal over time, a veterinary gastrointestinal diet may aid in the recovery.

A comparison of the motor effects and analgesic efficacy following lumbar plexus block combined with sciatic nerve block or epidural in dogs undergoing tibial plateau leveling osteotomy

ObjectiveTo compare motor effects and analgesic efficacy following an ultrasound-guided lateral approach to lumbar plexus blockade at L7 and sciatic nerve blockade (LPSNB) against epidural injection in dogs undergoing tibial plateau leveling osteotomy (TPLO). Study designProspective, randomized, blinded clinical trial. AnimalsA total of 27 healthy adult dogs undergoing unilateral TPLO surgery. MethodsDogs were allocated to either LPSNB (bupivacaine 2 mg kg–1, 0.75%) or epidural (morphine PF 0.1 mg kg–1 and bupivacaine 0.5 mg kg–1, 0.75%). Other aspects of clinical management were identical, including anesthetic drug protocol, area of presurgical clipping and bladder care. Time to perform the block, response to surgical stimuli, pain scores, rescue analgesia, time to stand and walk, motor score and time to first urination were recorded. One evaluator, unaware of treatment status, performed all evaluations. Student’s t-test or Mann–Whitney U test was used to compare continuous variables between groups, and Fisher’s exact test for categorical variables. ResultsMedian (range) times to stand and walk were shorter for LPSNB [60 (40–120) minutes and 90 (60–150) minutes, respectively, p = 0.003] than for epidural [150 (120–240) minutes and 180 (120–360) minutes, respectively, p = 0.006]. Four dogs required rescue intraoperatively (three in epidural group, one in LPSNB group, p = 0.438). Pain scores over the 24 hour evaluation period were similar, and not significantly different, for each group. Time to spontaneous urination [LPSNB, 330 (240–360) minutes; epidural, 300 (120–1440) minutes, p = 1.0] did not differ between groups. Conclusions and clinical relevanceAn ultrasound-guided lateral paravertebral approach to the lumbar plexus within the psoas compartment at L7, combined with sciatic nerve blockade, allows faster return to normal motor function, with similar pain control and impact on urination when compared with epidural in dogs after TPLO surgery.

Electrocardiographic changes and changes in cardiac lactate and troponin I levels associated with search and rescue physical activity in military dogs

Rescue and recovery dogs intercalate the activity intensity developed, which also triggers significant metabolic changes in cardiac physiology. Thus, we evaluated the changes that search simulation causes in glucose, lactate, and cardiac troponin I level (cTnI) and the electrocardiographic and heart rate during the activity and recovery phase to predict the physiological adaptation to the exercise. Five healthy adult dogs from the Rescue and Recovery Service of Military Firefighters Corps were submitted to 60 minutes search operation simulation in the woods. They covered a forest area of approximately 50,000 m2. The dogs were loose and accompanied by their driver, and they could perform any physical activity. Were evaluated serum biochemical analysis of glucose, lactate, cardiac troponin I, electrocardiographic, and heart rate (rest, exercise phase, and recovery time). No changes in glucose levels, heart rate, and cardiac rhythm were detected. In comparison to baseline values, there is an increase: in lactate at the end of the exercise phase [EXER] (60’EXER), and in the recovery phase [RCT] at 30’RCT and 60’RCT, and cTnI at 60’RCT, 120’RCT, and 4hRCT. P wave duration was significantly higher at 60’EXER, 15’RCT, and 30’RCT, with no alterations in wave amplitude. QRS interval duration significantly increased at 30’RCT, and the ST segment presented a significant difference at 60’EXER, 15’RCT, and 60’RCT compared to the rest moment. The moderate alterations in lactate and cTnI and few alterations in the electrocardiographic and heart rate maintenance suggest the adaptation of rescue and recovery dogs to the type, intensity, and duration of search operation simulation performed.