Processing of corn-based dog foods through pelleting, baking and extrusion and their effect on apparent total tract digestibility and colonic health of adult dogs.

Different food processing parameters may alter starch granule structure and its cooking degree. With lower thermomechanical energy, more resistant starch (RS) is retained in the food, which may benefit gastrointestinal (GI) health. The objective of this study was to determine the effect of food processing on dietary utilization and dog gut health. Experimental diets containing 56% corn as the sole starch source were produced through pelleting, baking, and extrusion and compared to a baked control diet in which the corn was replaced with dextrose. The extruded diet resulted in the highest level (P < 0.05) of in vitro starch cook and lowest RS, while baked was intermediate and pelleted had the lowest starch cook and highest RS. To evaluate the in vivo effects of these treatments, 12 dogs were adapted to foods for 9 d, and feces were collected for 5 d in a replicated 4 × 4 Latin square design. Feces were scored for consistency using an ordinal scale, and parametric data included apparent digestibility (ATTD), parameters indicative of gut health, and the microbial composition, which was centered log-ratio transformed before operational taxonomic unit (OTU) analyses. Fecal scores were analyzed by ordinal logistic regression, and parametric data were analyzed as mixed models. Overall ATTD was greater (P < 0.05) in extruded, followed by baked and pelleted. Dogs fed the control had osmotic diarrhea, whereas dogs fed the other treatments had mostly acceptable fecal scores, with extrusion leading to the best fecal quality. The control also led to high fecal pH and low SCFAs, indicating dysbiosis. All corn foods had similar (P > 0.05) fecal SCFAs and extruded tended (P = 0.055) to promote higher fecal butyrate than baked and pelleted. The microbiome of dogs fed the corn foods had similar α diversity indices, and OTUs at the species and phyla levels were mostly alike and different from the control. In conclusion, the higher levels of in vitro RS did not translate into a better in vivo fermentation profile, and extruded kibble performed best regarding fecal quality, ATTD, and fecal SCFAs.

Dog foods were produced via extrusion, baking, and pelleting to yield increasing amounts of starch resistant to digestion (resistant starch [RS]). The foods were compared to a negative dextrose control that contained dextrose in place of starch. Amounts of cooked starch and RS were confirmed by in vitro methodologies. These foods were fed to healthy adult dogs in a Latin square design. Feces were scored for quality and collected to calculate apparent digestibility. Fresh feces were also collected for fecal short-chain fatty acids and microbiome evaluations. The corn-based extruded kibble was more digestible, followed by the baked and pelleted treatments. The extruded treatment produced stools closest to the ideal, but dogs fed the pelleted and baked also produced acceptable feces. The SCFA composition in the feces of dogs fed extruded was like the pelleted treatment, with a higher tendency to produce butyrate. Changes in fermentation were not a consequence of differences in microbiome composition among dogs fed corn-based foods. Dogs fed the control had osmotic diarrhea, with a higher fecal pH and higher proportions of branched-chain fatty acids, which was undesirable. The extruded food performed better overall than baked and pelleted, but they were all acceptable as food forms for dogs.

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

BACKGROUND: 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. HYPOTHESIS: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS AND CLINICAL IMPORTANCE: 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 efficacy and safety of cannabidiol as adjunct treatment for drug-resistant idiopathic epilepsy in 51 dogs: A double-blinded crossover study.

BACKGROUND: Approximately 30% of dogs with idiopathic epilepsy (IE) are drug-resistant. Recent studies have suggested cannabidiol (CBD) may be an effective anticonvulsant in dogs with IE. OBJECTIVE: To evaluate the addition of CBD to antiseizure drugs (ASDs) on seizure frequency and to report adverse events in dogs with drug-resistant IE. ANIMALS: Fifty-one dogs. Dogs having at least 2 seizures per month while receiving at least 1 ASD were included in the trial. METHODS: Double-blinded placebo-controlled crossover study. The 5 mg/kg/day dosage met futility requirements after 12 dogs, and a dosage of 9 mg/kg/day was used in the next 39 dogs. Dogs were randomly assigned to receive CBD or placebo for 3 months, with a 1-month washout period between oils. Total numbers of seizures and seizure days were recorded. Diagnostic testing was performed periodically throughout the trial. RESULTS: At the 9 mg/kg/day dose, the decrease in total seizure frequency was significant compared with placebo. A 24.1% decrease in seizure days occurred in dogs receiving CBD and a 5.8% increase occurred in dogs receiving placebo (P ≤ .05). No significant difference was found in the number of responders (≥50% decrease in total seizures or seizure days). Liver enzyme activities increased at both dosages. Decreased appetite and vomiting were more common in the CBD phase (P ≤ .05). CONCLUSIONS AND CLINICAL IMPORTANCE: Cannabidiol decreased total seizures and seizure days compared to placebo when administered to dogs PO at 9 mg/kg/day. Liver enzymes should be monitored with administration of CBD in dogs.

Cannabidiol plasma determination and pharmacokinetics conducted at beginning, middle and end of long-term supplementation of a broad-spectrum hemp oil to healthy adult dogs.

Introduction: Veterinary hemp products containing cannabidiol (CBD) and negligible psychoactive (THC) have increased popularity since hemp (with <0.3% THC) was removed from schedule 1 substances under the Controlled Substances Act in 2018. This was accompanied by increased CBD research, mostly on the short-term safety and efficacy for inflammatory and neurological conditions. It is imperative to understand how CBD is metabolized or accumulated in the body long-term, thus the goal of the present work was to determine monthly plasma CBD concentrations, as well as changes in pharmacokinetic (PK) parameters in chronically dosed dogs. Methods: The study was a masked, placebo-controlled, randomized design. Six adult beagles were assigned to placebo, 5 and 10 mg/kg/day CBD treatment groups. Dogs received oral oil treatment once daily for 36 weeks. Blood was collected once every 4 weeks pre- and postprandially for CBD plasma determination (at 0 and 2 h). Pharmacokinetics were conducted at 0, 18 and 36 weeks. Pharmacokinetics and monthly CBD plasma data of dogs who received CBD were analyzed as repeated measures over time using a mixed model, with significance at α = 0.05. Results: Average plasma CBD at 5 and 10 mg/kg were 97.3 ng/mL and 236.8 ng/mL pre-prandial, 341 ng/mL and 1,068 ng/mL postprandial, respectively. PK parameters suggested CBD accumulation over time, with significant increases in Cmax and AUC at both the 18 and 36-week timepoints. Cmax and AUC were dose proportional. Half-life demonstrated large inter-individual variations and increased (p < 0.05) at weeks 18 and 36 compared to baseline. Volume of distribution was not affected by time or treatment, while MRT increased, and clearance decreased over time (p < 0.05). Conclusions and clinical importance: Chronic administration of CBD to healthy adult dogs led to a dose-proportional accumulation in the body for 36 weeks, which was confirmed by an increased half-life, total exposure, mean residence time and plasma peak. Our data also suggests that CBD plasma levels may have less daily variation if administered twice daily.

Substrate degradation and postbiotic analysis of alternative fiber ingredients fermented using an in vitro canine fecal inoculum model.

Many fiber ingredients are used by the pet food industry; however, little data are available regarding the fermentation characteristics of alternative fibers currently being used. The objectives of this study were to determine organic matter disappearance (OMD) and postbiotic production from various fruit and vegetable fiber sources using an in vitro dog fecal inoculum model. Apple pomace (AP), blueberry pomace (BP), cranberry pomace (CP), tomato pomace (TP), and pea fiber (PF) were used as experimental treatments. Inoculum was prepared using freshly voided feces under anaerobic conditions. Predigested fibers were inoculated and incubated for 1, 3, 6, and 12 h at 39 °C. Short-chain fatty acids (SCFA), branched-chain fatty acids (BCFA), total volatile fatty acids (VFA), and OMD were determined for each fiber source and time point in triplicate. After 12 h of incubation, OMD was similar (P > 0.05; average of 18.5%) among treatments. Proportionally, acetate was greater for BP and AP (P < 0.05; average of 80.1%) than for the other treatments (68.3% to 71.2%). Molar proportions of propionate was greatest (P < 0.05) for CP (26.8%) compared to the remaining treatments (13.6 to 20.7%). Butyrate was proportionally greater for PF (7.7%; P < 0.05) than for BP and CP (average of 4.8%) and was lowest for AP (3.8%); however, TP was not different from PF (P > 0.05; average of 7.25%). Total VFA concentration was highest for AP (P < 0.05) followed by TP (1.17 and 0.75 mmol*g-1 of substrate, respectively). Both BP and PF were similar (average of 0.48 mmol*g-1 of substrate) and lower than for TP, with CP having the lowest VFA concentration (0.21 mmol*g-1 of substrate) among all treatments. Additionally, when comparing molar concentrations, AP and TP (average of 0.0476 mmol*g-1 of substrate) had greater butyrate concentrations than did PF (0.0344 mmol*g-1 of substrate). The AP, BP, and TP treatments had both linear and quadratic relationships (Table 7; P < 0.05) for acetate, propionate, and butyrate concentrations across time. CP only demonstrated a linear relationship for propionate (P < 0.05), whereas acetate and butyrate had quadratic relationships with time. PF only demonstrated quadratic relationships between acetate, propionate, and butyrate concentrations and time (P < 0.05). Overall, the fiber substrates evaluated were marginally to moderately fermentable when incubated for up to 12 h with canine fecal inoculum.

Fibers fermented in the gut result in the production of short-chain fatty acids (SCFA) acetate, propionate, and butyrate. These postbiotic compounds, particularly butyrate, play an important role in colonic and host health. Fibers not degraded by the microbiota aid in stool formation and promote laxation. Many fiber ingredients are used in pet diets; however, data regarding the fermentation characteristics of alternative fiber ingredients are scarce. In this work, substrate degradation and postbiotic analysis were evaluated for apple pomace (AP), blueberry pomace (BP), cranberry pomace (CP), pea fiber (PF), and tomato pomace (TP) incubated for 1, 3, 6, and 12 h at 39 °C using canine fecal inoculum. After 12 h, substrate degradation was not different among treatments due to high variability. AP had the highest concentration of total SCFA, followed by TP, BP, PF, and CP. The molar proportion of acetate was greatest for AP and BP. CP had the highest molar proportion of propionate. PF had greater molar proportions of butyrate than did AP, BP, and CP, but had similar molar proportions as TP. Additionally, the molar concentrations of butyrate were greatest for AP and TP. Overall, fiber substrates were marginally to moderately fermentable when incubated for up to 12 h with canine fecal inoculum.

Scientific Validation of Cannabidiol for Management of Dog and Cat Diseases.

Cannabidiol (CBD) is a non-psychotropic phytocannabinoid of the plant Cannabis sativa L. CBD is increasingly being explored as an alternative to conventional therapies to treat health disorders in dogs and cats. Mechanisms of action of CBD have been investigated mostly in rodents and in vitro and include modulation of CB1, CB2, 5-HT, GPR, and opioid receptors. In companion animals, CBD appears to have good bioavailability and safety profile with few side effects at physiological doses. Some dog studies have found CBD to improve clinical signs associated with osteoarthritis, pruritus, and epilepsy. However, further studies are needed to conclude a therapeutic action of CBD for each of these conditions, as well as for decreasing anxiety and aggression in dogs and cats. Herein, we summarize the available scientific evidence associated with the mechanisms of action of CBD, including pharmacokinetics, safety, regulation, and efficacy in ameliorating various health conditions in dogs and cats.

A review: nutrition and process attributes of corn in pet foods.

Corn is one of the largest cereal crops worldwide and plays an important role in the U.S. economy. The pet food market is growing every year, and although corn is well utilized by dogs, some marketing claims have attributed a negative image to this cereal. Thus, the objective of this work was to review the literature regarding corn and its co-products, as well as describe the processing of these ingredients as they pertain to pet foods. Corn is well digested by both dogs and cats and provides nutrients. The processing of corn generates co-products such as corn gluten meal and distillers dried grains with solubles that retain quality protein, and fibrous components that dilute dietary energy. Further, corn has much functionality in extrusion processing. It may yield resistant starch under certain processing conditions, promoting colonic health. Carotenoids in corn may enhance immune support in companion animals if concentrated. Mycotoxin contamination in grains represent a health hazard but are well controlled by safety measures. Genetically modified (GM) corn is still controversial regarding its long-term potential for mutagenicity or carcinogenicity, thus more long-term studies are needed. In conclusion, the negative perception by some in the pet food market may not be warranted in pet foods using corn and its co-products.

Extrusion Processing Modifications of a Dog Kibble at Large Scale Alter Levels of Starch Available to Animal Enzymatic Digestion.

The objective of the present work was to produce dog foods from a single recipe at three levels of resistant starch (RS). The low (LS), medium (MS), and high shear (HS) foods were produced on a single-screw extruder at target screw speeds of 250, 375 and 460 rpm, respectively, and with increasing in-barrel moisture as shear decreased. Post-production, kibble measurements and starch analyses were conducted. Kibble parameters were compared by ANOVA with significance noted at p < 0.05 with a single degree of freedom orthogonal contrasts for extrusion outputs, starch analyses, and viscosity (RVA). The MS and LS kibbles exiting the extruder were denser and less expanded (p < 0.05) than the HS treatment. Resistant starch, starch cook, and raw:cooked starch RVA AUC increased linearly as shear decreased. These results confirmed that lower mechanical energy processes led to decreased starch gelatinization and greater retention of in vitro RS.

A Low to Medium-Shear Extruded Kibble with Greater Resistant Starch Increased Fecal Oligosaccharides, Butyric Acid, and Other Saccharolytic Fermentation By-Products in Dogs.

The objective of this study was to assess whether diets with increased resistant starch (RS) had a positive effect on markers of colonic health in dogs. Three identical diets were extruded with high, medium and low shear (HS, MS and LS) to incrementally increase RS, and fed to 24 dogs in a replicated 3 × 3 William's Latin square design for 28-day periods. Fasting blood and fresh feces were collected on the last week of each period. Fecal quality was maintained among treatments. Gut integrity markers were measured by ELISA. Fecal short-chain fatty acids (SCFAs) were measured by LC MS/MS. In addition, the microbiota of dogs was determined from fresh feces by 16s rRNA high throughput sequencing. Untargeted metabolomics of both feces and serum were determined by UPLC. Data were analyzed using mixed models. There were no treatment effects on satiety hormones or gut integrity markers. Dogs fed LS or MS diets had marginal evidence (p < 0.10) for decreased fecal pH and for higher concentration (p < 0.05) of butyric acid and fecal oligosaccharides, succinate and lactate. Also, dogs fed the MS or LS diets had a shift towards more saccharolytic bacteria.

Starch characterization of commercial extruded dry pet foods.

Starches provide an effective energy source for dogs and cats and can affect health according to its inclusion and extent of digestion. The starch fraction that escapes small intestine (SI) digestion is called resistant starch (RS) and is desirable due to its prebiotic function. Starch is not an essential nutrient for dogs and cats and thus is not reported on commercial pet food labels. Hence, the objective of this work was to characterize starches in commercial pet foods. The top five pet food companies by sales were selected to represent U.S. pet foods, which were divided into four strata with a sampling frame of 654 foods: dog grain based (372 foods), dog grain free (71 foods), cat grain based (175 foods), and cat grain free (38 foods). Five random foods within each stratum were purchased (20 total). Starch analyses (total starch, resistant starch, and starch cook), as well as nutrient analyses were conducted on all foods. Total starch, RS, and starch cook means were compared using a two-group Z-test on dog vs. cat and grain-based (GB) vs. grain-free (GF) diets, and differences were considered significant at a P < 0.05. Total starch was higher (P < 0.05) in dog than cat food, and starch cook was greater (P < 0.05) in GF diets. A regression analysis showed that nitrogen-free extract was a good predictor of total starch. Resistant starch was low and not different among groups. A post hoc test showed that a total sample size of at least 28 diets per group would be required to detect differences in RS between GF and GB diets, if one exists.

Evaluation of faba beans as an ingredient in dog diets: apparent total tract digestibility of extruded diets with graded levels of dehulled faba beans (Vicia faba L.) by dogs.

The growing pet food market is continuously in search for novel ingredients. Legumes such as faba beans (FB) are increasing in popularity and are known to benefit human health, but little is known about their use in pet foods. The objective of this study was to determine the effect of dehulled FB utilization by dogs. Experimental diets were extruded with 0%, 10%, 20%, and 30% FB inclusion (FB0, FB10, FB20, and FB30, respectively). Beagle dogs (n = 12) were fed the diets for 9-d adaptation with 5-d total fecal collection in a replicated 4 × 4 Latin square design. Apparent total tract digestibility (ATTD) was determined by external marker Cr2O3. At the culmination of each period, blood samples were collected from brachial venipuncture for complete blood count and blood chemistry. Palatability was determined with a 2-bowl test (n = 20). Means of blood parameters were separated by multivariate analysis of variance (MANOVA) with the aid of statistical software (SAS v9.4). Contrasts and least square means of fecal parameters and ATTD were computed. Significance level was considered to be α = 0.05. Dogs ate all food on offer and maintained body weight. There was no difference (P > 0.05) among treatments (FB10, FB20, and FB30) and the control (FB0) relative to food intake, fecal output ("as is" basis), and fecal score, but feces were softer when dogs were fed the treatments (P = 0.031) and there was a linear increase (P = 0.011) in defecation frequency (stools/day) when FB increased in the diets. Dry matter, organic matter, and crude protein digestibilities were slightly higher when dogs were fed the control diet (P < 0.05) compared with the FB diets. All blood and serum chemistry parameters were similar among treatments and within the reference ranges. Dogs preferred the control diet relative to the 10% and 30% FB diets, but the 20% FB preference was similar to the control. Dogs remained healthy, maintained body weight and no adverse health events were observed during the study. Dehulled FB are a suitable ingredient for dog foods, but concentrations should not exceed 20% to avoid reduction in palatability and stool quality.

The Effect of Increasing Levels of Dehulled Faba Beans (Vicia faba L.) on Extrusion and Product Parameters for Dry Expanded Dog Food.

The growing pet food market is continuously in search for novel ingredients. Legumes such as faba beans are increasingly popular in human nutrition but have not yet been explored in pet foods. Extruded dog diets were produced with 0, 10, 20, and 30% dehulled faba bean (DFB) inclusion (FB0, FB10, FB20, and FB30, respectively) in exchange for rice and corn gluten meal. Fixed processing inputs were extruder screw configuration, die size (5.2 mm diameter), dry feed rate (237 kg/h), extruder water and steam (0%), and die knife speed (1100 rpm). Variable inputs were managed by an operator with the goal to obtain similar kibble bulk density at the extruder die (OE) across treatments. Output parameters were measured at the pre-conditioner, extruder, and kibble. Measurements were collected at uniform time increments during production of each experimental diet and considered treatment replicates. Single degree of freedom contrasts were analyzed on extrusion and product outputs. The target of producing diets with similar wet bulk density was achieved, with moderate modifications at the pre-conditioner (PC) and extruder. As DFB increased, diets had increased retention time and water at the PC to improve starch hydration and swelling. The FB20 and FB30 required a more restricted flow to improve kibble expansion. After drying, the FB20 and FB30 diets were denser, harder and tougher (p < 0.05) than FB0 and FB10. The increasing levels of DFB up to 30% can be effectively controlled in an extruded pet food application with modest changes to extrusion parameters.

Influence of Liver Condition and Copper on Selective Parameters of Post-Mortem Dog Tissue Samples.

One of the liver functions is copper storage, which can be toxic when in excess. The objective of this retrospective study was to determine the relationship between hepatic copper and pathology conditions in stored samples from 55 post-mortem dogs (37 Beagles, 12 Labrador Retrievers, and 6 Labrador Mixes). The analyses evaluated data from blood chemistry and complete blood count (CBC) that were measured immediately before euthanasia, and liver biopsies which were harvested at necropsy and frozen at -80 °C. Slides for microscopic evaluation were prepared, and liver copper and plasma metabolites were measured. Hepatic copper was correlated (p ≤ 0.001) with monoacylglycerols, 13-HODE + 9-HODE (13-hydroxy-9,11-octadecadienoic acid + 9-hydroxy-10,12-octadecadienoic acid), and stearoyl-arachidonoyl-glycerophosphocholine. This indicates lipid metabolism modification and cell membrane oxidation. However, hepatic copper was not related to liver histopathology severity or altered liver biomarkers. The severity of liver pathology was positively correlated (p ≤ 0.05) with liver enzymes, bile salts, and glycerophosphocholines, suggesting cholestasis and altered lipid and amino acid metabolism. Liver neoplasia had increased (p ≤ 0.05) metabolites derived from nucleotides, along with an increase (p ≤ 0.05) in α-ketoglutarate from the energy and amino acid metabolism (p ≤ 0.05), suggesting rapid cell division. This study offers further insight regarding changes in metabolism due to hepatic tissue damage.

The effect of sorghum fractions on apparent total tract digestibility and antioxidant capacity by dogs.

Sorghum is an abundant starch source that has many potential health benefits. Some pet food companies have adopted whole sorghum in their formulations, however sorghum flour and (or) its phenolic rich seed coat might provide added benefit to companion animal diets. The objective of this experiment was to evaluate diets utilizing sorghum flour (FLD), and sorghum mill feed (MFD) relative to whole sorghum (WSD), and conventional grains (rice, corn and wheat; CON) in a typical dog diet. Adult (1-3 yr) Beagle dogs (n = 12; 10.6 kg ± 1.4) were randomly assigned to individual pens with ad libitum access to water. Dogs were fed twice daily and adapted to diet (9 d), and then total feces were collected for 5 d over 4 periods in a 4x4 replicated Latin square design. Fecal output for determination of digestibility was estimated using Cr2O3 as a marker. Number of defecations were quantified, and feces were scored. Approximately 3 mL of blood from each dog was collected at the end of each period and stored at -80° until further analyses. Means were separated using multivariate analysis of variance (MANOVA). Intake did not differ among treatments (average 187 g/d), but dogs fed the MFD excreted a larger (P<0.05) amount of feces, had more defecations per day, and lower (P<0.05) overall nutrient digestibility compared to the other treatments. The FLD had the highest (P<0.05) dry matter (DM), organic matter (OM), crude protein (CP) and gross energy (GE) digestibility, suggesting a possible application in "easy-to-digest" pet foods. Dogs fed the MFD had the highest (P < 0.05) plasma oxygen radical absorbance capacity (ORAC) value, but plasma ferulic and p-coumaric acids did not differ among treatments. Sorghum fractions have potential application in pet food; wherein, a bran rich fraction may promote antioxidant capacity, and flour increased digestibility.