An experimental meat-free diet maintained haematological characteristics in sprint-racing sled dogs

Domestic dogs maintain clinical, nutritional, and hematological health outcomes when fed a commercial plant-based diet for a year

Domestic dogs can maintain health on complete and well-balanced canine plant-based nutrition (K9PBN). Novel insight on health outcomes in dogs consuming K9PBN is of relevance to veterinary professionals and consumers given a growing interest in non-traditional dog foods with perceived health benefits, while considering potential safety concerns. We aimed to investigate nutritional equivalence by measuring clinical health outcomes in adult dogs fed K9PBN over twelve months compared to a meat-based diet at baseline. We enrolled fifteen clinically healthy adult dogs living in households in Los Angeles County, California in a prospective cohort study and evaluated clinical, hematological, and nutritional parameters in dogs at 0, 6, and 12 months, including complete blood count (CBC), blood chemistry, cardiac biomarkers, plasma amino acids, and serum vitamin concentrations. The study found that clinically healthy, client-owned, adult dogs maintain health, based on physical exams, complete blood count, serum chemistry, plasma amino acids, serum vitamins, and cardiac biomarkers combined with client-reported observations, when fed commercial K9PBN over a twelve-month period. This study is the most comprehensive and longest known K9PBN investigation to date and provides clinically relevant evidence-based nutrition data and new knowledge on outcomes in clinically healthy dogs who thrive without consumption of animal-derived ingredients. These results also provide a valuable foundation for the future study of K9PBN as a potential nutritional intervention for clinically relevant pathologies in canine medicine. Lastly, it is of major relevance to One Health paradigms since ingredients produced independent of industrial food animal production are both more sustainable and help to circumvent ethical dilemmas for maintenance of health in domestic dogs.

Efficacy of vitamin D2 in maintaining serum total vitamin D concentrations and bone mineralisation in adult dogs fed a plant-based (vegan) diet in a 3-month randomised trial

Dogs are considered omnivores based on their evolution consuming diets including animal tissue. Few feeding trials evaluating the nutritional suitability of exclusively plant-based (vegan) diets in dogs have been published, and the efficacy of vitamin D2 in maintaining canine serum vitamin D levels has not been clearly determined. A blinded dietary trial included sixty-one healthy desexed adult dogs: thirty-one fed an experimental extruded vegan diet (PLANT) and thirty fed a commercial extruded meat-based diet (MEAT) for 3 months. Dogs were screened via veterinary examination and routine laboratory analyses prior to enrolment, at baseline and exit timepoints. Body composition was measured by dual-energy X-ray absorptiometry and blood was collected for vitamin D profiling. All dogs maintained health parameters, body weight and composition throughout the study. Dogs maintained on PLANT demonstrated a significant reduction in platelet count, creatinine, blood urea nitrogen and cholesterol, though values remained within normal reference ranges. Dogs fed PLANT also demonstrated a shift from vitamin D3 to vitamin D2 metabolites, though total vitamin D analogue levels were unchanged, with the exception of 24,25-dihydroxyvitamin D. Bone mineral content and density did not differ from baseline values. Health status was maintained in dogs fed PLANT and vitamin D2 appeared efficacious in maintaining serum total vitamin D concentrations and bone mineralisation. Findings support the hypothesis that PLANT was comparable to MEAT for maintenance of healthy adult dogs for at least 3 months and identified areas where further research is warranted to elucidate the potential risks and benefits of plant-based (vegan) diets.

The relative benefits for environmental sustainability of vegan diets for dogs, cats and people

Environmental impacts of the livestock sector are proportional to consumption levels. To assess the relative consumption of livestock animals within the diets of dogs, cats and people, this study examined their dietary energy needs within the US in 2020, and globally in 2018. Also studied were US pet food ingredients, and environmental sustainability indicators for plant- and animal-based foods consumed globally. Relative consumptions of average livestock animals were: US: dogs- 17.7%, cats- 2.3%, humans- 80.0%; and globally: dogs- 7.7%, cats- 1.2%, humans- 91.1%. Full transition to nutritionally-sound vegan diets would spare from slaughter the following numbers of terrestrial livestock animals annually (billions): US: dogs- 1.7, cats- 0.2, humans- 7.8, and globally: dogs- 6.0, cats- 0.9, humans- 71.3, as well as billions of aquatic animals in all dietary groups. Very large impact reductions were also associated with land and water use, emissions of greenhouse gases (GHGs), acidifying and eutrophifying gases, and biocide use, in all dietary groups. If implemented globally, nutritionally-sound vegan diets would free up land larger than the following nations: dogs-Saudi Arabia or Mexico, cats-Japan or Germany, humans-Russia-the world's largest country-combined with India. Such diets would save freshwater volumes greater than all renewable freshwater in the following nations: dogs-Denmark, cats-Jordan, humans-Cuba. Such diets would reduce GHGs by amounts greater than all GHG emissions from following nations: dogs-South Africa or the UK, cats-Israel or New Zealand, humans-India or the entire EU. The numbers of additional people who could be fed using food energy savings associated with vegan diets exceeded the 2018 human populations of the following nations: dogs-the entire European Union, cats-France or the UK, humans-every single nation or collective region on Earth, as defined by the World Bank. All of these estimates are conservative.

The Impact of Vegan Diets on Indicators of Health in Dogs and Cats: A Systematic Review

There has been an increase in vegetarianism and veganism in human populations. This trend also appears to be occurring in companion animals, with guardians preferring to feed their animals in accordance with their own dietary values and choices. However, there has been controversy amongst vets and online commentators about the safety of feeding vegan diets to carnivorous species, such as cats and dogs. In spite of this controversy, to date there has been no systematic evaluation of the evidence on this topic. A systematic search of Medline, Scopus, and Web of Science was performed, identifying 16 studies on the impact of vegan diets on cat and dog health. Studies were appraised for quality using established critical appraisal tools or reporting guidelines. There was considerable heterogeneity in the outcomes measured, and study designs employed, with few studies evaluating key outcomes of interest. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was utilized for assessment of certainty in the evidence, with the evidence for most outcomes being assessed as low or very low. Whilst the quality and amount of evidence needs to be considered in formulating recommendations, there was no overwhelming evidence of adverse effects arising from use of these diets and there was some evidence of benefits. It is, however, recommended that future high-quality studies, with standardized outcome measures and large sample sizes, be conducted. At the current time, if guardians wish to feed their companion animals vegan diets, a cautious approach should be taken using commercially produced diets which have been formulated considering the nutritional needs of the target species.

The impact of protein source and grain inclusion on digestibility, fecal metabolites, and fecal microbiome in adult canines

This study was conducted to determine the effect of animal protein inclusion rate and grain-free or grain-inclusive diets on macronutrient digestibility, fecal characteristics, metabolites, and microbiota in mixed-breed hounds and Beagles. Four experimental extruded kibble diets were made with varying amounts of animal protein and carbohydrates: 1) high animal protein, grain-inclusive (HA-GI), 2) low animal protein, grain-free (LA-GF), 3) low animal protein, grain-inclusive (LA-GI), and 4) high animal protein, grain-free (HA-GF). Thirty-two Beagles and 33 mixed-breed hounds were assigned to 1 of the 4 treatment groups in a completely randomized design that lasted 180 d. All diets were similar in chemical composition and well-digested by the animals. In general, for fecal metabolites, mixed-breed hounds had a greater concentration of total short-chain fatty acid (SCFA) and ammonia and lower indole concentration than Beagles (P < 0.05). In mixed-breed hounds, LA-GF had a greater (P < 0.05) total SCFA concentration than HA-GI and LA-GI; however, this was not observed in Beagles. There were greater concentrations of ammonia, phenol, and indole in HA-GI than in LA-GF (P < 0.05). Breed-affected fecal primary bile acid (BA) concentration, as mixed-breed hounds had a greater concentration of cholic acid (CA) than Beagles (P < 0.05). Mixed-breed hounds fed LA-GF resulted in greater CA concentrations than HA-GI and LA-GI (P < 0.05). Dogs who consumed LA-GF had lower fecal secondary BA content than the other groups (P < 0.05). The distribution of the fecal microbiota community differed in LA-GF compared with the other groups, with lower α-diversity. However, dogs fed LA-GF had the largest difference in composition with greater Selenomonadaceae, Veillonellaceae, Lactobacillaceae, Streptococcus, Ligilactobacillus, Megamonas, Collinsella aerofaciens, and Bifidobacterium sp. than the other groups. A significant breed effect was noted on nutrient digestibility, fecal metabolites, and microbiota. A treatment effect was observed in LA-GF as it resulted in greater fecal SCFA, lower protein fermentative end products, greater fecal primary BAs, lower fecal secondary BA concentrations, and shifts in fecal microbiota.

Owner perception of health of North American dogs fed meat- or plant-based diets

BACKGROUND

Some dog owners elect to feed their dog a plant-based food either as part of or for their entire dietary intake. Being omnivores or facultative carnivores, a strictly plant-based diet is not the natural type of food dogs evolved to consume, leaving some question as to whether this feeding management strategy is safe and healthy for dogs.

OBJECTIVES

This study surveyed owner perceptions of health and wellbeing of dogs and compared between those fed meat-based and plant-based diets.

METHODS

A web-based questionnaire was distributed to pet owners to collect data on dog characteristics, husbandry, health and wellbeing. Univariate comparisons between diet groups was made by chi square analyses or Kaplan-Meier tests as appropriate, with a significance cut-off value of 0.05. Multivariate models were negative binomial and logistic regression for count and categorical data, respectively.

RESULTS

Owners feeding plant-based diets to their dog reported fewer health disorders, specifically with respect to ocular or gastrointestinal and hepatic disorders. Dog longevity was reported to be greater for dogs fed plant-based diets. Owners feeding plant-based diets to their dogs relied less on veterinary associates for nutrition information, versus dog owners feeding meat-based diets.

CONCLUSIONS

Dog owners feeding a plant-based diet did not perceive adverse health effects in their dogs. The results might suggest an association between feeding a plant-based diet and perceived health and longevity, however inherent bias and limitations associated with surveys of owner perception must be considered, and objective research is required to determine if plant-based diets truly affect canine health.

Vegan versus meat-based dog food: Guardian-reported indicators of health

Alternative pet foods may offer benefits concerning environmental sustainability and the welfare of animals processed into pet foods. However, some worry these may compromise the welfare of pets. We asked 2,639 dog guardians about one dog living with them, for at least one year. Among 2,596 involved in pet diet decision-making, pet health was a key factor when choosing diets. 2,536 provided information relating to a single dog, fed a conventional meat (1,370 = 54%), raw meat (830 = 33%) or vegan (336 = 13%) diet for at least one year. We examined seven general indicators of ill health: unusual numbers of veterinary visits, medication use, progression onto a therapeutic diet after initial maintenance on a vegan or meat-based diet, guardian opinion and predicted veterinary opinion of health status, percentage of unwell dogs and number of health disorders per unwell dog. Dogs fed conventional diets appeared to fare worse than those fed either of the other two diets. Dogs fed raw meat appeared to fare marginally better than those fed vegan diets. However, there were statistically significant differences in average ages. Dogs fed raw meat were younger, which has been demonstrated to be associated with improved health outcomes. Additionally, non-health related factors may have improved apparent outcomes for dogs fed raw meat, for three of seven general health indicators. We also considered the prevalence of 22 specific health disorders, based on predicted veterinary assessments. Percentages of dogs in each dietary group considered to have suffered from health disorders were 49% (conventional meat), 43% (raw meat) and 36% (vegan). Significant evidence indicates that raw meat diets are often associated with dietary hazards, including nutritional deficiencies and imbalances, and pathogens. Accordingly, the pooled evidence to date indicates that the healthiest and least hazardous dietary choices for dogs, are nutritionally sound vegan diets.

A Comparison of Key Essential Nutrients in Commercial Plant-Based Pet Foods Sold in Canada to American and European Canine and Feline Dietary Recommendations

Simple Summary

Plant-based pet foods appear to be growing in popularity, but it is unclear how suitable these products are for dogs and cats, considering both species naturally consume diets rich in, or exclusively comprised of, animal tissues. Laboratory analyses of essential nutrients were performed on 26 plant-based diets available in Ontario, Canada in 2018, including 18 canine products (13 products labelled for adult maintenance, four for all life stages, one for puppy growth), 5 feline products (two for adult maintenance and three for all life stages), and 3 products labelled for both dogs and cats (one for adult maintenance and two for all life stages). The nutrient measurements were compared to industry standard nutrient profiles. Four products met the recommendations of the Association of American Feed Control Officials and one product the nutrient recommendations of the European Pet Food Industry Federation for adult dogs. No diets met recommended nutrient content for adult cats or growing puppies or kittens. Nutrients most commonly found to be insufficient were: sulfur amino acids, taurine, arachidonic acid, EPA and DHA, calcium phosphorus and vitamin D. These nutrients are all typically found in animal tissues, though non-animal sources are available, and require careful formulation or supplementation in products made without animal-derived ingredients. Compliance with Canadian labelling regulation and guidelines was poor. These problems do not appear to be exclusive to plant-based foods and have been demonstrated previously in commercially available animal-based products as well. This study demonstrates areas where manufacturers of plant-based pet foods must improve formulation and/or manufacturing practices to produce products appropriate for feeding cats and dogs.

Abstract

Plant-based foods intended for feeding dogs and cats are available in Canada, though few studies have examined the suitability of plant-based foods for dogs and cats. All commercial plant-based extruded and wet pet food products available in Ontario, Canada, in 2018 (n = 26) were acquired and analysed for energy, crude protein, crude fat, crude fibre, ash, amino acids, fatty acids, minerals and vitamins A, B₁₂, D₂ and D₃. Results were compared with recommendations of the Association of American Feed Control Officials (AAFCO) and the European Pet Food Industry Federation (FEDIAF). Thirteen products were labelled for adult canine maintenance, four for canine all life stages, one for puppy growth, two for adult feline maintenance, three for feline all life stages, one for adult maintenance of dogs and cats and two for all life stages of dogs and cats. Four products met AAFCO and one product met FEDIAF nutrient recommendations for canine maintenance. No diets met AAFCO or FEDIAF recommendations for feline maintenance or growth for either species. Nutrients most commonly found insufficient were: sulfur amino acids, taurine, arachidonic acid, EPA and DHA, calcium phosphorus and vitamin D. There were no nutrients unable to be provided from non-animal sources. Compliance with labelling guidelines was also poor, similar to other findings with commercial animal-based pet products. The results from this study indicate areas where producers of plant-based pet foods must improve to meet the industry recommended nutrient profiles and labelling requirements.

Vegan versus meat-based pet foods: Owner-reported palatability behaviours and implications for canine and feline welfare

Consumer suspicion of conventional pet foods, along with perceived health benefits of alternative diets, are fuelling development of the latter. These include raw meat diets, in vitro meat products, and diets based on novel protein sources such as terrestrial and marine plants, insects, yeast and fungi. However, some claim vegan diets may be less palatable, or may compromise animal welfare. We surveyed 4,060 dog or cat guardians to determine the importance to them of pet food palatability, and the degree to which their animals displayed specific behavioural indicators of palatability at meal times. Guardians were asked to choose one dog or cat that had been within their household for at least one year, and not on a prescription or therapeutic diet. Of 3,976 respondents who played some role in pet diet decision-making, palatability was the third most important among 12 factors cited as important when choosing pet diets. For 1,585 respondents feeding conventional or raw meat diets, who stated they would realistically consider alternative diets, palatability was the fourth most important among 14 desired attributes. For the 2,308 dogs included, reported observations of 10 behavioural indicators of palatability at meal times reliably indicated significant effects of increased reports of appetitive behaviour by dogs on a raw meat diet, as opposed to a conventional diet. There was no consistent evidence of a difference between vegan diets and either the conventional or raw meat diets. For the 1,135 cats included, reported observations of 15 behavioural indicators indicated that diet made little difference to food-oriented behaviour. Based on these owner-reported behaviours, our results indicate that vegan pet foods are generally at least as palatable to dogs and cats as conventional meat or raw meat diets, and do not compromise their welfare, when other welfare determinants, such as nutritional requirements, are adequately provided.

Soybean meal and poultry offal meal effects on digestibility of adult dogs diets: Systematic review

Soybean meal and poultry offal meal are protein ingredients commonly used in the formulation of commercial diets for dogs. However, there remains great variability in the data on the digestibility of each protein source. This systematic review study aimed to examine the intake, apparent nutrient digestibility coefficients and fecal output of protein sources (soybean meal and poultry offal meal) in adult dog food as reported in published studies. The article search was conducted in August 2018 in the PUBMED, SciELO, Science Direct and AGRIS indexing databases. The literature search was performed using "digestibility", "source protein" and "dog" as the main key terms combined with sub-terms to broaden the scope of the search. Criteria were defined for readability, exclusion and inclusion of articles. Results were organized in groups according to the search in the indexing databases, totaling 1,414 articles. After the works were selected following the inclusion criteria, 17 articles were evaluated in this review. According to most studies, plant-based ingredients have a less variable nutritional composition than animal-derived ingredients and poultry offal meal increases the digestibility coefficients of nutrients and energy and reduces fecal dry matter production. Factors inherent to raw-material origin, ingredient and food processing, as well as the high heterogeneity of the methodologies evaluated in the studies are directly related to the obtained results. To ensure a more accurate evaluation of the quality and of effects on the digestibility of protein sources, we recommended that articles include ingredient processing data and that the variables be evaluated under standardized study conditions.

Clinical Findings in Healthy Dogs Fed With Diets Characterized by Different Carbohydrates Sources

In recent years, pet owners have become more interested in the ingredients, and quality of pet-food, and several studies have demonstrated that feed management could affect healthy status. Recently, some authors indicated that commercial diets formulated without cereals, or using unconventional protein, and starch sources, can cause a reduction in taurine levels in both whole blood, and plasma. Nevertheless, the specific mechanism by means of which nutritional factors determine this reduction is not completely clear. Thirty neutered half-breed dogs were recruited at a kennel in the province of Naples (Italy) to investigate the influence of carbohydrates sources, and dietary density of nutrients on healthy status of dogs in terms of blood count, and biochemical parameters. The dogs were housed in the kennel and divided into three distinct groups. Three iso-energy, and iso-nitrogen commercial kibble diets (named GF1, GF2, and CB) with different protein, and carbohydrates contents, and carbohydrates sources were chosen for the trial. The chemical composition and amino acid profile of each of the three tested diets were analyzed. Moreover, blood samples of each dog were collected to evaluate the hematological and biochemical profiles. The taurine level was determined both on plasma and whole blood. The effect of the diets was analyzed statistically, and all tested diets were compared to the control one. There were significant differences between the three tested diets as regards their chemical composition. The concentrations of all amino acids seem to reflect protein content diets. The hematological profile resulted within the ranges considered physiological for the canine species for all subjects. Compared to the control diet, the three tested diets showed significant differences in blood count for MCHC and platelets. The biochemical profile showed significant differences between the diets, particularly their AST, fructosamine, lipase, and triglycerides values. The diets did not affect the blood and plasma taurine levels. They resulted in higher than optimal reserve levels. Preliminary results showed that the sources of carbohydrates and use of balanced diets affected only some biochemical parameters and did not alter the levels of taurine in healthy adult dogs.

An observational study of pet feeding practices and how these have changed between 2008 and 2018

BACKGROUND

Pet owners have many feeding options, some may be considered unconventional by veterinary practitioners. Provision of appropriate nutrition is a basic requirement, with adverse health outcomes possible when a pet diet is inadequate.

OBJECTIVE

To capture dog and cat feeding practices, with a special focus on countries with large English-speaking populations, and to compare with data published over the previous 10 years.

METHODS

An electronic questionnaire was provided for dog and cat owners online. Responses were analysed using descriptive statistics, and comparisons made with data from nine peer-reviewed articles published over the previous 10 years.

RESULTS

Responses from 3673 English-speaking dog and cat owners in Australia, Canada, New Zealand, the UK and the USA were included. In previous publications, conventional (commercial, heat-processed) products were the predominant method of feeding. In recent publications, feeding unconventional (raw, homemade, vegetarian) diets appeared more prevalent. In the present study, most (79 per cent dogs, 90 per cent cats) pets were offered conventional food. However a few (13 per cent dogs, 32 per cent cats) pets were fed conventional foods exclusively. Many pets were offered homemade (64 per cent dogs, 46 per cent cats) and/or raw (66 per cent dogs, 53 per cent cats) foods. Different feeding practices were associated with geographical location.

CONCLUSION

As an increased risk of nutrient insufficiency and associated conditions have been attributed to unconventional feeding practices, veterinarians must be aware of pet feeding trends and educate clients about the nutritional needs of companion animals.

Plant-based (vegan) diets for pets: A survey of pet owner attitudes and feeding practices

People who avoid eating animals tend to share their homes with animal companions, and moral dilemma may arise when they are faced with feeding animal products to their omnivorous dogs and carnivorous cats. One option to alleviate this conflict is to feed pets a diet devoid of animal ingredients-a 'plant-based' or 'vegan' diet. The number of pet owners who avoid animal products, either in their own or in their pets' diet, is not currently known. The objective of this study was to estimate the number of meat-avoiding pet owners, identify concerns regarding conventional animal- and plant-based pet food, and estimate the number of pets fed a plant-based diet. A questionnaire was disseminated online to English-speaking pet owners (n = 3,673) to collect data regarding pet owner demographics, diet, pet type, pet diet, and concerns regarding pet foods. Results found that pet owners were more likely to be vegetarian (6.2%; 229/3,673) or vegan (5.8%; 212/3,673) than previously reported for members of the general population. With the exception of one dog owned by a vegetarian, vegans were the only pet owners who fed plant-based diets to their pets (1.6%; 59/3,673). Of the pet owners who did not currently feed plant-based diets but expressed interest in doing so, a large proportion (45%; 269/599) desired more information demonstrating the nutritional adequacy of plant-based diets. Amongst all pet owners, the concern most commonly reported regarding meat-based pet foods was for the welfare of farm animals (39%; 1,275/3,231). The most common concern regarding strictly plant-based pet foods was regarding the nutritional completeness of the diet (74%; 2,439/3,318). Amongst vegans, factors which predicted the feeding of plant-based diets to their pets were concern regarding the cost of plant-based diets, a lack of concern regarding plant-based diets being unnatural, and reporting no concern at all regarding plant-based diets for pets. Given these findings, further research is warranted to investigate plant-based nutrition for domestic dogs and cats.

Vegetarian versus Meat-Based Diets for Companion Animals

Simple Summary

Many owners of companion animals are interested in vegetarian diets for their animals, as concerns increase about the consequences of animal farming, for health, animal welfare, and the environment. However, are vegetarian diets for cats and dogs nutritionally balanced and healthy? This article comprehensively reviews the evidence published to date from four studies that have examined the nutritional adequacy of vegetarian diets for cats and dogs. To obtain additional information, we surveyed 12 pet food companies detailed in the most recent study. We also examined the nutritional soundness of meat-based companion-animal diets, and reviewed the evidence concerning the health status of vegetarian, carnivorous and omnivorous companion animals. Both cats and dogs may thrive on vegetarian diets, but these must be nutritionally complete and reasonably balanced. Owners should also regularly monitor urinary acidity, and should correct urinary alkalinisation through appropriate dietary additives, if necessary.

Abstract

Companion animal owners are increasingly concerned about the links between degenerative health conditions, farm animal welfare problems, environmental degradation, fertilizers and herbicides, climate change, and causative factors; such as animal farming and the consumption of animal products. Accordingly, many owners are increasingly interested in vegetarian diets for themselves and their companion animals. However, are vegetarian canine and feline diets nutritious and safe? Four studies assessing the nutritional soundness of these diets were reviewed, and manufacturer responses to the most recent studies are provided. Additional reviewed studies examined the nutritional soundness of commercial meat-based diets and the health status of cats and dogs maintained on vegetarian and meat-based diets. Problems with all of these dietary choices have been documented, including nutritional inadequacies and health problems. However, a significant and growing body of population studies and case reports have indicated that cats and dogs maintained on vegetarian diets may be healthy—including those exercising at the highest levels—and, indeed, may experience a range of health benefits. Such diets must be nutritionally complete and reasonably balanced, however, and owners should regularly monitor urinary acidity and should correct urinary alkalinisation through appropriate dietary additives, if necessary.

Effect of graded inclusion of dietary soybean meal on nutrient digestibility, health, and metabolic indices of adult dogs

Two studies were conducted using adult dogs to evaluate the effect of increasing the inclusion of soybean meal (SBM) in an adult dog food on body composition, hematological and biochemical blood analyses, and total tract nutrient digestibility. Nutritionally complete and balanced diets were formulated with commercial-grade SBM (48% CP) to replace 0, 10, 20, or 30% of the protein provided by dried chicken protein resulting in final SBM inclusion of 0, 6.0, 11.5, and 17.0% (as-fed basis), respectively. In study 1, diets were fed during a 24-wk feeding trial using 36 female (spayed), adult hounds to evaluate food intake, BW, body composition, and blood measurements. There were no diet-related differences in food intake or BW. Body composition responded in a quadratic manner to increased dietary SBM inclusion with the percentage (%) of lean mass responding positively (P < 0.05) and absolute amounts of fat mass and percent body fat responding negatively (P < 0.05). All diagnostic blood components remained within normal physiological ranges for healthy, adult dogs. Serum concentrations of C-reactive protein and IGF-1 were similar among diets. In study 2, diets were evaluated in a digestibility study using 12 adult dogs in a 4 × 4 Latin square design. Increased SBM inclusion was associated with linear increases in the digestibility of CP (P < 0.05) and fat (P < 0.05) and CP retention (P < 0.05). Linear reductions in fecal DM content (P < 0.01) and increased fecal output (P < 0.05) were noted with increased SBM inclusion. All diets were similar in DE and ME content, but a quadratic trend was noted with increased SBM inclusion when DE (P = 0.083) and ME (P = 0.062) were expressed per unit of metabolic body size. Overall, it can be inferred from these results that the partial replacement of dried chicken protein with SBM in a nutritionally complete and balanced diet does not compromise the nutritional status and long-term health of adult dogs.