Assessment of macronutrients and fat quality in cat food

For certain nutrients, the European Pet Food Industry Federation (FEDIAF) provides minimum recommended levels that should be met in a cat's diet. The aim of this study was to assess the levels of essential nutrients and the quality of fats in commercial cat food. The material analyzed consisted of 27 dry cat food products, which were categorized into three groups based on their primary protein sources: poultry, fish, and alternative proteins. The proximate composition of ground samples was determined according to methods established by the Association of Official Analytical Chemists (AOAC). Fatty acid methyl esters were extracted from the samples and analyzed using gas chromatography coupled with mass spectrometry. All analyzed cat foods met the minimum recommended levels for protein and fat for adult cats, as established by FEDIAF (2024b). However, 11% of the products did not meet the minimum recommended level for linoleic acid (C18:2 n-6), and 14% lacked arachidonic acid (C20:4). The analysis confirmed that cat foods containing different types of animal-derived ingredients vary significantly in their individual fatty acid profiles.

Epidemiological and clinical profiles of young and senior dogs fed a standard diet

This study aimed to explore age-related differences in epidemiological and clinical parameters in dogs consuming a standardized diet, focusing on factors relevant to veterinary practitioners. A total of 106 dogs were included, comprising young (2-5 years) and senior (≥8 years) individuals. Epidemiological data were collected through questionnaires and veterinary consultations, while clinical parameters were assessed via physical examinations and blood analyses. Compared to younger dogs, senior dogs were less active, more likely to live in houses, and more frequently received regular deworming. They were also more likely to consume food purchased from pet stores or supermarkets compared to younger dogs. Clinical evaluations revealed that senior dogs had higher plasma globulin and platelets and lower albumin, consistent with chronic low-grade inflammation associated with aging. Muscle loss, poor coat quality, and reduced lymphocyte counts were also prominent in senior dogs, potentially reflecting sarcopenia, malnutrition, and immunosenescence, respectively. Notably, dogs previously fed diets lacking a source of omega-3 fatty acids exhibited elevated plasma triglycerides even after transitioning for four weeks to a premium diet containing fish oil, underscoring the lasting impact of long-term dietary habits. These findings highlight the importance of regular veterinary follow-ups for senior dogs and the role of high-quality nutrition, including sources of omega-3 fatty acids. By identifying key epidemiological and clinical differences, this study offers valuable insights to help veterinary practitioners distinguish between healthy and pathological aging.

Dogs fed a high protein, low carbohydrate diet have elevated postprandial plasma glucagon and amino acid concentrations and tend to have lower glucose concentrations compared to two different moderate protein, moderate carbohydrate diets

As dog owners continue to seek to feed their dogs similarly to themselves, there is demand for high protein, low carbohydrate (HPLC) diets. The consumption of HPLC diets can improve glycemic control, similarly to high fiber diets. However, the effects of HPLC and high fiber diets on cardiac function have yet to be evaluated in healthy dogs. The objective of the present study was to investigate the glucose, insulin, glucagon and amino acid (AA) postprandial response and echocardiographic measurements in laboratory-housed, adult large breed dogs fed a commercially available HPLC, a moderate protein, moderate carbohydrate (MPMC), or a commercially available MPMC, high fiber, "metabolic" diet for 42 d. This study was conducted as a 3 × 3 Latin square where dogs received: 1) a commercial HPLC diet (48% of metabolizable energy (ME) from protein, 10% of ME from nitrogen-free extract; NFE), 2) a MPMC diet (28% of ME from protein, 39% of ME from NFE) formulated with the same ingredients as HPLC or 3) a MPMC, high fiber, "metabolic" (MET) diet (30% of ME from protein, 37% of ME from NFE) as a commercial control. An echocardiogram and a 12-h glucose, insulin and glucagon response and 6-h AA meal response were performed on day 42 of feeding. Data were analyzed using proc glimmix in SAS (version 9.4). All echocardiographic parameters remained within a healthy reference range for dogs of this size. Dogs fed HPLC had a larger net area under the curve (NetAUC) for plasma glucagon (P < 0.001) compared to dogs fed MPMC and MET, a smaller NetAUC for glucose: insulin (P = 0.039) compared to dogs fed MPMC but MET was similar to both. Glucose NetAUC tended to be different among treatments (P = 0.057), where dogs fed MPMC had a greater netAUC than dogs fed HPLC and dogs fed MET tended to have a greater netAUC than HPLC. Dogs fed HPLC had greater concentrations of Ile, Leu, Lys, Thr, Tyr and Val over time compared to dogs fed MPMC and MET, and dogs fed MET had greater concentrations of Gln and Met over time compared to dogs fed HPLC and MPMC (P < 0.05). Dogs fed a HPLC diet may have improved glucose uptake compared to dogs fed a MPMC diet. This research provides the first insight into the cardiometabolic health of dogs consuming three diets differing in their protein, carbohydrate and fiber content.

Response of the gut microbiome and metabolome to dietary fiber in healthy dogs

Dietary fiber confers multiple health benefits originating from the expansion of beneficial gut microbial activity. However, very few studies have established the metabolic consequences of interactions among specific fibers, microbiome composition, and function in either human or representative animal models. In a study design reflective of realistic population dietary variation, fecal metagenomic and metabolomic profiles were analyzed from healthy dogs fed 12 test foods containing different fiber sources and quantities (5-13% as-fed basis). Taxa and functions were identified whose abundances were associated either with overall fiber intake or with specific fiber compositions. Fourteen microbial species were significantly enriched in response to ≥1 specific fiber source; enrichment of fiber-derived metabolites was more pronounced in response to these fiber sources. Positively associated fecal metabolites, including short-chain fatty acids, acylglycerols, fiber bound sugars, and polyphenols, co-occurred with microbes enriched in specific food groups. Critically, the specific metabolite pools responsive to differential fiber intake were dependent on differences both in individual microbial community membership and in overall ecological configuration. This helps to explain, for the first time, differences in microbiome-diet associations observed in companion animal epidemiology. Thus, our study corroborates findings in human cohorts and reinforces the role of personalized microbiomes even in seemingly phenotypically homogeneous subjects.

IMPORTANCE

Consumption of dietary fiber changes the composition of the gut microbiome and, to a larger extent, the associated metabolites. Production of health-relevant metabolites such as short-chain fatty acids from fiber depends both on the consumption of a specific fiber and on the enrichment of beneficial metabolite-producing species in response to it. Even in a seemingly homogeneous population, the benefit received from fiber consumption is personalized and emphasizes specific fiber-microbe-host interactions. These observations are relevant for both population-wide and personalized nutrition applications.

Replacement of Dietary Carbohydrate with Protein versus Fat Differentially Alters Postprandial Circulating Hormones and Macronutrient Metabolism in Dogs

The effect of dietary macronutrients on fasting and postprandial responses was examined. Thirty-six healthy dogs were fed a high-carbohydrate (HiCHO) food once daily for 5 weeks, followed by randomization to either a high-protein, low-carbohydrate (PROT_LoCHO) or high-fat, low-carbohydrate (FAT_LoCHO) food for 5 weeks, then crossed over to the other LoCHO food for 5 weeks. Plasma samples were obtained at the end of each feeding period at timepoints before (0 h) and 2 h post-feeding. Apparent total circulating energy availability was assessed as a summation of the energetic contributions of measured glucose, β-hydroxybutyrate, triglycerides (TGs), non-esterified fatty acids (NEFAs), and fatty acids not from TGs or NEFAs. In both the fed and fasted states, there were increases in circulating apparent total energy availability after feeding the FAT_LoCHO food compared with the HiCHO or PROT_LoCHO foods. Changes from the postabsorptive to postprandial points in catabolic, anabolic, and signaling lipids all exhibited food effects. Consumption of either LoCHO food led to lower leptin/ghrelin ratios in the fasted state relative to the HiCHO food. The FAT_LoCHO food led to the highest postprandial levels of the incretins gastric inhibitory peptide and glucagon-like peptide-1, yet the lowest increases in insulin relative to the other foods. These findings provide information on how macronutrients can influence dietary energy processing and metabolic health.

How Successful Are Veterinary Weight Management Plans for Canine Patients Experiencing Poor Welfare Due to Being Overweight and Obese?

Overweight and obesity is one of the most significant health and welfare issues affecting companion animals and are linked to several serious medical conditions, reduced welfare, and shortened lifespan. The number of overweight and obese pets increases every year. Overweight and obesity are associated with multiple chronic diseases. Underlying causes include human-related and animal-related factors. Veterinarians encounter overweight and obese canine patients in daily practice and they play an important role in weight management. This research examines the level of veterinary engagement and the success of veterinary management plans for overweight and obese canines over a five-year period. Electronic medical records (EMRs) were collected for 500 canine patients assessed as either overweight or obese and statistically analyzed for level of veterinary engagement (VE), weight loss success, prescription weight loss diet (RX) use, and comorbidities. The average age at the beginning of the study was 61.5 months. A starting Body Condition Score (BCS) of 6 or 7 was most common (87.2%). Twelve different small and large dog breeds were most highly represented (61.1%). Average weight loss rates were low and more dogs gained rather than lost weight (56.5% vs. 43.5%). While VE is important, this study suggests current VE levels are not adequate to successfully combat overweight and obesity or result in improved animal welfare.

Feeding of fish oil and medium-chain triglycerides to canines impacts circulating structural and energetic lipids, endocannabinoids, and non-lipid metabolite profiles

Introduction

The effect of medium-chain fatty acid-containing triglycerides (MCT), long-chain polyunsaturated fatty acid-containing triglycerides from fish oil (FO), and their combination (FO+MCT) on the serum metabolome of dogs (Canis familiaris) was evaluated.

Methods

Dogs (N = 64) were randomized to either a control food, one with 7% MCT, one with FO (0.18% eicosapentaenoate and 1.3% docosahexaenoate), or one with FO+MCT for 28 days following a 14-day washout period on the control food. Serum metabolites were analyzed via chromatography followed by mass spectrometry.

Results

Additive effects of serum metabolites were observed for a number of metabolite classes, including fatty acids, phospholipids, acylated amines including endocannabinoids, alpha-oxidized fatty acids, and methyl donors. Some effects of the addition of FO+MCT were different when the oils were combined compared with when each oil was fed separately, namely for acylcarnitines, omega-oxidized dicarboxylic acids, and amino acids. Several potentially beneficial effects on health were observed, including decreased circulating triglycerides and total cholesterol with the addition of FO (with or without MCT) and decreases in N-acyl taurines with the addition of MCT, FO, or FO+MCT.

Discussion

Overall, the results of this study provide a phenotypic characterization of the serum lipidomic response to dietary supplementation of long-chain n3-polyunsaturated and medium-chain saturated fats in canines.

Effects of weight loss and feeding specially formulated diets on the body composition, blood metabolite profiles, voluntary physical activity, and fecal metabolites and microbiota of obese dogs

Canine obesity negatively influences health and well-being, but can be managed by altering diet composition and caloric intake. Restricted feeding, dietary intervention, and consequent weight loss may be used to improve health and modify gastrointestinal microbiota. In this study, we aimed to determine the effects of restricted feeding of specially formulated foods on weight loss, body composition, voluntary physical activity, serum hormones and oxidative stress markers, and fecal metabolites and microbiota populations of obese dogs. Twenty-four obese dogs [body weight (BW) = 15.2 ± 1.7 kg; body condition score (BCS) = 8.7 ± 0.4; muscle condition score (MCS) = 3.5 ± 0.3; age = 7.2 ± 1.6 yr] were used in a 24-wk study. A control (OR) food was fed during a 4-wk baseline to identify intake needed to maintain BW. After baseline, dogs were allotted to one of two diets: OR or test (FT), and then fed to lose 1.5% BW/wk. Food intake, BW, BCS, and MCS were measured, blood and fecal samples were collected, DEXA scans were performed, and voluntary physical activity was measured over time. Microbiota data were evaluated using QIIME2 and change from baseline data from other measures were evaluated using the Mixed Models procedure of SAS, with P < 0.05 being significant. Restricted feeding led to reduced BW, BCS, fat mass, and blood cholesterol, triglyceride, glucose, and leptin concentrations, and increased MCS and lean body mass percentage. Blood cholesterol reduction was greater in dogs fed FT vs. OR. Fecal metabolites and bacterial alpha-diversity were affected by diet and weight loss. Dogs fed FT had greater reductions in fecal short-chain fatty acid, branched-chain fatty acid, and ammonia concentrations than those fed OR. Dogs fed OR had a higher alpha-diversity than those fed FT. Weight loss increased alpha-diversity (weeks 16, 20, and 24 > weeks 0 and 4). Beta-diversity showed separation between dietary groups and between week 0 and all other time points after week 8. Weight loss increased fecal Allobaculum and Ruminococcus torques. Weight loss also increased fecal Bifidobacterium, Faecalibaculum, and Parasutterella, but were greater in dogs fed OR. Weight loss decreased fecal Collinsella, Turicibacter, Blautia, Ruminococcus gnavus, Faecalibacterium, and Peptoclostridium, but were greater in dogs fed OR. In summary, restricted feeding promoted safe weight and fat loss, reduced blood lipid and leptin concentrations, and altered fecal microbiota of obese dogs.

The 13C-bicarbonate technique as a tool for measurement of energy expenditure in overweight dogs undergoing body weight reduction and the effect of different dietary composition

Changes in body size and composition, i.e., body weight (BW) gain or loss, affect the daily energy expenditure (EE). To ensure an appropriate BW reduction and to find an efficient strategy to reduce and maintain a target BW, regular evaluations and adjustments of energy allowance are important. This study aimed to provide a detailed knowledge about the possible changes in resting EE using the oral 13C-bicarbonate technique (o13CBT) as a research tool in 16 overweight pet dogs undergoing BW reduction. Dietary composition (i.e., in % of dry matter [DM] being a high protein [33.3], low fat [9.6], and high crude fiber [18.0] diet [LFHFibre], and a high protein [37.9], high fat [52.0], carbohydrate-free diet [HFat]) during 16 wk of energy restriction were evaluated regarding effects on resting EE, rate of BW reduction, body composition, and plasma concentrations of metabolic hormones involved in energy metabolism and appetite regulation. The mean BW loss was higher (P < 0.05) for the dogs fed the LFHFibre diet (1.1%/wk) than that for dogs fed the HFat diet (0.8%/wk), but the total BW reduction of 14.6% and 12.0% of initial BW did not differ significantly (P > 0.05). Resting EE was lower (P < 0.02) after the BW reduction; 414 kJ (99 kcal)/kg BW0.75/d at the start (week 0) and 326 kJ (78 kcal)/kg BW0.75/d at the end (week 16) of the study. The BW reduction in both groups (P > 0.05) consisted of both fat mass (FM) and fat-free mass (FFM). Energy expenditure, calculated in relation to amount of FFM, was not significantly (P > 0.05) affected by BW reduction. Dietary composition did not significantly affect (P > 0.05) plasma concentrations of insulin, leptin, and ghrelin, and no effect (P > 0.05) of BW reduction was observed on hormone concentrations. In conclusion, the o13CBT proved to be a useful research method for studying short-term EE in overweight dogs. Even though all dogs lost BW, most dogs were still overweight at the end of the study. Due to a high individual variation among dogs, a longer experimental period with a larger sample size would be desirable.

A Diet Supplemented with Polyphenols, Prebiotics and Omega-3 Fatty Acids Modulates the Intestinal Microbiota and Improves the Profile of Metabolites Linked with Anxiety in Dogs

Simple Summary

This study used a nutrition-based approach to examine the effects of foods supplemented with fish oil and a polyphenol blend (citrus pulp, carrot, and spinach) with or without added tomato pomace on anxiety-related biomarkers in dogs. First, all dogs consumed the same initial food, then either the control or test (with tomato pomace) foods, then the washout food, then switched over to the test or control foods, each for 30-day periods. Many more changes in plasma and fecal metabolites were observed when comparing the washout food with the control or test foods than when the control and test foods were compared. Plasma levels of several metabolites that were previously associated with anxiety disorders, including 4-ethylphenyl sulfate, were decreased with the control or test foods compared with the washout food. In addition, bacterial genera that are decreased in the feces of those with anxiety-like disorders were increased following the consumption of the control or test foods. Overall, these data indicate that foods supplemented with omega-3 fatty acids and selected fiber and polyphenol sources lead to beneficial changes in anxiety-related metabolites and gut bacteria.

Abstract

A nutrition-based approach was utilized to examine the effects of fish oil and a polyphenol blend (with or without tomato pomace) on the fecal microbiota and plasma/fecal metabolomes. Forty dogs, aged 5–14 years, were fed a washout food, then randomized to consume a control (fish oil and polyphenol blend without tomato pomace) or test (fish oil and polyphenol blend with tomato pomace) food, then the washout food, and crossed over to consume the test or control food; each for 30 days. Several metabolites differed when comparing consumption of the washout with either the control or test foods, but few changed significantly between the test and control foods. Plasma levels of 4-ethylphenyl sulfate (4-EPS), a metabolite associated with anxiety disorders, demonstrated the largest decrease between the washout food and the control/test foods. Plasma 4-EPS levels were also significantly lower after dogs ate the test food compared with the control food. Other plasma metabolites linked with anxiety disorders were decreased following consumption of the control/test foods. Significant increases in Blautia, Parabacteroides, and Odoribacter in the fecal microbiota correlated with decreases in 4-EPS when dogs ate the control/test foods. These data indicate that foods supplemented with polyphenols and omega-3 fatty acids can modulate the gut microbiota to improve the profile of anxiety-linked metabolites.

Macronutrient Proportions and Fat Type Impact Ketogenicity and Shape the Circulating Lipidome in Dogs

Many physiological processes including ketogenesis are similar in dogs and humans, but there is little information available on the effect of carbohydrate restriction in dogs. Here, the ketogenicity and serum metabolic profiles of dogs were assessed after they had consumed high carbohydrate (HiCHO); high protein, low carbohydrate (PROT_LoCHO); or high fat, low carbohydrate (FAT_LoCHO) foods. Thirty-six dogs were fed HiCHO for 4 weeks, then randomized to PROT_LoCHO or FAT_LoCHO for 5 weeks. Dogs then crossed over to the other food for an additional 5 weeks. Generally, reduction of dietary carbohydrate by replacement with either protein or fat increased the energy required to maintain body weight, and fat had a greater effect. Postabsorptive energy availability derived mainly from glucose and triglycerides with HiCHO, from gluconeogenic amino acids and fatty acids with PROT_LoCHO, and from fatty acids and β-hydroxybutyrate with FAT_LoCHO. This study demonstrated that the reduction of carbohydrate in canine foods is potentially beneficial to dogs based on improvements in metabolism and supports the use of low-carbohydrate foods as safe and effective for healthy adult dogs.

The Serum and Fecal Metabolomic Profiles of Growing Kittens Treated with Amoxicillin/Clavulanic Acid or Doxycycline

Simple Summary

This study investigated the impact of antibiotic treatment οn the serum and fecal metabolome (the collection of all small molecules produced by the gut bacteria and the host) of young cats. Thirty 2-month-old cats with an upper respiratory tract infection were treated with either amoxicillin/clavulanic acid for 20 days or doxycycline for 28 days. In addition, another 15 control cats that did not receive antibiotics were included. Blood was collected on days 0 (before treatment), 20/28 (last day of treatment), and 300 (10 months after the end of treatment), while feces were collected on days 0, 20/28, 60, 120, and 300. Seven serum and fecal metabolites differed between cats treated with antibiotics and control cats at the end of treatment period. Ten months after treatment, no metabolites differed from healthy cats, suggesting that amoxicillin/clavulanic acid or doxycycline treatment only temporarily affects the abundance of the serum and fecal metabolome.

Abstract

The long-term impact of antibiotics on the serum and fecal metabolome of kittens has not yet been investigated. Therefore, the objective of this study was to evaluate the serum and fecal metabolome of kittens with an upper respiratory tract infection (URTI) before, during, and after antibiotic treatment and compare it with that of healthy control cats. Thirty 2-month-old cats with a URTI were randomly assigned to receive either amoxicillin/clavulanic acid for 20 days or doxycycline for 28 days, and 15 cats of similar age were enrolled as controls. Fecal samples were collected on days 0, 20/28, 60, 120, and 300, while serum was collected on days 0, 20/28, and 300. Untargeted and targeted metabolomic analyses were performed on both serum and fecal samples. Seven metabolites differed significantly in antibiotic-treated cats compared to controls on day 20/28, with two differing on day 60, and two on day 120. Alterations in the pattern of serum amino acids, antioxidants, purines, and pyrimidines, as well as fecal bile acids, sterols, and fatty acids, were observed in antibiotic-treated groups that were not observed in control cats. However, the alterations caused by either amoxicillin/clavulanic acid or doxycycline of the fecal and serum metabolome were only temporary and were resolved by 10 months after their withdrawal.

Metabolic variables of obese dogs with insulin resistance supplemented with yeast beta-glucan

Background

Obesity is one of the most common nutritional disorders in dogs and cats and is related to the development metabolic comorbidities. Weight loss is the recommended treatment, but success is difficult due to the poor satiety control. Yeast beta-glucans are known as biological modifiers because of their innumerable functions reported in studies with mice and humans, but only one study with dogs was found. This study aimed to evaluate the effects of a diet supplemented with 0.1% beta-glucan on glucose, lipid homeostasis, inflammatory cytokines and satiety parameters in obese dogs. Fourteen dogs composed three experimental groups: Obese group (OG) with seven dogs with body condition score (BCS) 8 or 9; Lean group (LG) included seven non-obese dogs with a BCS of 5; and Supplemented Obese group (SOG) was the OG dogs after 90 days of consumption of the experimental diet.

Results

Compared to OG, SOG had lower plasma basal glycemic values (p = 0.05) and reduced serum cholesterol and triglyceride levels. TNF-α was lower in SOG than in OG (p = 0.05), and GLP-1 was increased in SOG compared to OG and LG (p = 0.02).

Conclusion

These results are novel and important for recognizing the possibility of using beta-glucan in obesity prevention and treatment.

Weight loss and high-protein, high-fiber diet consumption impact blood metabolite profiles, body composition, voluntary physical activity, fecal microbiota, and fecal metabolites of adult dogs

Canine obesity is associated with reduced lifespan and metabolic dysfunction, but can be managed by dietary intervention. This study aimed to determine the effects of restricted feeding of a high-protein, high-fiber (HPHF) diet and weight loss on body composition, physical activity, blood metabolites, and fecal microbiota and metabolites of overweight dogs. Twelve spayed female dogs (age: 5.5 ± 1.1 yr; body weight [BW]: 14.8 ± 2.0 kg, body condition score [BCS]: 7.9 ± 0.8) were fed a HPHF diet during a 4-wk baseline phase to maintain BW. After baseline (week 0), dogs were first fed 80% of baseline intake and then adjusted to target 1.5% weekly weight loss for 24 wk. Body composition using dual-energy x-ray absorptiometry and blood samples (weeks 0, 6, 12, 18, and 24), voluntary physical activity (weeks 0, 7, 15, and 23), and fresh fecal samples for microbiota and metabolite analysis (weeks 0, 4, 8, 12, 16, 20, and 24) were measured over time. Microbiota data were analyzed using QIIME 2. All data were analyzed statistically over time using SAS 9.4. After 24 wk, dogs lost 31.2% of initial BW and had 1.43 ± 0.73% weight loss per week. BCS decreased (P < 0.0001) by 2.7 units, fat mass decreased (P < 0.0001) by 3.1 kg, and fat percentage decreased (P < 0.0001) by 11.7% with weight loss. Many serum metabolites and hormones were altered, with triglycerides, leptin, insulin, C-reactive protein, and interleukin-6 decreasing (P < 0.05) with weight loss. Relative abundances of fecal Bifidobacterium, Coriobacteriaceae UCG-002, undefined Muribaculaceae, Allobaculum, Eubacterium, Lachnospira, Negativivibacillus, Ruminococcus gauvreauii group, uncultured Erysipelotrichaceae, and Parasutterella increased (P < 0.05), whereas Prevotellaceae Ga6A1 group, Catenibacterium, Erysipelatoclostridium, Fusobacterium, Holdemanella, Lachnoclostridium, Lactobacillus, Megamonas, Peptoclostridium, Ruminococcus gnavus group, and Streptococcus decreased (P < 0.01) with weight loss. Despite the number of significant changes, a state of dysbiosis was not observed in overweight dogs. Fecal ammonia and secondary bile acids decreased, whereas fecal valerate increased with weight loss. Several correlations between gut microbial taxa and biological parameters were observed. Our results suggest that restricted feeding of a HPHF diet and weight loss promotes fat mass loss, minimizes lean mass loss, reduces inflammatory marker and triglyceride concentrations, and modulates fecal microbiota phylogeny and activity in overweight dogs.

Dietary Fatty Acids Change Circulating Fatty Acids, Microbial Putrefactive Postbiotics and Betaine Status in the Cat

Simple Summary

The cat is an obligate carnivore that is well adapted to dietary polyunsaturated fatty acids (PUFA), perhaps because of the variance resulting from normal consumption of organ meat which is high in PUFA, and storage lipid which is often relatively low in PUFA. Although able to tolerate and thrive with this variation, cats have a metabolic response to fatty acids that is relatively unknown. This study shows that dietary PUFA resulted in changing circulating concentrations of that specific PUFA. Increasing dietary eicosapentaenoic acid EPA and docosahexaenoic acid DHA (E&D) resulted in little change in total circulating PUFA as compared to increasing dietary arachidonic acid (ARA) which resulted in an increased concentration of total circulating PUFA. Cats responded to increased dietary E&D by reducing circulating cholesterol as compared to control fed cats. Increasing dietary PUFA also resulted in a decrease in circulating betaine, dimethylglycine and sarcosine in comparison to the cats consuming the control food at the end of the study. Changing dietary PUFA also changed circulating concentrations of gut microbial purification postbiotics. Increasing dietary ARA resulted in an increased concentration of indoleacetate, indolepropionate and indoleacetylglutamine in comparison to cats fed foods enhanced with increased E&D. Increasing E&D resulted in a decreased concentration of 4-ethylphenylsulfate, 3-methyl catechol sulfate and 4-vinylphenol sulfate at the end of the feeding period as compared to cats fed increased ARA or fed the unsupplemented control food. These changes suggest that support of single carbon metabolism would benefit cats with increasing dietary PUFA, that increasing E&D beneficially lowered cholesterol and that dietary PUFA influenced gut microbes resulting in changes in their postbiotics.

Abstract

There is a normal variation of polyunsaturated fatty acids (PUFA) in the foods consumed both by the domestic cat and wild felines. This variation may lead to specific changes in metabolites and circulating fatty acids that influence health and response to disease. Therefore, in order to evaluate the response to these changes in dietary PUFA three foods were formulated: a complete and balanced control food (COF) with no enhanced source of added PUFA (ARA = 0.08%, EPA & DHA = 0.01%), Test food 1 (E&DF) like the COF with added eicosapentaenoic acid EPA and docosahexaenoic acid DHA (E&D = 0.36%)) from menhaden fish oil, and Test Food 2 (ARAF) like the COF with added arachidonic acid (ARA = 0.16%) from liver. All test foods had similar protein concentrations and similar vitamin and mineral concentrations while the PUFA supplemented foods had slightly higher fat concentrations. Cats (n = 36) were fed a pre-trial food for 28 days and then assigned to a group fed either the control, E&DF or ARAF for 56 days (12 cats per group). Blood samples were drawn and serum analyzed for fatty acids, albumin, urea, creatinine, cholesterol and triglycerides at the beginning of the study and after consuming the test foods for 28 and 56 days. Plasma was similarly analyzed for metabolomics. Increasing dietary E&D resulted in reduced cholesterol, betaine, dimethyl glycine, sarcosine and 4-ethylphenylsulfate. Increasing dietary ARA resulted in reduced betaine, dimethyl glycine and sarcosine and an increased concentration of indoleacetate, indolepropionate and indoleacetylglutamine. These data suggest a benefit of dietary single carbon metabolism support for cats supplemented with ARA or E&D. Moreover, the reduction in circulating cholesterol and triglycerides through dietary E&D supplementation could benefit cats with hyperlipidemia. Further research into the interrelationship between dietary PUFA and the gut microbe will benefit from the data showing that ARA increased specific positive postbiotics (i.e., indoleacetate, indolepropionate) while E&D supplementation showed the benefit of reducing some postbiotics which have been associated with reduced health (4-ethylphenylsulfate, 3-methyl catechol sulfate and 4-vinylphenol sulfate).

Use of Metabolomic Profiling to Understand Variability in Adiposity Changes Following an Intentional Weight Loss Intervention in Older Adults

Inter-individual response to dietary interventions remains a major challenge to successful weight loss among older adults. This study applied metabolomics technology to identify small molecule signatures associated with a loss of fat mass and overall weight in a cohort of older adults on a nutritionally complete, high-protein diet. A total of 102 unique metabolites were measured using liquid chromatography-mass spectrometry (LC-MS) for 38 adults aged 65-80 years randomized to dietary intervention and 36 controls. Metabolite values were analyzed in both baseline plasma samples and samples collected following the six-month dietary intervention to consider both metabolites that could predict the response to diet and those that changed in response to diet or weight loss.Eight metabolites changed over the intervention at a nominally significant level: D-pantothenic acid, L-methionine, nicotinate, aniline, melatonin, deoxycarnitine, 6-deoxy-L-galactose, and 10-hydroxydecanoate. Within the intervention group, there was broad variation in the achieved weight-loss and dual-energy x-ray absorptiometry (DXA)-defined changes in total fat and visceral adipose tissue (VAT) mass. Change in the VAT mass was significantly associated with the baseline abundance of α-aminoadipate (p = 0.0007) and an additional mass spectrometry peak that may represent D-fructose, myo-inositol, mannose, α-D-glucose, allose, D-galactose, D-tagatose, or L-sorbose (p = 0.0001). This hypothesis-generating study reflects the potential of metabolomic biomarkers for the development of personalized dietary interventions.

Docosahexaenoate-enriched fish oil and medium chain triglycerides shape the feline plasma lipidome and synergistically decrease circulating gut microbiome-derived putrefactive postbiotics

The purpose of this study was to examine the influence of medium-chain fatty acid-containing triglycerides (MCT), long-chain polyunsaturated fatty acid-containing triglycerides, and their combination on the plasma metabolome of cats (Felis catus), including circulating microbiome-derived postbiotics. After a 14-day lead-in on the control food, cats were randomized to one of four foods (control, with 6.9% MCT, with fish oil [FO; 0.14% eicosapentaenoate, 1.0% docosahexaenoate], or with FO+MCT; n = 16 per group) for 28 days. Analysis of plasma metabolites showed that the addition of FO and MCT led to synergistic effects not seen with either alone across a number of lipid classes, including fatty acids, acylcarnitines, and acylated amines including endocannabinoids. Notably, the FO+MCT group had an increase in ketone body production relative to baseline and beyond that seen with MCT alone. N-acyl taurines, the accumulation of which has been implicated in the onset of type 2 diabetes, were significantly decreased in the FO+MCT group. Significant decreases in the gut microbiome-derived postbiotic classes of indoles/indolic sulfates and phenols/phenolic sulfates were observed only the FO+MCT group. Overall, the combination of MCT and FO led to number of changes in plasma metabolites that were not observed with either oil alone, particularly in postbiotics.

Organic matter disappearance and production of short- and branched-chain fatty acids from selected fiber sources used in pet foods by a canine in vitro fermentation model1

Dietary fibers can influence a dog’s overall health, but high concentrations of soluble dietary fibers can cause soft stools. An in vitro model could be useful to predict the rate fibers are fermented once they reach the colon. Pet food companies are constantly searching for new ingredients to differentiate their products from competitors. Miscanthus grass (MG), pea fiber (PF), and sorghum bran (SB) are novel fiber sources that could be alternatives to standards like cellulose (CE) and beet pulp (BP). The objectives of the study were to determine the effects of fiber source on organic matter disappearance (OMD), estimated organic matter disappearance (EOMD), and fermentation end-product concentrations using an in vitro fermentation procedure and dog fecal inoculum. Total dietary fiber (TDF) residues from MG, CE, BP, PF, and SB were fermented in vitro with buffered dog feces. Fecal samples were collected and maintained in anaerobic conditions until the dilution and inoculation. Test tubes containing the fibrous substrates were incubated for 4, 8, and 12 h at 39 °C. Short-chain fatty acids (SCFA), branched-chain fatty acids (BCFA), OMD, and EOMD were determined for each fiber source and time point. Beet pulp had the highest OMD, EOMD, and SCFA production of all tested fiber sources (38.6% OMD, 26.2% EOMD, 2.72 mmol SCFA/g of substrate). Sorghum bran led to greater concentrations of BCFA (59.86 µmol/g of substrate) and intermediate OMD and EOMD compared to the other tested fibers. Cellulose and MG were poorly fermented with the lowest OMD, EOMD, SCFA, and BCFA compared to other fibers. In conclusion, MG could be used as an insoluble minimally fermentable replacement fiber for CE in dog foods.

Factors associated with failure of dog's weight loss programmes

BACKGROUND

Canine obesity is the cause of several health issues, and may predispose other diseases, such as orthopaedic disorders, endocrinopathies, metabolic abnormalities and cardiorespiratory disease which can lead to a decreased quality of life and reduced lifespan. Dog are considered overweight when their body weight is ≥15% above their ideal body weight, and as obese when their body weight exceeds 30% of optimal. Prevalence of canine obesity is estimated to be around 5%-20%, and up to 30%-40% when all overweight dogs are considered. Treatment is based on weight loss programmes, focused on caloric restriction associated with exercise. However, success rate of treatment is low.

OBJECTIVES

The aim of this study was to investigate the reasons for weight loss failure of obese dogs during treatment with low-calorie diets.

METHODS

Records of obese dogs undergoing weight loss programmes between May 2014 and May 2017, assessed by a team specialized in veterinary nutrition, were retrospectively evaluated. Dogs were classified according to weekly weight loss rate (WWLR) (<1%, between 1% and 2%, and more than 2%) and owner compliance with a dietary prescription and physical activity recommendations.

RESULTS

The mean WWLR was not satisfactory (<1%) in 64.4% (n = 47/73) of dogs. Regarding owner compliance with the dietary prescription, 44.7% (n = 21/47) of owners did not follow diet prescriptions and physical activity recommendations for their dogs. There was a significant association (p = .01) between compliance of owners and satisfactory weight loss rate; however, there was no association between weight loss success, diet composition sex, reproductive status, age of the dogs and their physical activity (p ≥ .05).

CONCLUSIONS

Non-compliance represents a great challenge in the treatment of canine obesity, and may be of more importance than other aspects.

Comparison of the effects of different kibble shape on voluntary food intake and palatability of weight loss diets in pet dogs

Altering characteristics of a dry proprietary diet can increase chewing, slow ingestion speed and reduce voluntary food intake. Panels of healthy research dogs consumed kibbled weight loss diets with either a l round (pastille) or a cross shape. Two panels ('small-size' panel, dogs<10 kg 'all-size' panel, dogs with a range of sizes) were used to determine palatability (study 1), whilst a third panel ('consumption kinetics panel') was used to determine voluntary food intake [VFI] and meal duration (study 2). Study 3 was a field trial where the cross kibble was fed to client-owned overweight dogs undergoing controlled weight loss, and attitudes of owners were sort. In study 1, dogs in the all-size panel consumed more of the cross-kibble diet than of the round-kibble diet (P < .001), but there was no significant difference in dogs of the small-size panel (P = 1.000). In study 2, VFI was broadly similar for both diets, with no difference in total consumption across all four meals (P = .370). However, meal duration was significantly longer for the cross kibble (meal 1: 292 s; meal 2: 650 s) compared with the round kibble (meal 1: 186 s; meal 2: 282, P < .001 for both). In study 3, owners observed more chewing behaviour (P = .031), slower ingestion speed (P = .031), and a significant decrease in food-seeking behaviour (P = .020) when eating the cross-kibble compared with the round-kibble. Altering the kibble shape of a canine therapeutic weight loss diet can decrease ingestion speed without affecting palatability, but studies are now required to determine the effect on outcomes of weight management.

Balance of saccharolysis and proteolysis underpins improvements in stool quality induced by adding a fiber bundle containing bound polyphenols to either hydrolyzed meat or grain-rich foods

Dietary fiber is a key component in gastrointestinal health maintenance partly due to its fermentation by the gut microbiome. The food-dependent effects of a novel fiber bundle added to hydrolyzed meat (HM) or grain-rich (GR) foods in healthy dogs (n = 16) or those with chronic enteritis/gastroenteritis (n = 16) were examined. Addition of fiber to either food improved stool quality in dogs regardless of health status; microbiome diversity of dogs with chronic enteritis/gastroenteritis became more similar to healthy dogs. The abundance of bacteria mediating beneficial saccharolytic processes (eg, Lachnospiraceae) significantly increased on addition of fiber to the GR food, while those mediating detrimental proteolytic catabolism (eg, Desulfovibrionaceae) significantly decreased. Fiber addition to the HM food led to significant changes in saccharolytic/proteolytic bacteria. Higher levels of free saccharides in feces upon fiber addition to either food indicated increased saccharolysis. Fiber addition to the GR food decreased levels of fecal free amino acids, indicating decreased proteolysis. Addition of fiber decreased fecal pH for both foods but likely by different mechanisms: addition of fiber to the HM food led to increased straight-chain short-chain fatty acids (SCFAs) and no significant change in proteolytic branched-chain SFCAs, while in the GR food, fiber mainly led to decreased proteolytic branched-chain SFCAs. Other postbiotics related to intestinal health were consistently altered when fiber was added to either food. Plant-derived bioactive molecules were enriched in feces from dogs fed either food with added fiber, which could account for the observed modulation of the canine gut microbiome and shifts in metabolic capacity.

How effective are interventions designed to help owners to change their behaviour so as to manage the weight of their companion dogs? A systematic review and meta-analysis

OBJECTIVE

The present review sought to evaluate whether - and to what extent - targeting owners' behaviour is an effective way to reduce the problem of overweight and obesity among companion dogs.

METHODS

A systematic search of electronic databases identified 14 studies that evaluated the effect of an intervention targeting owners' behaviour on (i) the owner's behaviour or (ii) the weight, (iii) body fat, or (iv) body condition of the dog. We coded aspects of the study design (e.g., the outcome variable), intervention (e.g., use of theory, specific behaviour change techniques or BCTs, inclusion of nutritional intervention alongside the behavioural intervention), and sample (e.g., age, gender, and weight of the dogs at baseline) that could influence the effect sizes.

RESULTS

The interventions had, on average, a medium sized effect on outcomes (d₊ = 0.59, 95% CI: 0.23 to 0.96, k = 14, N = 384). The effect sizes from the primary studies were relatively homogenous, Q(13) = 12.10, p =  .52 and the nature of the intervention, methodological and sample characteristics did not moderate the effect sizes.

CONCLUSIONS AND CLINICAL RELEVANCE

The findings of the review suggest that targeting owners' behaviour can be an effective way to reduce overweight and obesity among companion dogs. However, this conclusion is based on a limited number of studies and so we hope that the present findings serve as the impetus for further research in this area.

Investigating owner use of dietary supplements in dogs with idiopathic epilepsy

Epilepsy is the most common chronic neurological disorder in dogs. Some diets have been shown to have a positive impact upon the seizure activity in dogs with idiopathic epilepsy (IE), while other diets and dietary supplements (DS), although marketed as providing health benefits, lack conclusive scientific evidence on their actual beneficial effects. A web-based owner questionnaire was designed to assess how and why owners of dogs with IE use different dietary regimes and DS. The study cohort, with 297 valid responses, consisted mainly of pure-breed (82.5%) male neutered (52.9%) dogs. Over two-thirds of owners (67.7%) changed their dog's diet after their dog received a diagnosis of IE. Nearly half of the owners (45.8%) reported giving DS, the most common being coconut oil or derived medium-chain triglyceride oil (71.3%). Some owner justifications of DS use included improvement of seizure frequency (88.2%), seizure severity (61.8%) and protection from potential drug side effects (62.5%). Many owners give DS to their dog with IE. The pharmacokinetic properties of anti-epileptic drugs, such as efficacy, absorption and clearance can be influenced by other medications, diets and possibly by DS. We propose that use of DS should be considered and monitored by veterinary surgeons in epilepsy management.

Success of a weight loss plan for overweight dogs: The results of an international weight loss study

INTRODUCTION

Obesity is a global concern in dogs with an increasing prevalence, and effective weight loss solutions are required that work in different geographical regions. The main objective was to conduct an international, multi-centre, weight loss trial to determine the efficacy of a dietary weight loss intervention in obese pet dogs.

METHODS

A 3-month prospective observational cohort study of weight loss in 926 overweight dogs was conducted at 340 veterinary practices in 27 countries. Commercially available dry or wet weight loss diets were used, with the initial energy allocation being 250-335 kJ/kg target body weight0.75/day (60-80 kcal/kg target body weight0.75/day) depending on sex and neuter status. The primary outcome measure was percentage weight loss; the main secondary outcomes were changes in activity, quality of life, and food-seeking behaviour, which were subjectively determined from owner descriptions.

RESULTS

At baseline, median (range) age was 74 (12 to 193) months and median body condition score was 8 (range 7-9). 896 of the 926 dogs (97%) lost weight, with mean weight loss being 11.4 ±5.84%. Sexually intact dogs lost more weight than neutered dogs (P = 0.001), whilst female dogs lost more weight than male dogs (P = 0.007), with the difference being more pronounced in North and South American dogs (median [Q1, Q3]: female: 11.5% [8.5%, 14.5%]; male: 9.1% [6.3%, 12.1%], P = 0.053) compared with those from Europe (female: 12.3% [8.9%, 14.9%]; male: 10.9% [8.6%, 15.4%]). Finally, subjective scores for activity (P<0.001) and quality of life (P<0.001) increased sequentially, whilst scores for food-seeking behaviour decreased sequentially (P<0.001) during the study.

CONCLUSION

This is the largest international multi-centre weight loss study conducted to date in obese dogs. Most dogs lost a clinically significant amount of weight, although there were notable differences between dogs of different sex, neuter status and in different geographical locations.

Comparison of voluntary food intake and palatability of commercial weight loss diets in healthy dogs and cats

Background

Obesity in dogs and cats is usually managed by dietary energy restriction using a purpose-formulated weight loss diet, but signs of hunger and begging commonly occur causing poor owner compliance. Altering diet characteristics so as to reduce voluntary food intake (VFI) can improve the likelihood of success, although this should not be at the expense of palatability. The aim of the current study was to compare the VFI and palatibility of novel commercially available canine and feline weight loss diets.

Methods

The relative performance of two canine (C1 and C2) and two feline (F1 and F2) diets was assessed in groups of healthy adult dogs and cats, respectively. Diets varied in energy, protein, fibre, and fat content. To assess canine VFI, 12 (study 1) and 10 (study 2) dogs were offered food in 4 meals, for 15 min on each occasion, with hourly intervals between the meals. For feline VFI, 12 cats were offered food ad libitum for a period of 18 h per day over 5 consecutive days. The palatability studies used separate panels of 37 dogs and 30 cats, with the two diets being served, side-by-side, in identical bowls.

Results

In dogs, VFI was significantly less for diet C1 than diet C2 when assessed on energy intake (study 1, 42% less, P = 0.032; study 2, 28% less, P = 0.019), but there was no difference in gram weight intake (study 1: P = 0.964; study 2: P = 0.255). In cats, VFI was 17% less for diet F1 than diet F2 when assessed by energy intake (P < 0.001), but there was again no difference in gram weight (P = 0.207). There was no difference in palatability between the two canine diets (P = 0.490), whilst the panel of cats diet preferred F1 to F2 (P < 0.001).

Conclusion

Foods with different characteristics can decrease VFI without affecting palatability in both dogs and cats. The effects seen could be due to decreased energy content, decreased fat content, increased fibre content, different fibre source, and increased protein content. Further studies are now needed to determine whether similar findings occur in obese dogs and cats on controlled weight loss programmes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-016-0899-x) contains supplementary material, which is available to authorized users.

Weight management in obese pets: the tailoring concept and how it can improve results

Obesity is now recognised as the most important medical disease in pets worldwide. All current strategies for weight management involve dietary energy restriction with a purpose-formulated diet. Whilst current weight management regimes can be successful, outcomes are often disappointing with the rate of weight loss progressively slowing down as time goes on. Success is most challenging for the most obese dogs and cats that are more likely to discontinue the programme before reaching target weight. To improve outcomes, clinicians must focus carefully on better tailoring programmes, paying particular to setting an appropriate target weight so as to maximise the benefits for the individual. In this opinionated review, the author will discuss findings from recent clinical research studies examining weight management in obese dogs and cats. A strategy for tailoring weight management targets will then be discussed, illustrated with case examples.

Obesity Prevention and Weight Maintenance After Loss

Obesity is one of the most prevalent medical diseases in pets. Outcomes are often disappointing; many animals either fail to reach target weight or regain weight. This article discusses managing obesity, focusing on prevention. It gives guidance on establishing monitoring programs that use regular body weight and condition assessments to identify animals at risk of inappropriate weight gain, enabling early intervention. Weight management in obese animals is a lifelong process. Regular weight and body condition monitoring are key to identifying animals that rebound early, while continuing to feed a therapeutic weight loss diet can help prevent it from happening.

Outcomes of weight management in obese pet dogs: what can we do better?

Obesity is arguably the biggest health and welfare issue affecting pet dogs. Although successful weight loss has health benefits, current strategies are far from ideal. Many obese dogs that start a weight programme fail to lose weight, or subsequently regain the weight they have lost. Given that current weight loss strategies are not perfect, clinicians need to focus carefully on tailoring the programme, perhaps setting a pragmatic target for weight loss, so as to ensure the benefits are maximised. This review will summarise key findings from recent clinical research into pet obesity, and present a framework for improving success, by better tailoring weight management regimens and end points to the individual.