Dietary intake of amino acids and vitamins compared to NRC requirements in obese cats undergoing energy restriction for weight loss

High starch intake favours body weight control in neutered and spayed cats living in homes fed ad libitum

Different starch-to-protein ratios were compared among neutered and spayed domiciled cats. Male and female obese and non-obese cats were fed kibble diets ad libitum for 4 months high in starch (HS (38 % crude protein (CP)): starch 32 %, protein 38 %; DM basis) or high in protein (HP (55 % CP): starch 19 %, protein 55 %) but similar in energy and fat in a crossover design. Physical activity was evaluated using an accelerometer, and body composition (BC), energy expenditure (EE) and water turnover (WT) using the doubly labelled water method. Results were compared in a 2 diet × 2 sex × 2 body condition factorial arrangement. Cats fed the HS (38 % CP) diet maintained a constant body weight, but lean mass (LM) tended to be reduced in female obese but to be increased in male non-obese (P < 0·08) and increased in female non-obese cats (P = 0·01). The HP (55 % CP) diet induced an increase in cat body weight and LM (P < 0·05) without altering BC proportion. EE tended to be higher in males (351 (se 8) kJ/kg0·67/d) than females (330 (se 8) kJ/kg0·67/d; P = 0·06), was unaffected by diet or BC, decreased as age increased (R 2 0·44; P < 0·01) and increased as physical activity increased (R 2 0·58; P < 0·01). WT was higher for the HP (55 % CP) diet (P < 0·01) and increased with EE (R 2 0·65; P < 0·01). The HS (38 % CP) diet favoured body weight control during 4 months of ad libitum feeding. Caution is necessary to balance protein in diets of female obese cats over 5 years, as they may have low energy and food intake, with LM loss.

Description of the fasted serum metabolomic signature of lean and obese cats at maintenance and of obese cats under energy restriction

This study aimed to investigate the serum metabolomic profile of obese and lean cats as well as obese cats before and after energy restriction for weight loss. Thirty cats, 16 obese (body condition score 8 to 9/9) and 14 lean (body condition score 4 to 5/9), were fed a veterinary weight loss food during a 4-week period of weight maintenance (L-MAINT and O-MAINT). The 16 obese cats were then energy restricted by a 60% energy intake reduction with the same food for a 10-week period (O-RESTRICT). Fasted serum metabolites were measured using nuclear magnetic resonance and direct infusion mass spectrometry after the maintenance period for L-MAINT and O-MAINT cats and after the energy restriction period for O-RESTRICT and compared between groups using a two-sided t-test. Obese cats lost 672 g ± 303 g over the 10-week restriction period, representing a weight loss rate of 0.94 ± 0.28% per week. Glycine, l-alanine, l-histidine, l-glutamine, 2-hydroxybutyrate, isobutryric acid, citric acid, creatine, and methanol were greater in O-RESTRICT compared to O-MAINT. There was a greater concentration of long-chain acylcarnitines in O-RESTRICT compared to both O-MAINT and L-MAINT, and greater total amino acids compared to O-MAINT. Glycerol and 3-hydroxybutyric acid were greater in O-MAINT compared to L-MAINT, as were several lysophosphatidylcholines. Thus, energy restriction resulted in increased dispensable amino acids in feline serum which could indicate alterations in amino acid partitioning. An increase in lipolysis was not evident, though greater circulating acylcarnitines were observed, suggesting that fatty acid oxidation rates may have been greater under calorie restriction. More research is needed to elucidate energy metabolism and substrate utilization, specifically fatty acid oxidation and methyl status, during energy restriction in strict carnivorous cats to optimize weight loss.

Identifying the target population and preventive strategies to combat feline obesity

Feline obesity continues to be a priority health and welfare issue. Most research surrounding obesity currently focuses on obesity treatment. However, treatment for feline obesity is slow, often unsuccessful and not without consequences. Identifying high-risk populations for obesity onset is crucial for developing and implementing preventive strategies. This review identifies post-gonadectomy kittens aged 5-12 months as the primary target population for obesity prevention in domestic cats and highlights dietary and feeding management strategies to be implemented for obesity prevention.

Beyond the Bowl: Understanding Amino Acid Requirements and Digestibility to Improve Protein Quality Metrics for Dog and Cat Foods

The determination of amino acid (AA) requirements for mammals has traditionally been done through nitrogen (N) balance studies, but this technique underestimates AA requirements in adult animals. There has been a shift toward researchers using the indicator amino acid oxidation (IAAO) technique for the determination of AA requirements in humans, and recently in dogs. However, the determination of AA requirements specific to adult dogs and cats at maintenance is lacking and the current requirements outlined by the National Research Council are based on a dearth of data and are likely underreporting the requirements of indispensable AA (IAA) for the population. To ensure the physiological requirements of our cats and dogs are met, we need methods to accurately and precisely measure digestibility. In vivo methods, such as ileal cannulation, are most commonly used, however, due to ethical considerations, we are moving away from animal models and toward in vitro methods. Harmonized static digestion models have the potential to replace in vivo methods but work needs to be done to have these methods more accurately represent the gastrointestinal tract (GIT) of cats and dogs. The Digestible IAA Score (DIAAS) is one metric that can help define protein quality for individual ingredients or mixed diets that uses AA SID estimates and ideally those can be replaced with in vitro AA digestibility estimates. Finally, we need accurate and reliable laboratory AA analyses to measure the AA present in complete diets, especially those used to quantify methionine (Met) and cysteine (Cys), both often limiting AAs in cat and dog diets. Together, this will guide accurate feed formulation for our companion animals to satisfy requirements while avoiding over-supplying protein, which inevitably contributes to excess N excretion, affecting both the environment and feed sustainability.

Partial weight reduction protocols in cats lead to better weight outcomes, compared with complete protocols, in cats with obesity

Background

To date, there have been no studies comparing outcomes of cats with obesity following either complete or partial weight reduction protocols.

Methods

Fifty-eight cats participated in this non-randomized observational cohort study, including 46 (79%) and 12 (21%) that underwent complete or partial weight reduction protocols, respectively. Weight loss outcomes, body composition changes and essential nutrient intake were compared between cats in the two groups.

Results

All cats remained healthy, and those on a complete weight reduction protocol lost a median of 23% (range 10-39%) of starting body weight (SBW) over 294 days (113-967 days), whereas those undergoing partial restriction lost 25% (10-41%) over 178 days (54-512 days). Neither duration nor percentage weight loss differed between groups, but those that followed a partial weight reduction protocol lost weight at a faster rate (0.81% per week) and required fewer visits (4-19) than those that followed a complete weight reduction protocol (0.61% per week, p = 0.028; 11, 4-40 visits, p = 0.009). Further, lean tissue mass declined in cats on a complete weight reduction protocol (pre: 4.20 kg, 2.64-5.72 kg; post: 3.90 kg, 2.76-5.24 kg, p < 0.001), whereas lean tissue mass was unchanged in cats on partial weight reduction protocols (pre: 3.45 kg, 2.79-4.71 kg; post: 3.41 kg, 2.90-4.59 kg, p = 0.109). In 33 (57%) cats, median intake of selenium per day was less than NRC AI and RA recommendations, whilst intake was under FEDIAF recommendation in 42 (72%) cats. Median intake of choline per day was less than NRC MR and RA recommendations in 22 (38%) and 53 (91%) cats, respectively, whereas it was under the FEDIAF recommendation in 51 (88%) cats. In a small proportion (12-14%) of cats, phenylalanine/tyrosine and potassium were under recommendations; besides these, no other essential nutrient deficiencies were seen, and there were no differences between cats undergoing complete and partial weight reduction.

Conclusion

Partial weight reduction protocols in cats lead to quicker average weight loss, with the possibility that lean tissue loss might be minimized. Such protocols might be more suitable for older cats and those with marked obesity.

The Pulse of It: Dietary Inclusion of Up to 45% Whole Pulse Ingredients with Chicken Meal and Pea Starch in a Complete and Balanced Diet Does Not Affect Cardiac Function, Fasted Sulfur Amino Acid Status, or Other Gross Measures of Health in Adult Dogs

BACKGROUND

Pulses are an attractive alternative protein source for all mammals; however, recent reports suggest that these ingredients may be related to developing dilated cardiomyopathy in dogs.

OBJECTIVES

The primary objective of this study was to quantify the effects of dietary pulse intake by adult dogs on cardiac function using echocardiographic measurements and cardiac biomarkers N-terminal pro-B-type natriuretic peptide and cardiac troponin I (cTnI). Second, to investigate the effects of pulse consumption on plasma sulfur amino acid (SAA) concentrations as pulses are generally low in SAA and may limit taurine synthesis. Last, to assess the general safety and efficacy of feeding pulse-containing diets on canine body composition and hematological and biochemical indices.

METHODS

Twenty-eight privately-owned domestic Siberian Huskies (13 females; 4 intact, and 15 males; 6 intact) with a mean age of 5.3 ± 2.8 y (± SD) were randomly assigned to 1 of 4 dietary treatments (n = 7/treatment), with equal micronutrient supplementation and increasing whole pulse ingredient inclusion (0%, 15%, 30%, and 45%) with pea starch used to balance protein and energy.

RESULTS

After 20 wks of feeding, there were no differences (P > 0.05) in echocardiographic parameters, N-terminal pro-B-type natriuretic peptide, and cTnI concentrations among treatments or across time within treatment (P > 0.05), indicating no differences in cardiac function among treatments. Concentrations of cTnI remained below the safe upper limit of 0.2 ng/mL for all dogs. Plasma SAA status, body composition, and hematological and biochemical indices were similar among treatments and over time (P > 0.05).

CONCLUSIONS

The results from this study suggest that increasing the inclusion of pulses up to 45% with the removal of grains and equal micronutrient supplementation does not impact cardiac function concurrent with dilated cardiomyopathy, body composition, or SAA status and is safe for healthy adult dogs to consume when fed for 20 wks.

Different Diet Energy Levels Alter Body Condition, Glucolipid Metabolism, Fecal Microbiota and Metabolites in Adult Beagle Dogs

Diet energy is a key component of pet food, but it is usually ignored during pet food development and pet owners also have limited knowledge of its importance. This study aimed to explore the effect of diet energy on the body condition, glucolipid metabolism, fecal microbiota and metabolites of adult beagles and analyze the relation between diet and host and gut microbiota. Eighteen healthy adult neutered male beagles were selected and randomly divided into three groups. Diets were formulated with three metabolizable energy (ME) levels: the low-energy (Le) group consumed a diet of 13.88 MJ/kg ME; the medium-energy (Me) group consumed a diet of 15.04 MJ/kg ME; and the high-energy (He) group consumed a diet of 17.05 MJ/kg ME. Moreover, the protein content of all these three diets was 29%. The experiment lasted 10 weeks, with a two-week acclimation period and an eight-week test phase. Body weight, body condition score (BCS), muscle condition score (MCS) and body fat index (BFI) decreased in the Le group, and the changes in these factors in the Le group were significantly higher than in the other groups (p < 0.05). The serum glucose and lipid levels of the Le and He groups changed over time (p < 0.05), but those of the Me group were stable (p > 0.05). The fecal pH of the Le and He groups decreased at the end of the trial (p < 0.05) and we found that the profiles of short-chain fatty acids (SCFAs) and bile acids (BAs) changed greatly, especially secondary BAs (p < 0.05). As SCFAs and secondary BAs are metabolites of the gut microbiota, the fecal microbiota was also measured. Fecal 16S rRNA gene sequencing found that the Me group had higher α-diversity indices (p < 0.05). The Me group had notably higher levels of gut probiotics, such as Faecalibacterium prausnitzii, Bacteroides plebeius and Blautia producta (p < 0.05). The diet-host-fecal microbiota interactions were determined by network analysis, and fecal metabolites may help to determine the best physical condition of dogs, assisting pet food development. Overall, feeding dogs low- or high-energy diets was harmful for glucostasis and promoted the relative abundance of pathogenic bacteria in the gut, while a medium-energy diet maintained an ideal body condition. We concluded that dogs that are fed a low-energy diet for an extended period may become lean and lose muscle mass, but diets with low energy levels and 29% protein may not supply enough protein for dogs losing weight.

Circulating direct infusion MS and NMR metabolomic profiles of post-gonadectomy kittens with or without additional dietary choline supplementation

Choline is beneficial for energy metabolism and growth in various species. Choline may work similarly in kittens at risk of obesity. Direct infusion MS (Di-MS) and NMR spectroscopy were used to investigate the metabolomic signatures of kittens supplemented with or without additional dietary choline for 12 weeks. Fifteen intact male kittens consumed a base diet (3310 mg choline/kg DM) to their daily metabolisable energy requirement (DER) over an 11-week acclimation. Kittens were gonadectomised and assigned, based on body weight, to the base diet (CONTROL, n 7) or the base diet with 300 mg/kgBW0·75 additional choline as choline chloride (CHOLINE, n 8) and offered three times their individual energy requirement divided into three meals. At weeks −1 and 12, fasted blood was sampled and serum analysed for 130 metabolites via Di-MS and fifty-one metabolites via NMR spectroscopy. Changes in fasted metabolites were assessed using a repeated-measures GLIMMIX procedure with time and group as fixed effects, and time as a repeated measure. Metabolites of one-carbon metabolism and lipids increased, and medium-chain acyl carnitines decreased from week −1 to 12 for CHOLINE (P < 0·05), but not CONTROL (P > 0·05). Increases in amino acid, biogenic amine and organic compound concentrations were observed in both groups (P < 0·05). The results suggest impacts of dietary choline at greater intakes than currently recommended on one-carbon metabolism and fatty acid oxidation, and these may promote healthy growth in post-gonadectomy kittens.

Jog with your dog: Dog owner exercise routines predict dog exercise routines and perception of ideal body weight

Canine obesity is becoming an increasingly prevalent concern among companion animal veterinarians and professionals alike. A number of sociodemographic, dietary, and exercise related variables have been shown to be predictive of a dog’s bodyweight, however, all previous surveys designed to address these variables have been focussed on only one area of the world at a time. The objective of this survey was to investigate how an owner’s exercise routine influences their dog’s exercise routine and which of the owner’s dietary and exercise habits influence their perception of their dog’s body weight. The survey included respondents across France, Germany, the United Kingdom, Canada and the United States. The survey was distributed online via Qualtrics (Qualtrics XM, Utah, USA) and a total of 3,298 responses were collected, equally distributed across country and between sexes. Comparison of column proportions and multinomial logistic regression were performed in SPSS Statistics (Version 26, IBM Corp, North Castle, New York, USA). Respondents from Germany were more likely to exercise their dog for a longer amount of time, rank the importance of exercise as extremely important, report that their dog is an ideal body weight, and were less likely to report that someone (including a veterinarian) had told them their dog was overweight. Results from linear regression revealed that those who had been told their dog was overweight, those who restrict their dog’s food intake to control weight, those who select a weight control diet and those who give their dog more other foods (treats, table scraps, fruits/vegetables) on a daily basis were all less likely to believe that their dog is an ideal body weight. In contrast, only those who reported doing more vigorous exercise themselves or those who reported that their dog performs vigorous exercise were more likely to believe that their dog is an ideal body weight. The results highlight owner’s perceptions of healthy weight and the role of nutrition and exercise. Owner’s intentions and attitudes towards the value of exercise and promoting an ideal body weight in their dog should be explored, but may require a One Health approach to ensure successful weight management among both dogs and their owners.

Serum Lipid, Amino Acid and Acylcarnitine Profiles of Obese Cats Supplemented with Dietary Choline and Fed to Maintenance Energy Requirements

Obesity is a health concern for domestic cats. Obesity and severe energy restriction predispose cats to feline hepatic lipidosis. As choline is linked to lipid metabolism, we hypothesized that dietary choline supplementation would assist in reducing hepatic fat through increased lipoprotein transport and fatty acid oxidation. Twelve obese cats (body condition score [BCS] ≥ 8/9) were split into two groups. Cats were fed a control (n = 6; 4587 mg choline/kg dry matter [DM]) or a high choline diet (n = 6; 18,957 mg choline/kg DM) for 5 weeks, for adult maintenance. On days 0 and 35, fasted blood was collected, and the body composition was assessed. Serum lipoprotein and biochemistry profiles, plasma amino acids and plasma acylcarnitines were analyzed. The body weight, BCS and body composition were unaffected (p > 0.05). Choline increased the serum cholesterol, triacylglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol and plasma methionine (p < 0.05) and decreased the serum blood urea nitrogen and alkaline phosphatase (p < 0.05). Choline also reduced the plasma acylcarnitine to free carnitine ratio (p = 0.006). Choline may assist in eliminating hepatic fat through increased fat mobilization and enhanced methionine recycling.