Obese Cats Research Articles

Restricted Feeding Of Weight Control Diets Induces Weight Loss And Affects Body Composition, Voluntary Physical Activity, Blood Metabolites, Hormones, And Oxidative Stress Markers, And Fecal Metabolites And Microbiota Of Obese Cats.

Feline obesity puts many cats at risk for comorbidities such as hepatic lipidosis, diabetes mellitus, urinary tract diseases, and others. Restricted feeding of specially formulated diets may improve feline health and safely support weight loss while maintaining lean mass. The objective of this study was to determine the effects of restricted intake of weight control diets on weight loss, body composition, voluntary physical activity, serum metabolic and inflammatory markers, and fecal metabolites and microbiota of obese cats. Twenty-four obese adult domestic shorthair cats [body weight (BW) = 5.51 ± 0.92kg; body condition score (BCS) = 8.44 ± 0.53] were used. A leading grocery brand diet was fed during a 4-wk baseline to identify intake needed to maintain BW. After baseline (wk 0), cats were allotted to one of two weight control diets (DRY or CAN) and fed to lose 1.5% BW per wk for 18wk. At baseline and 6, 12, 18wk after weight loss, dual-energy x-ray absorptiometry scans were performed, blood and fecal samples were collected, and voluntary physical activity was measured. Change from baseline data were analyzed statistically using the Mixed Models procedure of SAS, with P<0.05 being significant and P<0.10 being trends. BW was reduced by 1.54 ± 0.51% per wk. Restricted feeding of both diets led to BW (P<0.01) and fat mass loss (P<0.01), reduced BCS (P<0.01), reduced leptin (P<0.01) and insulin (P<0.01) concentrations, and increased superoxide dismutase (P<0.01) and active ghrelin (P<0.01) concentrations. Change from baseline fecal scores were reduced (P<0.01) with restricted feeding and weight loss, while total short-chain fatty acid, acetate, and propionate concentration reductions were greater (P<0.05) in cats fed CAN than those fed DRY. Fecal bacterial alpha diversity measures increased (P<0.01) with restricted feeding and weight loss. Fecal bacterial beta diversity was altered by time in all cats, with wk 0 being different (P<0.05) than wk 6, 12, and 18. Change from baseline relative abundances of 3 fecal bacterial phyla and over 30 fecal bacterial genera were impacted (P<0.05) or tended to be impacted (P<0.10) by dietary treatment. Our data demonstrate that restricted feeding of both weight control diets was an effective means for weight loss in obese adult domestic cats. Some changes were also impacted by diet, highlighting the importance of diet formulation and format, and nutrient composition in weight control diets.

291 Isoenergetic reduction of dietary macronutrients changes body composition and physical activity in cats, regardless of body condition, when fed to maintenance

Abstract Commercial extruded cat foods deviate noticeably from the natural diet of wild cats and contain greater carbohydrate and less protein. This alteration in macronutrient distribution is postulated as a potential factor in feline obesity, yet the precise role of carbohydrates in either predisposing to, or treating, obesity in cats remains inconclusive. This study explored the effects of diets differing in protein, fat, and carbohydrates (NFE) on physical activity and body composition when fed to adult male cats to maintain body weight (BW). Three extruded diets were formulated for adult maintenance according to AAFCO in an isoenergetic approach using the same ingredients in varying proportions: low-protein (LP; protein 28% of metabolizable energy [ME], fat 40% ME, NFE 32% ME), low-fat (LF; protein 42% ME, fat 30% ME, NFE 30% ME), or low-carbohydrate (LC; protein 36% ME, fat 41%ME, NFE 23% ME). Lean (n = 9) and obese (n = 9) adult male neutered cats were fed each diet for 4-wk in a 3 x 3 Latin square design. Physical activity was measured via actigraphy on d 15 to 21 of each period. On d 23 total tissue mass (TTM), body fat mass (BFM), lean soft tissue mass (LSTM), and bone mineral content (BMC) were assessed by dual energy x-ray absorptiometry. Daily food intake and weekly BW were recorded. Data were statistically analyzed in SAS Studio via the GLIMMIX procedure with diet and body condition (bc) as fixed effects and cat as subject. A Tukey post-hoc analysis was performed to assess multiple comparisons when significant (P &amp;lt; 0.05). Body weight (Pbc &amp;lt; 0.0001), TTM (Pbc &amp;lt; 0.0001), BFM (Pbc &amp;lt; 0.0001), LSTM (Pbc &amp;lt; 0.0001), and BMC (Pbc = 0.004) were greater in obese compared with lean cats. Regardless of body condition, LSTM was greater in cats consuming the LF diet (P = 0.010). Daily physical activity was similar between lean and obese cats; however, activity as a ratio of light:dark activity was greater for lean cats compared with obese (Pbc = 0.027). Additionally, cats were more active during dark hours when fed LC and LF (Pdiet = 0.016), though no difference was observed for activity during light hours (P = 0.452). These findings support previous observations regarding body composition disparities between lean and obese cats. Contrary to previous reports, no discernible distinctions in voluntary physical activity were noted between lean and obese cats. In previous studies, both high-carbohydrate and high-fat diets reduced voluntary physical activity when fed to maintain BW which was attributed to a potential alteration in mood and energy levels seen in other species. An increase in physical activity in cats consuming the LF diet could suggest a similar pattern. Future research should explore the metabolic implications of varied macronutrient distributions to expand upon the physiological insights presented herein. Funding for this study was provided by Champion Petfoods, Mitacs Accelerate, and the Natural Sciences and Engineering Council of Canada.

308 Isoenergetic reduction of dietary macronutrients reveals distinct fecal metabolomic signatures in lean and obese cats fed at maintenance

Abstract Obesity has become a concerning problem in cats. Increasing evidence demonstrates the utility of metabolomics in identifying disease biomarkers and assessing the effects of nutritional interventions, although limited information exists regarding alterations in fecal metabolites in lean and obese domestic cats in response to different macronutrient content. In the current study, three extruded diets were formulated based on adult maintenance using an isoenergentic approach. These diets were created by adjusting the levels of identical ingredients to achieve a low-protein [LP; protein 28% metabolizable energy (ME), fat 40%ME, NFE 32% ME), a low-fat (LF; protein 42% ME, fat 30% ME, NFE 30% ME), and a low-carbohydrate (LC; protein 36% ME, fat 41% ME, NFE 23% ME] diet. Healthy neutered male adult cats [n = 18; body condition scores (BCS) 4 or 5 (lean, n = 9) and 8 or 9 (obese, n = 9)] were fed each diet for a period of 4 wk in a 3 x 3 Latin square design. Fecal samples from each cat were collected between d 22 and 28 of each treatment period. A total of 67 fecal metabolites in six groups (35 amino acids, 11 fatty acids, 10 sugars and sugar metabolites, 5 alcohols, 3 nitrogenous bases, and 3 others) were analyzed using 1H NMR spectroscopy. To evaluate the impact of body condition, diet and their interaction on each metabolite, proc GLIMMIX covariance structure was selected by the smallest Akaike information criterion value in SAS. The Shapiro-Wilk test was used to check normality and lognormal or beta distribution were applied when appropriate. Bonferroni correction post-hoc test was followed to correct Type I error. Statistical significance was considered at P &amp;lt; 0.05. In lean cats, significantly greater concentrations of fecal proteinogenic and branched-chain amino acids, such as methionine, valine, and L-lysine, as well as pyruvic acid and sugars (P &amp;lt; 0.05) were observed. This suggests that these metabolites may either be more actively fermented by bacteria or not utilized as extensively as in obese cats, potentially contributing to a reduction in obesity status. Regardless of body condition, there is a possibility of an enhanced activity in the tryptophan degradation pathway, leading to the greatest concentrations of fecal tryptophan (P = 0.04) in the LF diet, while the greatest fecal D-galactose (P = 0.04) in the LP diet was likely due to the greater dietary carbohydrate content. These observed results suggested that fecal metabolites were influenced by both body condition and diet; however, body condition had a more substantial impact on metabolite changes in cats, whereas no body condition and diet interaction were noted. Overall, the study indicated distinct fecal metabolic signatures in lean and obese cats subjected to different macronutrient diets and further research is warranted to validate the observed findings. Funding was provided by Champion Petfoods, Natural Sciences and Engineering Council of Canada and Mitacs Accelerate.

Association between Gut Microbiota and Metabolic Health and Obesity Status in Cats.

Obesity is a major public health concern in both humans and animals, leading to several metabolic complications. Recent human studies have classified obesity into two phenotypes, metabolically healthy (MHO) and metabolically unhealthy (MUO) obesity based on cardiovascular and metabolic risk factors. MHO cases lack these risk factors and are protected from metabolic complications of obesity, whereas MUO cases exhibit the opposite characteristics. Moreover, recent studies have highlighted the possible role of the gut microbiome in determining metabolic health of obese individuals. However, studies on the association between the gut microbiome and obesity and metabolic abnormalities in cats are limited. Therefore, we aimed to examine the association between metabolic health phenotypes and gut microbiota composition and diversity in obese cats. We investigated hormone and serum biochemistry parameters and composition of the gut microbiota in non-obese (NO), MHO, and MUO groups. The abundances of Bifidobacteriaceae, Coriobacteriaceae, and Veillonellaceae were significantly higher in the obese versus NO group, showing a positive correlation with body mass index. The abundance of Ruminococcaceae was significantly higher in the MUO versus NO group, showing a positive correlation with triglyceride and total cholesterol levels. However, obesity, whether MHO or MUO, had only a minimal impact on fecal microbiota. Therefore, further studies are warranted to investigate whether gut microbiota could be a beneficial tool for the treatment or management of this condition.

Evidence of obesity-induced inflammatory changes in client-owned cats.

Insulin resistance and type 2 diabetes mellitus are common health issues in obese (OB) cats. In humans, obesity leads to alterations in adipokine and proinflammatory cytokine secretion, causing persistent inflammation. The inflammatory impact of obesity in cats remains unproven. This study investigated associations between obesity and inflammatory and metabolic changes in three groups of client-owned Brazilian domestic shorthair cats: naturally lean, overweight (OW), and OB. Cats from the Veterinary Hospital of Professor Sylvio Barbosa e Cardoso (FAVET/UECE) were clinically evaluated. Blood samples were collected for hematological and biochemical profile measurements, and part of the serum was used for measuring adipokine and inflammatory cytokines using sandwich enzyme-linked immunosorbent assay. In both the OW and OB groups, serum cholesterol and insulin concentrations increased, while triglyceride concentrations were notably elevated in the OB group. In the OW and OB groups, serum adiponectin, tumor necrosis factor-α, and interleukin-1β levels were elevated, and leptin levels were significantly higher in the OB group. This study is the first in Brazil to reveal increased serum levels of inflammatory markers in OW and OB client-owned felines. OW cats exhibited higher proinflammatory marker levels, implying obesity-induced inflammation.

Pet microbiota and its relationship with obesity

The incidence of obesity in pets appears to be increasing in line with the increasing incidence of obesity in humans, and leads to decreased life expectancy. Obesity, which is considered a multifactorial disease caused by excessive adiposity, leads to a decrease in quality of life and serious health problems. It is known that there is an increase in the incidence of respiratory disorders, cardiological disorders, metabolic and endocrine problems, orthopedic diseases and some types of cancer in obese cats and dogs. There are many factors in the formation of obesity. One of these factors is the balance of the microbiota in gut. Many studies have shown that the microbiota affects critical steps in the formation of obesity and there are strong relationships between dietary content, microbiota, and obesity. In particular, high-fat diets are known to increase microbiome composition in terms of gram-negative bacterial strains and trigger dysbiosis. Again, in cases where dysbiosis occurs, the levels of volatile fatty acids also vary and lead to undesirable results through hormonal mechanisms. This condition, which causes hyperphagia, hypertriglyceridemia and insulin resistance, increases the incidence of obesity and diabetes mellitus. The ratio of Firmicutes and Bacteroidetes, which are among the largest phylae of the microbiota, shows serious differences when compared in underweight and obese animals. In this article, these relationships between microbiota and obesity are reviewed.

Gut microbiota promoting propionic acid production accompanies caloric restriction-induced intentional weight loss in cats

Rodent models and human clinical studies have shown gut microbiota-derived short-chain fatty acids (SCFAs) play roles in obesity and insulin resistance. These roles have been minimally explored in cats, where in the USA an estimated 60% of cats are overweight or obese. Overweight/obese research cats (n = 7) were transitioned from a maintenance diet to a reduced calorie diet fed ad libitum for 7 days, then calories were restricted to achieve 1–2% weight loss per week for an additional 77 days. Cats then received their original maintenance diet again for 14 days. Significant intentional weight loss was noted after calorie restriction (adjusted p < 0.0001). 16S rRNA gene amplicon sequencing and targeted SCFA metabolomics were performed on fecal samples. Fecal microbial community structure significantly differed between the four study phases (PERMANOVA p = 0.011). Fecal propionic acid was significantly higher during caloric restriction-induced weight loss (adjusted p < 0.05). Repeated measures correlation revealed the relative abundances of Prevotella 9 copri (correlation coefficient = 0.532, 95% CI (0.275, 0.717), p = 0.0002) significantly correlated with propionic acid composition. Like humans, obese cats experienced an altered microbial community structure and function, favoring propionic acid production, during caloric restriction-induced weight loss.

Body Condition Scores in Cats and Associations with Systolic Blood Pressure, Glucose Homeostasis, and Systemic Inflammation.

Feline obesity is the most common nutritional disease in cats. This study aimed to investigate the differences between systolic blood pressure (SBP) and circulating concentrations of glucose, fructosamine, and serum amyloid-A (SAA) in ideal-weight, overweight, and obese cats. The animals were divided into three groups: ideal-weight (BCS 5, N = 20), overweight (BCS 6, N = 20), and obese cats (BCS ≥ 7, N = 20). SBP, circulating concentrations of glucose, fructosamine, and SAA were evaluated. The SBP values of the ideal-weight, overweight, and obese cats were 140.0 mmHg, 160.0 mmHg, and 160.0 mmHg, respectively. The blood glucose and fructosamine levels for the ideal, overweight, and obese cats were 104.0 mg/dL and 245.0 µmol/L, 123.0 mg/dL and 289.0 µmol/L, and 133.0 mg/dL and 275.0 µmol/L, respectively, for each group. The SAA values were <5 ug/mL in all the groups. The SBP values of the cats with ideal BCS were significantly lower compared to overweight (p = 0.019) and obese (p = 0.001) cats. The blood glucose values of obese cats were higher than those of ideal-weight cats (p = 0.029). There was no statistical difference between the groups for fructosamine and SAA. Obese cats had significantly higher SBP and blood glucose concentrations than ideal-weight cats, showing the effect of BSC on these parameters.

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.

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.

Feline lower urinary tract disease diagnosis in an obese sterile male Persian mixed-breed cat

Feline lower urinary tract disease (FLUTD) occurs because of dysfunction of the urinary bladder and urethra in cats. This study reported that FLUTD occurs in a castrated and obese male cat. The supporting diagnostics used to confirm the diagnosis are the dipstick test, urine microscopic observation, and ultrasound. The examination results showed pyuria, proteinuria, haematuria, struvite crystals, and cystitis. The pathophysiology of FLUTD in this case begins with the condition of castrated males, who tend to have little activity and become obese. Obesity increases the risk of ascending infections, which is one of the causes of crystal formation in the urinary tract.

Investigation of ghrelin and leptin value in obese and non-Obese cats

Obesity is the deterioration of metabolic and physiological functions due to excessive accumulation of fat in the body. The main medical concern of obesity, an increasingly common problem in domestic cats, is that it is associated with many diseases that accompany abnormal fat deposition. Leptin and ghrelin are two hormones involved in energy balance. Ghrelin is an orexigenic hormone while leptin is an anorexigenic hormone. There is still not enough information about these two hormones and there is very little research investigating their connection with obesity. The animal material of this study consists of cats of different breeds, ages and genders, which were brought to clinically healthy routine controls and were healthy according to the results of physical examination, hemogram and blood biochemistry. In this study, 20 cats were evaluated with the body fat measurement system in cats. Those with body fat ratio above 30% were considered obese (n=10), those below 30% were considered as the control group (n=10). Leptin and ghrelin values were measured by ELISA method and their relations with each other were evaluated. Serum leptin (p=0.05) and ghrelin (p=0.001) values were determined in cats in both groups, and statistically significant differences were observed. As a result, it was determined that leptin and ghrelin hormones play an important role in obese cats and are related to each other.

PSVIII-10 An Experimental Weight Management Food Supports Metabolism and Allows for Less Calorie Restriction for Weight Loss in Both Dogs and Cats: a Retrospective Analysis

Abstract Obesity is a growing health concern in dogs and cats. Furthermore, decreased maintenance energy requirements after body weight loss has been linked to rebound weight gain in dogs and cats. Previous research completed by our group has demonstrated that feeding a targeted weight management food to dogs and cats during both the maintenance and weight loss phases results in body weight loss and improved body condition despite increases in caloric intake during the weight maintenance phase. As such, the objective of this study was to investigate the effects of feeding two different weight management foods on weight loss on a per Kcal basis in dogs and cats. Obese adult dogs (n = 39) and cats (n = 38) were subjected to a 36-d maintenance phase and then a 112-d weight loss phase in which they were fed either a standard weight management food (control) or a weight management food that included a blend of specific fibers, immuno-modulators, antioxidant and anti-inflammatory botanicals, and lipotropes (test). During the maintenance phase, pets were fed an adjusted amount of calories needed to maintain weight. Diets were adjusted throughout the weight loss phase to achieve a 1 to 2% reduction in BW per week. Intake was collected daily, and body weight (BW) was recorded every 7 d. To calculate the calorie deficit needed to achieve one unit of weight loss, metabolizable energy estimated from modified Atwater equations and food intake were used and the delta of energy intake between maintenance and body weight loss phases was divided by the delta of the BW change during weight loss. Delta energy/delta weight was reduced (P = 0.020) in cats fed the test food when compared with pets fed the control food such that cats fed the weight loss food required a deficit of 56.5 kcal/d and cats fed the control food required a deficit of 82.8 kcal/d to achieve 1 kg of BW loss. Similarly, delta energy/delta weight was reduced (P = 0.045) in dogs fed the test food when compared with dogs fed the control food such that dogs fed the weight loss food required a deficit of 57.2 kcal/d and dogs fed the control food required a deficit of 95.0 kcal/d to achieve 1 kg of BW loss. Overall, feeding the targeted weight management test food resulted in body weight loss with less of a calorie deficit when compared with feeding the control food, suggesting that the metabolism of dogs and cats is altered by the test food. These data suggest that feeding a food that requires less calorie deficit to lose body weight allows pets to consume more food, contributing to improved satiety, without negating their weight loss process. Future research may support a benefit against rebound weight gain.

190 The Nutrigenomic Effects of Dietary Choline and L-Carnitine on the Muscle and Liver of Lean and Overweight Cats

Abstract The objective of this study was to investigate the effects of dietary choline and L-carnitine on the lipotropic gene expression in the muscle and liver of overweight and lean cats, when fed for body weight (BW)maintenance. Overweight [n = 6, body fat percent (BF%): 33.2 ± 1.38] and lean (n = 6, BF%:18.4 ± 0.93), 1-2 year old, male, neutered cats received choline (378 mg/kg BW0.67), L-carnitine (200 mg/kg BW) and no supplementation (control) in a 3x3 Latin square design for 6 weeks, with a 2-week washout between treatments periods. Each treatment was offered with a commercial extruded diet; diet amount was provided to maintain current BW. Cats were anesthetized and quadriceps vastus lateralis (30-50 mg) and liver (30-50 mg) biopsies were harvested after each treatment period using an open muscle or laparoscopic biopsy technique respectively. Tissue RNA was isolated with TRIzol and sequenced using directional PolyA RNA-seq. The expressed genes were aligned using the reference genome, Felis_catus_9.0, Ensembl v.107. Differential gene expression was analyzed for 29,928 genes with SEQUIN, using edgeR and TMM normalization. Pathway analysis was performed using EnrichR databases, BioPlanet 2019 and KEGG 2021. Using a two-group comparison, global analysis revealed 92 and 759 differentially expressed genes in the liver and muscle, respectively of overweight cats compared with lean (P &amp;lt; 0.05). Affected pathways included fat digestion and absorption, including peroxisome proliferator-activated receptor (PPAR) signaling in the liver, and immunity related pathways in muscle (P &amp;lt; 0.05). Upon further analysis using a two-group comparison between overweight and lean cats for each treatment, 11 and 692 significant genes were found in choline treated liver samples and L-carnitine treated muscle samples, respectively (P &amp;lt; 0.05). Similar to the global analysis, genes related to fat metabolism, including PPAR signaling, were significant in the choline treated liver samples, and immunity related genes were significant in the L-carnitine treated muscle samples (P &amp;lt; 0.05). Based on preliminary data, supplemental dietary choline may be beneficial for overweight cats as it may increase fat metabolism in the liver, mitigating risks associated with feline hepatic lipidosis (FHL). Supplemental dietary L-carnitine may also be beneficial due to its effects on immunity related pathways, including pathogen defense. To investigate the full effects of choline and L-carnitine on gene expression, further studies are warranted including older, chronically obese cats, as well as confirmed cases of FHL. Acknowledgements: Natural Sciences and Engineering Council of Canada, Elmira Pet Products and Balchem Corp.

Dietary choline, but not L-carnitine, increases circulating lipid and lipoprotein concentrations, without affecting body composition, energy expenditure or respiratory quotient in lean and obese male cats during weight maintenance.

Due to the involvement in one-carbon metabolism and lipid mobilization, choline and L-carnitine supplementation have been recommended to minimize hepatic lipid accumulation and support fat oxidation, respectively. This study investigated the lipotropic benefits of choline or L-carnitine supplementation in lean and obese cats maintaining body weight (BW). Lean [n = 9; body condition score (BCS): 4-5/9] and obese (n = 9; BCS: 8-9/9) adult male neutered colony cats were used in a replicated 3 x 3 complete Latin square design. Treatments included choline (378 mg/kg BW0.67), L-carnitine (200 mg/kg BW) and control (no supplement). Treatments were supplemented to the food for 6 weeks each, with a 2-week washout between treatments. Cats were fed once daily to maintenance energy requirements, and BW and BCS were assessed weekly. Fasted blood collection, indirect calorimetry, and dual-energy X-ray absorptiometry occurred at the end of each treatment period. Serum was analyzed for cholesterol (CHOL), high-density lipoprotein CHOL (HDL-C), triglycerides (TAG), non-esterified fatty acids (NEFA), glucose, creatinine (CREAT), urea, alkaline phosphatase (ALP) and alanine aminotransferase (ALT). Very low-density lipoprotein CHOL (VLDL) and low-density lipoprotein CHOL (LDL-C) were calculated. Data were analyzed using proc GLIMMIX, with group and period as random effects, and treatment, body condition, and their interaction as fixed effects, followed by a Tukey's post-hoc test when significance occurred. Cats supplemented choline had lower food intake (P = 0.025). Treatment did not change BW, BCS and body composition (P > 0.05). Obese cats had greater ALP, TAG, and VLDL, and lower HDL-C compared to lean cats (P < 0.05). Choline resulted in greater CHOL, HDL-C, LDL-C and ALT (P < 0.05). L-carnitine resulted in lower CREAT (P = 0.010). Following the post-hoc test, differences between treatment means were not present for ALP (P = 0.042). No differences were found for glucose, urea or NEFA (P > 0.05). Obese cats had a lower fed respiratory quotient (RQ), regardless of treatment (P = 0.045). Treatment did not affect fed or fasted RQ and energy expenditure (P > 0.05). Choline appeared to increase circulating lipid and lipoprotein concentrations regardless of body condition, likely through enhanced lipid mobilization and hepatic elimination. Neither dietary choline or L-carnitine altered body composition or energy metabolism in the lean or obese cats, as compared to control.

Ultrasonography in the diagnosis of obesity in cats and its correlation with fructosamine and lipid levels

The aim of this study was to determine whether ultrasound imaging is an efficient method to assess subcutaneous fat in cats, the anatomical sites where more significant fat deposition occurs, and if there is a correlation between subcutaneous fat thickness and serum levels of cholesterol, triglycerides, and fructosamine. A total of 30 healthy adult cats were used and divided into three groups of 10 animals each, based on the estimated body condition score (BCS). The ideal group (IG) included cats with BCS 3; the overweight group (OWG), with BCS 4; and the obese group (OG), with BCS 5. Ultrasonographic measurement of subcutaneous fat was conducted in five anatomical regions: lumbar, abdominal, thoracic, femoral, and pectoral. We observed that obese cats had greater fat deposition in the abdominal and thoracic regions when compared to those with ideal weight, and that cholesterol and triglyceride levels were higher with the increase in subcutaneous fat thickness in the thoracic region. Nonetheless, there were no differences in fat deposition in the OWG compared to cats from the IG and OG. Ultrasonography allows to differentiate obese cats from those with ideal weight through the analysis of subcutaneous fat thickness in the abdominal and thoracic regions, rendering this method efficient and less subjective.

Direct activation of the fibroblast growth factor-21 pathway in overweight and obese cats.

Feline obesity is common, afflicting ~25-40% of domestic cats. Obese cats are predisposed to many metabolic dyscrasias, such as insulin resistance, altered blood lipids, and feline hepatic lipidosis. Fibroblast Growth Factor-21 (FGF21) is an endocrine hormone that mediates the fat-liver axis, and in humans and animals, FGF21 can ameliorate insulin resistance, non-alcoholic fatty liver disease, and obesity. Activation of the FGF21 pathway may have therapeutic benefits for obese cats. In this preliminary cross-sectional study, ad libitum fed, purpose-bred, male-neutered, 6-year-old, obese and overweight cats were administered either 10 mg/kg/day of an FGF21 mimetic (FGF21; n = 4) or saline (control; n = 3) for 14 days. Body weight, food, and water intake were quantified daily during and 2 weeks following treatment. Changes in metabolic and liver parameters, intrahepatic triglyceride content, liver elasticity, and gut microbiota were evaluated. Treatment with FGF21 resulted in significant weight loss (~5.93%) compared to control and a trend toward decreased intrahepatic triglyceride content. Cats treated with FGF21 had decreased serum alkaline phosphatase. No significant changes were noted in liver elasticity, serum, liver, or metabolic parameters, or gut microbiome composition. In obese and overweight cats, activation of the FGF21 pathway can safely induce weight loss with trends to improve liver lipid content. This exploratory study is the first to evaluate the FGF21 pathway in cats. Manipulation of the FGF21 pathway has promising potential as a therapeutic for feline obesity. Further studies are needed to see if FGF21-pathway manipulation can be therapeutic for feline hepatic lipidosis.

Renal resistive index in obese and non‑obese cats.

This study aimed to compare renal function between obese and normal‑weight healthy cats, using intrarenal resistive index (RI), serum symmetric dimethylarginine (SDMA), and serum creatinine, and to identify the variables that might influence intrarenal RI. Thirty crossbred client‑owned cats met the inclusion criteria and were allocated into two groups: Control and Obese. Body weight, body mass index (BMI), body condition score (BCS), SAP, serum SDMA, urea, and creatinine were evaluated. B‑mode and Doppler ultrasound of the kidneys were done. RI evaluation was in the interlobar artery. SDMA and intrarenal RI were compared between groups, also considering the gender of the cats. A correlation analysis between intrarenal RI with the other parameters was performed. SDMA was higher in the Obese group. Intrarenal RI was higher in females than males in the Obese group. Obese females presented higher RI and SDMA than Control females. A positive correlation was observed between RI, age, body weight, and BMI. Six obese cats (40%) showed increased RI. The increase in body weight, BCS, and BMI resulted in a simultaneous increase in RI and SDMA. The RI may assist in monitoring renal function, and may be associated with preclinical kidney changes in obese cats.

Pathomorphological changes in the liver and internal organs in obese cats

Obesity is the accumulation of excessive adipose tissue in the body and is the most common nutritional disorder in pets. Obesity is one of the most prevalent health conditions in companion animals globally. It is associated with premature mortality, metabolic dysfunction, and multiple health conditions across species. Obesity is, therefore, of importance in the field of veterinary medicine. The regulation of adiposity is a homeostatic process vulnerable to disruption by many genetic and environmental factors. Among dogs, cases are found in 22–24 %, and among cats – in 20 % of animals that visited a veterinary clinic. Approximately one-third of cats older than 12 years of age may have a decreased ability to digest fat, whereas one in five may have a compromised ability to digest protein. More than 40 % of dogs between the ages of 5 and 10 years are overweight or obese. Among the risk factors that cause excessive fat deposition is noted: breed, age, sex, sterilization, lifestyle, endocrine diseases, drug treatment and contraception, feeding, social factor, and the number of animals in the household. Obesity, in turn, affects several metabolic processes and is a factor that affects the development of pathological processes: dyslipidemia, hyperlipidemia, insulin resistance, hyperinsulinemia, type 2 diabetes, excessive deposition of fat in the liver and pancreas, coronary heart disease, disease gallbladder, osteoarthritis, urethral sphincter dysfunction, may increase the risk of certain types of cancer. For research, two groups of cats aged 3–7 years were formed, but breed data were not taken into account. Laboratory blood tests confirmed the clinical observations of specialists regarding overweight cats. The pathoanatomical autopsy with subsequent pathohistological studies made it possible to finally confirm the diagnosis of obesity, which was accompanied by fatty dystrophy of internal organs.

Survey of Belgian owners' perspectives on quality of life and difficulties during a weight-loss programme in obese cats.

The aims of this study were to determine owners' perception of their cats' quality of life (QoL), and whether there is a correlation with weight-loss variables, as well as to identify the main difficulties owners encounter during controlled weight loss in their obese cats. The study was carried out as an e-questionnaire survey addressed to owners of cats starting a weight-loss programme. The e-questionnaire was provided at a single time point after the conclusion of the study (24 weeks). Nineteen completed questionnaires were included. Eighteen cats had a lower weight at the end of the weight-loss period, two of which had successfully reached their target weight. Mean weight loss was 13.84% body weight at a rate of 0.53% weight loss/week. Although the perceived QoL was not correlated with weight-loss variables (P >0.05), it increased over time, even in cats that did not reach their target weight, and was statistically correlated with increased activity (r = 0.73; P <0.01), mobility (r = 0.78; P <0.01) and play time (r = 0.61; P <0.01). The main difficulties encountered by owners were not giving (32%) or permitting the cat to eat extra food (26%). The main presumed difficulty for the cat was having its food decreased over time (53%). Most owners considered their cats happy (42%) and quite happy (53%) during the study, and no statistically significant correlations were found between the weight loss, food-seeking behaviour and stress parameters (P >0.05). Although several difficulties were encountered throughout the study, increased QoL and energy levels in their cats were noticed by owners. A positive perspective on weight-loss programmes is important to keep owners motivated and achieve the target weight in their cats. Furthermore, this survey provides insights into the perceived difficulties of weight-loss regimens in cats.