Aging in cats: Common physical and functional changes.

PRACTICAL RELEVANCE: Aged pets comprise a significant proportion of the small animal veterinarian's patient population; in the USA, for example, it was estimated that over 20% of pet cats were 11 years of age or older in 2011. Certain changes associated with aging are neither positive nor negative, but others are less desirable, associated with illness, changes in mobility or the development of unwanted behaviors. These changes can greatly affect the health and wellbeing of the cat and have a tremendous impact on the owner. CLINICAL CHALLENGES: Regular veterinary examinations are essential for evaluating the health of older patients and for providing owners with guidance regarding optimal care. With the exception of overt disease, however, it is difficult to definitively determine if a cat is displaying changes that are appropriate for age or if they reflect an abnormal process or condition. GOALS: This is the first of two review articles in a Special Issue devoted to feline healthy aging. The goals of the project culminating in these publications included developing a working definition for healthy aging in feline patients and identifying clinical methods that can be used to accurately classify healthy aged cats. This first review provides a thorough, systems-based overview of common health-related changes observed in cats as they age. EVIDENCE BASE: There is a paucity of research in feline aging. The authors have drawn on expert opinion and available data in both the cat and other species.

Evaluating aging in cats: How to determine what is healthy and what is disease.

PRACTICAL RELEVANCE: Many of the changes that occur with aging are not considered pathologic and do not negatively affect overall wellness or quality of life. Ruling out disease is essential, however, when attempting to determine whether an aged cat can be considered 'healthy'. A clear understanding of the normal and abnormal changes that are associated with aging in cats can help practitioners make decisions regarding medical management, feeding interventions and additional testing procedures for their aged patients. CLINICAL CHALLENGES: It can be difficult to determine if a cat is displaying changes that are appropriate for age. For example, healthy aged cats may have hematologic or serum biochemistry changes that differ from those of the general feline population. Assessment of behavioral health and cognitive changes, as well as auditory, olfactory and visual changes, can also be challenging in the aged patient. GOALS: This is the second of two review articles in a Special Issue devoted to feline healthy aging. The goals of the project culminating in these publications included developing a working definition for healthy aging in feline patients and identifying clinical methods that can be used to accurately classify healthy aged cats. This second review proposes criteria for assessing 'healthy aged cats'. EVIDENCE BASE: There is a paucity of research in feline aging. The authors draw on expert opinion and available data in both the cat and other species.

Mannoheptulose has differential effects on fasting and postprandial energy expenditure and respiratory quotient in adult Beagle dogs fed diets of different macronutrient contents.

The present study aimed to determine the effects of mannoheptulose (MH) (8 mg/kg) on energy expenditure (EE), respiratory quotient (RQ) and glycaemic response in healthy adult Beagle dogs (n 8; 9·62 (sem 0·31) kg; body condition score 4·5). The study was designed as replicated 4 × 4 Latin squares with a 2 × 2 factorial treatment structure. The dietary treatments were low carbohydrate (CHO) relative to fat diet (LC; 31 % CHO, 28 % fat) with placebo (0 mg/kg) or MH supplement and high CHO relative to fat diet (HC; 54 % CHO, 11 % fat) with placebo (0 mg/kg) or MH supplement. Dogs were fed to maintain body weight (HC and HC(+MH) 3625 (sem 295) kJ and LC and LC(+MH) 3542 (sem 284) kJ). Resting and postprandial (0-4 h; 5-10 h; 11-17 h; 18-23 h) EE and RQ were determined by indirect calorimetry (days 12 or 14). Glycaemic response to a meal (24 h) and plasma MH concentrations were determined on days 12 or 14. Plasma MH followed first-order kinetics, confirming that MH is absorbed and available to the animal. In the presence of high dietary CHO, MH increased postprandial EE (5-10 h only), suggesting MH increased dietary induced thermogenesis. In contrast to earlier reports, MH did not affect serum glucose or insulin in the present study. Irrespective of MH, dogs adapted RQ to diet composition and dogs consuming the LC diet had a greater incremental AUC for glucose, but not insulin, than dogs consuming the HC diet.

Effects of lactoferrin supplementation on ileal and total tract nutrient digestibility, gastrointestinal microbial populations, and immune characteristics of ileal cannulated, healthy, adult dogs.

Orally supplemented lactoferrin derived from bovine milk is purported to have beneficial effects on gut health of animals. Bovine lactoferrin (0, 60, or 120 mg/d) was fed to ileal cannulated, adult dogs in a replicated 3 x 3 Latin square design with 14 d periods. Control dogs tended (p = 0.06) to have higher fecal DM concentrations compared with dogs supplemented with 120 mg/d lactoferrin (34.5 vs. 32.9%). Fecal scores ranged from 3.0 - 3.3, suggesting that feces of all dogs was near the desired consistency, with dogs supplemented with 120 mg/d lactoferrin tending (p = 0.08) to have higher fecal scores. Ileal azoreductase activity tended (p < 0.10) to be higher in dogs supplemented with 60 or 120 mg/d lactoferrin (609 vs. 592 nmol/h per g ileal DM, respectively) as compared with unsupplemented dogs (272 nmol/h per g ileal DM). The following bacterial groups were measured: bifidobacteria, Campylobacter spp., Clostridium spp., eubacteria, Escherichia coli, Lactobacillus spp., Staphylococcus spp., and Streptococcus spp. Fecal streptococci concentrations were lower (p < 0.05) for dogs receiving 60 mg/d lactoferrin (8.60 log10 cfu/g fecal DM) as compared with unsupplemented dogs (9.19 log10 cfu/g fecal DM) or dogs receiving 120mg lactoferrin/d (9.43 log10 cfu/g fecal DM). Dogs supplemented with 120mg/d lactoferrin tended (p = 0.08) to have higher fecal indole concentrations as compared to unsupplemented dogs (1.80 vs. 1.46 micromol/g fecal DM). Because most bacterial groups measured were unaffected, it appears that lactoferrin did not exhibit prebiotic activity, and based on the data collected, lactoferrin also did not appear to have major effects on indices of health in the dog.

Pullulans and gamma-cyclodextrin affect apparent digestibility and metabolism in healthy adult ileal cannulated dogs.

Pullulan and gamma-cyclodextrin are incompletely digestible, glucose-based, nonstructural carbohydrates synthesized by microorganisms. To determine their effect when incorporated into a complete liquid diet on ileal and total tract nutrient digestibility, ileal cannulated dogs (n = 8) were used in a repeated 4 x 4 Latin-square design. Twice daily, diets were offered containing 30% (DMB) maltodextrin, high-molecular-weight (MW) pullulan (MW 100,000), low-MW pullulan (MW 6300), or gamma-cyclodextrin. Fecal and ileal samples were collected for the last 4 d of each 10-d period. Dogs consuming high-MW pullulan had lower (P < 0.05) dry matter, organic matter, crude protein, fat, carbohydrate ileal and total tract digestibilities, and fecal DM, and higher (P < 0.05) fecal output and fecal scores (indicating looser stools). To evaluate glycemic and insulinemic responses to pullulans, food-deprived dogs consumed 25 g maltodextrin, high-MW pullulan, or low-MW pullulan in a repeated 3 x 3 Latin-square design. Glucose and insulin responses were determined for 180 min. Consumption of 25 g alpha-, beta-, and gamma-cyclodextrin resulted in regurgitation within 60 min. High-MW pullulan reduced (P < 0.05) blood glucose concentration at 15, 30, 45, and 60 min. Compared with maltodextrin, low-MW pullulan and gamma-cyclodextrin did not alter nutrient digestibilities or fecal characteristics to any extent, and low MW pullulan did not affect glycemic response. Although high MW pullulan decreased glycemic response, consumption of large amounts negatively affected nutrient digestibility and fecal characteristics.

Effects of stage of maturity and cooking on the chemical composition of select mushroom varieties.

Select mushrooms were analyzed for proximate constituents and carbohydrate profiles either raw or cooked and at different stages of maturity. White button mushrooms (Agaricus biporus) contained high concentrations of ash (12.5 and 11.9% for immature and mature mushrooms, respectively). Starch and total dietary fiber (TDF) concentrations were higher in maitake (Grifola frondosa) and shiitake (Lentinus edodes) mushrooms. Crude protein (CP) and acid-hydrolyzed fat (AHF) were highest in crimini (Agaricus bisporus) and white button and maitake mushrooms, respectively. Chitin concentrations were highest in portabella (Agaricus bisporus) and enoki (Flammulina velutipes) mushrooms (8.0 and 7.7%, respectively). Oligosaccharides were found in low concentrations in some mushrooms. CP and TDF accounted for 86.4 and 49.3% of mushroom organic matter. Cooking increased starch, TDF, and AHF but decreased CP and chitin concentrations. The chitin concentration increased with mushroom maturity. These results detail the complete carbohydrate profile of several important mushroom varieties.

Extrusion conditions affect chemical composition and in vitro digestion of select food ingredients.

An experiment was conducted to determine the effects of extrusion conditions on chemical composition and in vitro hydrolytic and fermentative digestion of barley grits, cornmeal, oat bran, soybean flour, soybean hulls, and wheat bran. Extrusion conditions altered crude protein, fiber, and starch concentrations of ingredients. Organic matter disappearance (OMD) increased for extruded versus unprocessed samples of barley grits, cornmeal, and soybean flour that had been hydrolytically digested. After 8 h of fermentative digestion, OMD decreased as extrusion conditions intensified for barley grits and cornmeal but increased for oat bran, soybean hulls, and wheat bran. Total short-chain fatty acid production decreased as extrusion conditions intensified for barley grits, soybean hulls, and soybean flour. These data suggest that the effects of extrusion conditions on ingredient composition and digestion are influenced by the unique chemical characteristics of individual substrates.

Gastrointestinal and immunological responses of senior dogs to chicory and mannan-oligosaccharides.

Thirty-four senior dogs (pointers 8-11 years, beagles 9-11 years) were used to evaluate the effects of oligosaccharides on nutritional and immunological characteristics. Dogs were randomly allotted to treatments [1% chicory (CH), 1% mannan-oligosaccharide (MOS), 1% chicory + 1% MOS (CM), or no supplementation (control, CON)] in a parallel design with a 4 week baseline period followed by a 4 week treatment period. Dietary supplementation with MOS or CM tended (P = 0.07) to increase food intake due, in part, to an increase in fermentable fibre and a decrease in energy content of the diet. Although wet faecal output increased (P < 0.05) for dogs supplemented with MOS or CM, when corrected for food intake, no differences were noted. The CM treatment increased (P < 0.05) faecal score (1 = hard and dry, 5 = watery liquid), although these scores remained in a desirable range (3 to 3.5). Chicory supplementation increased (P = 0.07) fat digestibility. Chicory or MOS increased (P < or = 0.05) faecal bifidobacteria concentrations 0.4 and 0.5 log10 cfu/g DM, respectively, compared to the CON, while MOS decreased (P < 0.05) faecal E. coli concentrations. Oligosaccharides did not affect white blood cell (WBC) concentrations, but CH and CM tended to increase (P = 0.10) neutrophil concentrations compared to control dogs. Peripheral lymphocyte concentrations were decreased in dogs supplemented with MOS (P = 0.06) and CM (P < 0.05). Chicory and MOS alter faecal microbial populations and certain indices of the immune system of senior dogs.

Chemical and nutritional characteristics of United States soybeans and soybean meals.

Two experiments were conducted to determine U.S. soybean meal (SBM) variation. In experiment 1, SBM from 55 U.S. processors was evaluated. Significant (P < 0.05) but numerically small differences were detected in dry matter (DM) and organic matter (OM) concentrations. Crude protein (CP) concentrations (51.6-54.6%) were higher (P < 0.05) in SBM produced in the southern U.S. Lipid and total dietary fiber concentrations also differed (P < 0.05). The protein dispersibility index was affected (P < 0.05) by the source of SBM. In experiment 2, soybeans and resultant SBMs were obtained from 10 U.S. processing plants. Soybean DM, OM, and CP concentrations differed (P < 0.05). Soybean meal varied (P < 0.05) in CP (48.2-56.2%), acid-hydrolyzed fat (3.3-9.2%), total dietary fiber (17.0-20.7%), and lysine concentrations. Soybean meal carbohydrate composition was also affected by processing conditions. These results indicate a significant variation in chemical and nutritional characteristics of U.S. SBM from different sources.

Nutritional responses to the presence of inulin and oligofructose in the diets of domesticated animals: a review.

Inulin and oligofructose are prebiotic oligosaccharides fermented in the large intestine. This article provides an extensive review of the effects of these oligosaccharides on gastrointestinal characteristics (microflora, pathogen control, epithelial cell proliferation, putrefactive compound production, fecal characteristics, and nutrient digestibility) and systemic metabolism of carbohydrates, nitrogen, lipids, and minerals in dogs, cats, horses, calves, pigs, poultry, and rabbits. In addition, intake of inulin and oligofructose and considerations in their supplementation to animal diets are discussed. Growth performance and meat production in livestock in response to inulin and oligofructose supplementation are addressed. Finally, the possible substitution of antibiotics with fructans in animal diets and directions for future research are presented.

Effects of supplemental fructooligosaccharides plus mannanoligosaccharides on immune function and ileal and fecal microbial populations in adult dogs.

The goal of this study was to examine whether supplemental fructooligosaccharides (FOS) plus mannanoligosaccharides (MOS) influenced immune function and ileal and fecal microbial populations of adult dogs. Eight adult dogs surgically fitted with ileal cannulas were used in a crossover design. Dogs were fed 200 g of a dry, extruded, kibble diet twice daily. At each feeding, dogs were dosed with either 1 g sucrose (placebo) or 2 g FOS plus 1 g MOS orally via gelatin capsule. Fecal, ileal, and blood samples were collected at the end of each 14-d period to measure microbial populations and immune characteristics. Treatment least squares means were compared using the GLM procedure of SAS. Supplementation of FOS plus MOS increased fecal bifidobacteria and fecal and ileal lactobacilli concentrations. Dogs fed FOS plus MOS also tended to have lower blood neutrophils and greater blood lymphocytes vs placebo. Serum, fecal, and ileal immunoglobulin concentrations were unchanged by treatment. Supplementation of FOS plus MOS beneficially altered indices of gut health by improving ileal and fecal microbial ecology. Supplementation of FOS plus MOS also altered immune function by causing a shift in blood immune cells.

Fructooligosaccharides and Lactobacillus acidophilus modify gut microbial populations, total tract nutrient digestibilities and fecal protein catabolite concentrations in healthy adult dogs.

The objective of this research was to determine whether fructooligosaccharides (FOS) and (or) Lactobacillus acidophilus (LAC) affected concentrations of gut microbial populations, fermentative end products and nutrient digestibilities in healthy adult dogs. Two experiments were performed using 40 adult dogs (20 dogs/experiment). Dogs in each experiment were randomly assigned to one of 4 treatments. Twice daily, treatments were given orally via gelatin capsules: 1) 2 g sucrose + 80 mg cellulose; 2) 2 g FOS + 80 mg cellulose; 3) 2 g sucrose + 1 x 10(9) colony forming units (cfu) LAC; or 4) 2 g FOS + 1 x 10(9) cfu LAC. Data were analyzed by the General Linear Models procedure of SAS. In Experiment 1, FOS resulted in lower (P = 0.08) Clostridium perfringens and greater fecal butyrate (P = 0.06) and lactate (P < 0.05) concentrations. In Experiment 2, FOS supplementation increased (P < 0.05) bifidobacteria, increased lactobacilli (P = 0.08), increased fecal lactate (P = 0.06) and butyrate (P < 0.05), and decreased (P < 0.05) fecal ammonia, isobutyrate, isovalerate and total branched-chain fatty acid concentrations. Dogs fed LAC had the highest fecal concentrations of hydrogen sulfide and methanethiol in Experiment 1 and dimethyl sulfide in Experiment 2, whereas dogs fed FOS had the lowest concentrations of these compounds. Overall, FOS appeared to enhance indices of gut health by positively altering gut microbial ecology and fecal protein catabolites, whereas LAC was more effective when fed in combination with FOS rather than fed alone.

Fructooligosaccharides and Lactobacillus acidophilus modify bowel function and protein catabolites excreted by healthy humans.

The objective of this experiment was to determine whether supplementation with fructooligosaccharides (FOS) and (or) Lactobacillus acidophilus (LAC) affected bowel function and fermentative end-product concentrations in feces of healthy humans. Subjects (n = 68) were enrolled in a randomized, double-blind, placebo-controlled, parallel study design. After a 4-wk baseline period, subjects consumed one of the following treatments twice daily for 4 wk: 1) 3 g sucrose + 80 mg cornstarch; 2) 3 g FOS + 80 mg cornstarch; 3) 3 g sucrose + 1 x 10(9) colony-forming units (cfu) LAC; or 4) 3 g FOS + 1 x 10(9) cfu LAC. Subjects completed 7-d bowel function forms and 3-d dietary records before collection of fresh stool samples at wk 4, 6 and 8. Statistical analyses were performed on differences from baseline using the General Linear Models procedure of SAS. Fructooligosaccharides decreased fecal ammonia (P = 0.07) and isovalerate (P = 0.12) concentrations at wk 6. At wk 8, FOS tended (P = 0.11) to increase fecal putrescine concentrations. Lactobacillus decreased fecal organic matter percentage at wk 6 (P < 0.05) and 8 (P = 0.07). At wk 6 and 8, LAC increased (P < 0.05) fecal 2-methylindole, total indole, and total indole and phenol concentrations. At wk 8, LAC decreased fecal agmatine (P = 0.08) and phenylethylamine (P < 0.05) concentrations. In conclusion, FOS and LAC modified several metabolites associated with gut health, with FOS tending to be beneficial (decreased fecal protein catabolites) and LAC being negative (increased fecal protein catabolites).

In vitro fermentation properties of selected fructooligosaccharide-containing vegetables and in vivo colonic microbial populations are affected by the diets of healthy human infants.

Salsify (Tragopogon porrifolius) and gobo (Arctium lappa) are root vegetables that contain high concentrations of naturally occurring fructooligosaccharides (FOS), nondigestible oligosaccharides that have prebiotic effects on the intestinal microflora. The objective of this study was to compare colonic microbial populations and the fermentation characteristics of gobo and salsify in breast-fed vs. formula-fed infants. Fecal inoculum from breast-fed and formula-fed infants consuming either no solid foods, cereal, or fruit and vegetable purees were fermented in vitro with sweet potato puree plus gobo, salsify puree or a control vegetable, carrot. Breast-fed and formula-fed infants had similar fecal bacteria concentrations, with the exception of Clostridium perfringens (P < 0.10). Introduction of solid foods into the diet of infants was associated with increased fecal concentrations of bifidobacteria (P < 0.10) and decreased concentrations of total aerobes (P < 0.01), C. perfringens (P < 0.001) and Escherichia coli (P < 0.10). Inoculum from feces of breast-fed infants resulted in greater acetate production, whereas inoculum from feces of formula-fed infants resulted in greater propionate and butyrate production (P < 0.05). Fermentation of FOS-containing vegetables by infant fecal inoculum did not differ significantly from fermentation of carrots as assessed by total short-chain fatty acid (SCFA) production. The addition of solids to the diet of infants was associated with increased production of acetate and total SCFA (P < 0.05). It appears that both the composition and fermentative activity of the colonic microflora of human infants is affected by breast-feeding and solid food consumption, but not by short-term exposure to low concentrations of FOS-containing substrates.

Supplemental fructooligosaccharides and mannanoligosaccharides influence immune function, ileal and total tract nutrient digestibilities, microbial populations and concentrations of protein catabolites in the large bowel of dogs.

The goal of this study was to examine whether supplemental fructooligosaccharides (FOS) and (or) mannanoligosaccharides (MOS) influenced indices of gut health of dogs. Adult female dogs (n = 4) surgically fitted with ileal cannulas were fed a dry, extruded, kibble diet twice daily. At each feeding, the following treatments were administered: 1) Control (no FOS or MOS); 2) 1 g FOS; 3) 1 g MOS; or 4) 1 g FOS + 1 g MOS. Fecal, ileal and blood samples were collected during the last 4 d of each 14-d period to measure protein catabolite concentrations, microbial populations, immune characteristics and nutrient digestibilities. Treatment means were compared using preplanned orthogonal contrasts. Dogs supplemented with MOS had lower (P = 0.05) fecal total aerobes and tended to have greater (P = 0.13) Lactobacillus populations. Ileal immunoglobulin (Ig) A concentrations were greater (P = 0.05) in dogs supplemented with FOS + MOS vs. control. Lymphocytes (% of total white blood cells) were greater (P < 0.05) in dogs supplemented with MOS. Serum IgA concentrations also tended (P = 0.13) to be greater in dogs supplemented with MOS. Dogs supplemented with FOS and FOS + MOS had lower (P < 0.05) fecal total indole and phenol concentrations. Dogs supplemented with MOS tended to have lower ileal DM (P = 0.149) and OM (P = 0.146) digestibilities vs. control. Results of this study suggest that dietary supplementation of FOS and MOS may have beneficial effects on colonic health and immune status of dogs.

Oral administration of arabinogalactan affects immune status and fecal microbial populations in dogs.

Seven ileally cannulated dogs were randomly assigned to a control or arabinogalactan (AG) treatments in a 7 x 7 Latin square design to evaluate effects of oral AG administration on nutritional and immunological characteristics. Arabinogalactan treatments included a high (1.65 g/d) and low (0.55 g/d) dose of AG100, AG1000 or AG3000 provided via gelatin capsules. Arabinogalactan forms differed in purification procedures. Each period consisted of a 6-d adaptation followed by a 4-d collection. Blood and fresh fecal samples were collected on d 10 of each period. Fecal score increased (P < 0.02) in dogs supplemented with the low dose of AG1000. Ileal and total tract dry matter (DM) and organic matter (OM) digestibilities were not affected by treatment. Dogs supplemented with the high dose of AG1000 tended (P = 0.15) to have a higher concentration of total aerobic fecal bacteria than control dogs. Dogs supplemented with the low dose of AG1000 and the high dose of AG3000 had higher concentrations of fecal lactobacilli (P = 0.04) and tended to have higher concentrations of fecal bifidobacteria (P < or =0.16) compared with control dogs. Dogs fed the low dose of AG3000 tended (P = 0.10) to have a lower concentration of fecal Clostridium perfringens compared with control dogs. Arabinogalactan treatments did not affect (P > 0.05) serum immunoglobulin G, M or A concentrations. Specific forms and doses of AG increased white blood cell, neutropil and eosinophil concentrations. Arabinogalactan is a unique dietary fiber that affects the digestive physiology and immunological characteristics of dogs.