Objective—To assess differences among reported maximum crude fiber (CF), measured CF, and measured total dietary fiber (TDF) concentrations, and determine fiber composition in dry and canned nontherapeutic diets formulated for adult maintenance or all life stages of dogs.
Design—Prospective cross-sectional study.
Sample—Dry (n = 20) and canned (20) nontherapeutic canine diets.
Procedures—Reported maximum CF concentrations were obtained from product labels. Concentrations of CF and TDF were measured in samples of the diets for comparison. For each diet, percentages of TDF represented by insoluble dietary fiber (IDF) and soluble dietary fiber (SDF) were determined.
Results—For dry or canned diets, the median reported maximum CF concentration was significantly greater than the median measured value. Measured CF concentration was significantly lower than measured TDF concentration for all diets. Median percentage of TDF (dry-matter basis) in dry and canned diets was 10.3% and 6.5%, respectively (overall range, 3.9% to 25.8%). Fiber composition in dry and canned diets differed; median percentage of TDF provided by IDF (dry-matter basis) was 83.4% in dry diets and 63.6% in canned diets.
Conclusions and Clinical Relevance—Among the evaluated diets, measured CF concentration underrepresented measured TDF concentration. Diets provided a wide range of TDF concentration, and proportions of IDF and SDF were variable. In the absence of information regarding TDF concentration, neither reported maximum nor measured CF concentration appears to be a particularly reliable indicator of fiber concentration and composition of a given canine diet.
Objective—To determine total dietary fiber (TDF) concentration and composition of commercial diets used for management of obesity, diabetes mellitus, and dietary fat-responsive disease in dogs.
Sample—Dry (n = 11) and canned (8) canine therapeutic diets.
Procedures—Insoluble and soluble dietary fiber (IDF and SDF), high-molecular-weight SDF (HMWSDF), and low-molecular-weight SDF (LMWSDF) concentrations were determined. Variables were compared among diets categorized by product guide indication, formulation (dry vs canned), and regulatory criteria for light and low-fat diets.
Results—SDF (HMWSDF and LMWSDF) comprised a median of 30.4% (range, 9.4% to 53.7%) of TDF; LMWSDF contributed a median of 11.5% (range, 2.7% to 33.8%) of TDF. Diets for diabetes management had higher concentrations of IDF and TDF with lower proportions of SDF and LMWSDF contributing to TDF, compared with diets for treatment of fat-responsive disease. Fiber concentrations varied within diet categories and between canned and dry versions of the same diet (same name and manufacturer) for all pairs evaluated. Diets classified as light contained higher TDF and IDF concentrations than did non-light diets. All canned diets were classified as low fat, despite providing up to 38% of calories as fat.
Conclusions and Clinical Relevance—Diets provided a range of TDF concentrations and compositions; veterinarians should request TDF data from manufacturers, if not otherwise available. Consistent responses to dry and canned versions of the same diet cannot necessarily be expected, and diets with the same indications may not perform similarly. Many diets may not provide adequate fat restriction for treatment of dietary fat-responsive disease.
Procedures—Percentage of TDF as insoluble dietary fiber (IDF), high-molecular-weight soluble dietary fiber (HMWSDF), and low-molecular-weight soluble dietary fiber (LMWSDF) was determined.
Results—Median measured TDF concentration was greater than reported maximum crude fiber content in dry and canned diets. Median TDF (dry-matter) concentration in dry and canned diets was 12.2% (range, 8.11% to 27.16%) and 13.8% (range, 4.7% to 27.9%), respectively. Dry and canned diets, and diets with and without a source of oligosaccharides in the ingredient list, were not different in energy density or concentrations of TDF, IDF, HMWSDF, or LMWSDF. Similarly, loaf-type (n = 11) and gravy-type (4) canned diets differed only in LMWSDF concentration. Disparities in TDF concentrations among products existed despite a lack of differences among groups. Limited differences in TDF concentration and dietary fiber composition were detected when diets were compared on the basis of carbohydrate concentration. Diets labeled for management of obesity were higher in TDF concentration and lower in energy density than diets for management of diabetes mellitus.
Conclusions and Clinical Relevance—Diets provided a range of TDF concentrations with variable concentrations of IDF, HMWSDF, and LMWSDF. Crude fiber concentration was not a reliable indicator of TDF concentration or dietary fiber composition. Because carbohydrate content is calculated as a difference, results suggested that use of crude fiber content would cause overestimation of both carbohydrate and energy content of diets.