Hair ingested by licking during cat grooming can eventually coalesce into solid masses in cat gastrointestinal tract. It is believed that dietary fibre might reduce formation of these trichobezoars (hairballs). The effects of two insoluble fibre sources added to kibble diets were evaluated with respect to trichobezoar faecal excretion. Thirty-two cats and four diets were used in a randomised block design: a control diet without additional fibre, 10 % added sugarcane fibre, 20 % added sugarcane fibre or 10 % added cellulose. Animals were fed for 42 d and during three separate periods (days 15–17, 25–27 and 40–42), the cats were housed individually in metabolic cages and their faeces were totally collected. The faeces were evaluated and the trichobezoars were isolated and classified into small (<1 cm), medium (1·1–2 cm) or large (>2·1 cm). Means were evaluated by repeated measures ANOVA and contrasts (P < 0·05). Cats fed sugarcane fibre shown a linear reduction of small and medium trichobezoar excretion (number per cat per day; P = 0·004) as well as a reduction in trichobezoar mass excretion (mg per cat per day; P < 0·01). The control group showed increased faecal excretion of large trichobezoars (P = 0·003), which were not present in the high sugarcane fibre group (P < 0·006). No effect of cellulose was observed for any evaluated trait. Therefore, long fibres (sugarcane fibre) may cause greater peristaltic stimulation, increasing the propulsion of hair through the gut, but further research is needed to validate this mechanism. In conclusion, sugarcane fibre reduced faecal hairball elimination in cats, which may have clinical applications for the prevention of health problems related to trichobezoars.

Increasingly domestic cats live in an overfeeding and underexercising environment where obesity is a major health concern. One strategy to aid healthy body weight maintenance is dietary energy dilution. Published data indicate that increasing dietary moisture content leads to a reduction in energy intake and increased activity. However, a number of different methodologies were employed in these studies and associated changes in physical activity have only been measured once. The aim of the present study was to determine the effect of diets of three different moisture contents offered in excess of energy requirements, on body weight, energy intake and physical activity in adult neutered cats. Sixty-nine adult cats randomised into three groups, received 100 % of their daily individual maintenance energy requirements (IMER) of dry diet or dry diet hydrated to 40 or 80 % total moisture content (tmc). Baseline activity, intake, body weight and body composition were measured. Following this baseline phase, the cats received the same diets at 200 % of daily IMER and the measurements repeated over the next 28 d. When offered the diets at 200 % IMER, cats fed the dry diet significantly increased body weight and percentage of body fat (P < 0·01), while those offered the hydrated diets did not (P > 0·01). The levels of physical activity in cats offered the hydrated 80 % tmc diet were significantly (P < 0·01) higher than those offered the dry or 40 % tmc diet. We suggest that dietary energy dilution by addition of water may be a useful strategy for healthy body weight maintenance in overfed cats.

Extruded cat foods differ greatly in macronutrient distribution compared with wild-type diets (i.e. small mammals, reptiles, birds and insects). Based on the literature, this variability likely impacts faecal microbial populations. A completely randomised design was utilised to test the impacts of two dietary treatments on faecal microbial populations: (1) chicken-based extruded diet (EXT; n 3 cats) and (2) raw 1–3-d-old chicks (CHI; n 5 cats). Cats were adapted to diets for 10 d. Bacterial DNA was isolated from faecal samples and amplicons of the 16S rRNA V4–V6 region were generated and analysed by 454 pyrosequencing. Faeces of cats fed CHI had greater (P < 0·05) proportions of the following bacterial genera: unidentified Lachnospiraceae (15 v. 5 %), Peptococcus (9 v. 3 %) and Pseudobutyrivibrio (4 v. 1 %). Faeces of cats fed EXT had greater (P < 0·05) proportions of Faecalibacterium (1·0 v. 0·2 %) and Succinivibrio (1·2 v. < 0·1 %). Five genera, including Lactobacillus and Bifidobacterium, were present in a majority of samples (two to three out of three) from cats fed EXT, but were not detected in the samples (zero of five) for cats fed CHI. These shifts in faecal bacterial populations compared with feeding a whole-prey diet may impact the functional capacities of the microbiota and its interaction with the host. Further research is warranted to determine the impacts of these shifts on long-term health of domestic cats.

Many dog owners see homemade diets as a way of increasing the bond with their pets, even though they may not have the convenience of commercial diets. Modifications of ingredients, quality and proportion might change the nutritional composition of the diet, generating nutritional imbalances. The present study evaluated how dog owners use and adhere to homemade diets prescribed by veterinary nutritionists over an extended period of time. Forty-six owners of dogs fed a homemade diet for at least 6 months were selected for the present study. Owners were invited to answer questions by first reading all possible answers and then selecting the one that best indicated their opinion. The results were evaluated through descriptive statistics. Thirty-five owners (76·1 %) found that the diets are easy to prepare. Fourteen owners (30·4 %) admitted to modifying the diets, 40 % did not adequately control the amount of provided ingredients, 73·9 % did not use the recommended amounts of soyabean oil and salt, and 34·8 % did not correctly use the vitamin, mineral or amino acid supplements. Twenty-six owners (56·5 %) reported that their dogs refused to eat at least one food item. All of these alterations make the nutritional composition of the diets unpredictable and likely nutritionally imbalanced. Although homemade diets could be a useful tool for the nutritional management of dogs with certain diseases, not all owners are able to appropriately use this type of diet and adhere to it for an extended period of time and this limitation needs to be considered when recommending the use of homemade diets.

Enhancing performance through dietary measures is constantly sought as some supplements have shown modest performance enhancement in rodents and human subjects. To evaluate a proprietary dietary supplement, a study was undertaken to assess the effect of diet and exercise on blood physiological parameters during a tracking American Fox Hound field championship. Ten dogs were assigned to two different groups. Group A received a commercial kibble and Group B received the same diet with the addition of a supplement added to the dietary premix for 4 weeks before the field event. Blood was collected at rest, immediately following days 1 and 2 of the event and 48 h after day 2. Blood chemistry, complete blood cell counts and cortisol concentrations were analysed. Competition performance was also documented for all dogs using a points system for tracking events. Many chemistry parameters and blood cell counts changed significantly due to exercise. Differences between the dietary groups showed that Group B had significantly lower aspartate aminotransferase on days 1 and 2 of exercise and lower creatine kinase on day 2. Based on tracking scores, dogs in Group B out-performed dogs in Group A. This study suggests that endurance hunting dogs develop changes in serum markers of musculoskeletal integrity that might be mitigated by the addition of the supplement, resulting in better performance. Although intriguing, follow-up controlled studies are needed to ensure that the enhanced performance was not biased due to lack of randomisation.

Feline obesity is a prevalent medical disease and the main therapeutic strategy is dietary energy restriction. However, at present there are no data regarding long-term outcome in this species. The purpose of the present study was to investigate if, as in other species, some cats regain weight following successful weight loss, and to identify any influencing factors in a cohort of client-owned cats with naturally occurring obesity. Twenty-six cats were included, all of which had successfully completed a weight management programme. After weight loss, cats were periodically monitored. The median duration of follow-up was 954 d (72–2162 d). Ten cats (39 %) maintained their completion weight (±5 %), four (15 %) lost >5 % additional weight and 12 (46 %) gained >5 % weight. Seven of the rebounding cats (58 %) regained over 50 % of their original weight lost. Older cats were less likely to regain weight than younger cats (P = 0·024); with an approximately linear negative association between the cat's age and the amount of weight regained (Kendall's τ = −0·340, P = 0·016). Furthermore, cats whose energy intake during weight loss was greater were also more likely to regain weight (P = 0·023). When the characteristics of weight regain in cats were compared with those from a similar cohort of dogs, cats that rebounded were more likely to regain >50 % of the weight they had lost. These results suggest that weight regain, after successful weight loss, is common in obese cats, and that young cats (<7 years of age) are most at risk.

Sled dogs are known to develop numerous serum biochemical changes due to endurance exercise. Previous studies have suggested that mild hyponatraemia and hypokalaemia can develop during endurance racing. The aim of the present study was to determine if serum biochemical alterations are similar to previous reports, and if electrolyte alterations are still present with present feeding practices utilised by mushers. Serum chemistries were obtained from 26 Alaskan Huskies belonging to 3 different teams, before and after a 1600 km race. Meals and snacks were analysed via calculation to determine daily macronutrient and electrolyte intake. Numerous biochemical alterations were observed including significant differences in serum total protein, albumin, globulin, aspartate aminotransferase, creatine kinase, TAG, NEFA and urea nitrogen (P < 0·05). Serum electrolyte status revealed a mild, yet significant decrease in serum sodium (P = 0·002); and serum potassium was not significantly different (P = 0·566). Further examination of the sodium intake across the three teams revealed two teams with an average daily intake of approximately 8·5 g/dog/d (700 mg/4184 kJ) and the other team consuming 11·1 g/dog/d (1200 mg/4184 kJ). Regression analysis shows a significant modest positive correlation between serum sodium decrease and sodium intake per metabolic body weight of the dogs, as well as a modest positive correlation between sodium intake and serum potassium implicating the renin–angiotensin aldosterone system as a major factor involved in sodium and potassium homoeostasis. These findings suggest that consumption of approximately 0·9 g/kg0·75 (1·2 g/4184 kJ) of sodium per d may prevent exercise-induced decreases in sodium and potassium.

While methods to evaluate antioxidant capacity in animals exist, one problem with the models is induction of oxidative stress. It is necessary to promote a great enough challenge to induce measurable alterations to oxidative parameters while ensuring the protocol is compatible with animal welfare. The aim of the present study was to evaluate caged transport as a viable short-term stress that would significantly affect oxidative parameters. Twenty adult Beagle dogs, maintained on the same diet for 60 d prior to the transport, were included in the study. To simulate the stress, the dogs were housed in pairs in transport cages (1·0 m × 1·0 m × 1·5 m), placed on a truck coupled to a trailer and transported for a period of 15 min. Blood collection was performed immediately before and again 3 h after the transportation to evaluate oxidative parameters in blood serum, including thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (TAC), sequestration activity of the radical 2,2-diphenyl-1-picryl-hydrazyl (DPPH•), protein carbonylation (PC), total sulfhydryl groups (SH), alpha-tocopherol (αToc) and retinol (Ret). PC, SH and αToc were not significantly changed in the study; however, TBARS, TAC and DPPH increased, whereas Ret decreased after the transport. Although the lack of a control group of dogs not submitted to transport is a limitation to be considered, we conclude that the transport model is effective in inducing an antioxidant response in dogs and relevant blood parameters show sensitivity to this proposed model.

Activity monitors are increasingly being used to quantify the activity of pet dogs. The aim of the present study was to investigate associations between signalment and activity of free-living pet dogs. Healthy pet dogs were recruited to wear an Actical activity monitor on their collars continuously for 2 weeks in their home environment. At least fifteen dogs were enrolled in each of the following weight ranges: <10, 10–20, 21–30, 31–40, >40 kg and their age, sex and reproductive status recorded. Each dog's intensity of activity for each minute of recording was classified using the total counts for that minute and our pre-established cut-points. The percentage of time dogs spent in sedentary, light or moderate/vigorous activity each day was calculated. Median total daily activity counts and median percentages of time dogs spent in activities of differing intensity were used for the analysis. Associations between signalment characteristics and activity parameters were evaluated with the Mann–Whitney test, the Kruskal–Wallis test and Spearman rank correlations. Ninety-eight dogs were enrolled with ≥17 dogs in each weight category. Time that dogs were sedentary correlated positively with age (r 0·50, uncorrected P < 0·001), while the median total daily activity count (r −0·47, uncorrected P < 0·001), time spent in light (r −0·46, uncorrected P < 0·001) and more vigorous activity (r −0·50, uncorrected P < 0·001) were negatively associated with age. No other significant associations between signalment and activity parameters were found. The lack of differences in activity across weight categories may reflect the impact of lifestyle negating any potential behavioural differences across breeds.

Insects have been proposed as a high-quality, efficient and sustainable dietary protein source. The present study evaluated the protein quality of a selection of insect species. Insect substrates were housefly pupae, adult house cricket, yellow mealworm larvae, lesser mealworm larvae, Morio worm larvae, black soldier fly larvae and pupae, six spot roach, death's head cockroach and Argentinean cockroach. Reference substrates were poultry meat meal, fish meal and soyabean meal. Substrates were analysed for DM, N, crude fat, ash and amino acid (AA) contents and for in vitro digestibility of organic matter (OM) and N. The nutrient composition, AA scores as well as in vitro OM and N digestibility varied considerably between insect substrates. For the AA score, the first limiting AA for most substrates was the combined requirement for Met and Cys. The pupae of the housefly and black soldier fly were high in protein and had high AA scores but were less digestible than other insect substrates. The protein content and AA score of house crickets were high and similar to that of fish meal; however, in vitro N digestibility was higher. The cockroaches were relatively high in protein but the indispensable AA contents, AA scores and the in vitro digestibility values were relatively low. In addition to the indices of protein quality, other aspects such as efficiency of conversion of organic side streams, feasibility of mass-production, product safety and pet owner perception are important for future dog and cat food application of insects as alternative protein source.

There has been a recent increase in the feeding of unconventional diets, including whole-prey diets, to domestic pet cats. Our objective was to characterise faecal microbial populations of domestic cats fed whole and ground (6·35 mm grind) raw 1–3-d-old chicks (Rodent Pro). Faecal samples were collected from neutered male domestic cats (mean age = 5·7 years) fed these diet items in a crossover design. Bacterial DNA was isolated from faecal samples and amplicons of the 16S rRNA V4–V6 region were generated and analysed by 454 pyrosequencing. Faecal microbial populations of cats fed whole v. ground chicks did not differ. During the study, three cats presented with symptoms of infection (anorexia or diarrhoea) and tested clinically positive for Salmonella using a standard PCR method. The remaining cats tested negative. Data were analysed post hoc to test for differences in microbial populations due to clinical status. The predominant genera were Clostridium (9–30 %), unidentified Lachnospiraceae (10–28 %), Blautia (4–19 %), Peptococcus (2–19 %) and Fusobacterium (2–14 %). Faeces of cats testing clinically positive for Salmonella had higher (P ≤ 0·05) proportions of the genera Coprococcus (5·6 v. 0·4 %) and Escherichia (subgenera Shigella; 1·1 v. 0·3 %). Salmonella was not detected in faecal samples utilising the pyrosequencing method; however, there was a shift in microbial populations due to clinical status. The clinical symptoms reported herein may be not only due to the Salmonella itself, but also shifts in other gut microbial populations.

A practical approach to determine apparent faecal digestibility using privately owned dogs may be a useful tool in evaluating differences in nutrient digestibility between dogs with various life stages. The aim was to develop a simple method that would suit such studies using the whitening agent titanium oxide (TiO2) as an indigestible marker. Forty privately owned, healthy male and female dogs of various breeds were included. Selection was based on an owner questionnaire. Means with their standard errors age and body weight (BW) of the dogs were 6·2 (0·6) years (range 1·0–13·0 years) and 22·3 (2·5) kg (range 5·0–43·2 kg), respectively. Owners were provided a commercial dry extruded diet supplemented with a commercially available TiO2 containing kibble (final dietary TiO2 content: 0·77 g/kg). Dogs were fed the diet for seven consecutive days at 480 kJ × BW0·75. On day 7, owners were asked to collect all faeces during 24 h and store faeces at −20°C. Faecal samples were analysed for DM, ash, N, crude fat (CF), crude fibre and Ti and gross energy (GE) and organic matter were calculated. Means with their standard errors apparent faecal digestibility of GE, DM, organic matter, N, CF and crude fibre was 83·7 (0·71), 77·4 (0·79), 83·0 (0·61), 77·7 (0·81), 94·3 (0·51) and 30·3 (4·85), respectively. No significant differences were observed in nutrient digestibility due to weight, age, sex or neuter status. The digestibility assay using a practical approach described here may be a promising tool to determine digestibility of dietary nutrients under free-living conditions. Owner compliance, however, is a potentially limiting factor.

The digestive tract of ferrets is anatomically simple, with no caecum, ileocolic valve or external differentiation between the transition of ileum and colon. The species has a short large intestine that provides minor contributions to the digestive process. Aiming to better understand the digestibility efficiency of ferrets, the present study compared the digestibility of extruded diets with different amounts of macronutrients fed to dogs, cats and ferrets. Three formulations for cat maintenance were used (values in % of DM basis): high carbohydrate (HC; nitrogen-free extract (NFE) = 54 %, protein = 31 % and fat = 8 %); moderate carbohydrate (MC; NFE = 37 %, protein = 41 % and fat = 10 %); and low carbohydrate (LC; NFE = 19 %, protein = 46 % and fat = 23 %). Apparent total tract macronutrient digestibility was determined by the method of total collection of faeces. Results were compared by ANOVA, considering the diet and species effects and their interactions. Means were compared by the Tukey's test (P < 0·05). Dogs and cats presented similar food intakes, but ferrets consumed almost two times more food (g/kg body weight). Species × diet interactions were verified for apparent total tract digestibility (ATTD; P < 0·05). Ferrets presented lower DM digestibility than dogs and cats for all three diets (P < 0·05), lower NFE digestibility than dogs for the three diets and lower NFE digestibility than cats for the HC and LC diets (P < 0·05). For crude protein (CP), ferrets presented lower ATTD than dogs and cats (P < 0·05), whereas for fat, dogs and ferrets presented similar ATTD, and higher values than those presented by cats (P < 0·05). Kibble diets had a lower DM, CP and NFE digestibility when fed to ferrets compared with dogs and cats. Fat digestibility was similar between dogs and ferrets and higher than that for cats.

Dogs participating in endurance exercise, including herding, hunting and racing have a greater energy requirement and may be more susceptible to nutrient depletion, electrolyte imbalance and metabolic stress. The objective of the present study was to investigate the acute response to unstructured mixed exercise in American Foxhounds fed a nutrient-fortified endurance diet. Thirty-nine adult Foxhound dogs (median age: 5·0, range: 2–10 years and median body weight (BW): 36·4, range: 24·9–49·5 kg) were allotted to a standard performance diet (Control) or nutrient-fortified endurance diet for adult dogs (Test). Dogs were balanced by sex, age, BW and athletic performance between diets. All male dogs were intact, whereas all the female dogs were spayed. After 80 d on diet, blood samples were collected via jugular puncture at baseline (0 h), and at 3 and 25 h post-exercise (mean: 17·7 (sem 0·92) km run over 2–3 h). Plasma taurine concentration and complete amino acid (AA) profile, serum chemistry and creatine kinase were measured. Serum chemistry profile remained within normal ranges throughout the study. A significant (P < 0·05) diet by time interaction was observed for calcium, alkaline phosphatase and most AA. Plasma taurine and most essential AA were increased (P < 0·05) after exercise and remained greater (P < 0·05) in dogs fed the Test diet, including the branched-chain AA (isoleucine, leucine and valine). Creatine kinase increased (P = 0·01) after 3 h and returned to baseline after 25 h post-exercise, but was not altered by diet. These data indicate that dogs undergoing a moderate bout of exercise did not suffer from electrolyte imbalance, and that a nutrient-fortified diet resulted in greater plasma taurine and essential AA concentrations.

Endurance sled dogs have unique dietary energy requirements. At present, there is disparity in the literature regarding energy expenditure and thus energy requirements of these dogs. We sought to further elucidate energy requirements for endurance sled dogs under field conditions. Three sled dog teams completing the 2011 Yukon Quest volunteered to provide diet history. Nutritional content was evaluated and a mock meal was analysed for each team. Race data were obtained from www.yukonquest.com. Dogs were weighed at the start of the race in Whitehorse Yukon (WH), a mid-way checkpoint in Dawson Yukon (DS) and at the finish in Fairbanks Alaska. Data are average value per dog or per dog per d. Linear regression compared average weight loss to average kcal/dog consumed daily. Diets and feeding regimes were similar for all three teams. The average daily energy intake and nutrient content was similar for all diets. During leg one (WH to DS), team 1 gained weight overall, whereas the other two teams experienced weight loss. Linear regression revealed 37 638 kJ/dog/d (8995 kcal/dog/d) was required for weight maintenance. During leg two (DS to Fairbanks Alaska), average weights decreased for all three teams. The extrapolated kcal requirement was approximately 57 734 kJ/dog/d (13 799 kcal/dog/d). The carbohydrate contents of these diets also suggest that presumed fat intake for endurance sled dogs may be slightly less than previously thought. Finally, these data support the concept that dietary energy requirements vary substantially with additional variables such as load pulled, terrain and ambient temperature.

The Maillard reaction can occur during processing of pet foods. During this reaction, the ε-amino group of lysine reacts with reducing sugars to become unavailable for metabolism. The aim of the present study was to determine the reactive lysine (RL; the remaining available lysine) to total lysine (TL) ratio of commercial pet foods and to evaluate whether RL levels meet minimal lysine requirements (MLR). Sixty-seven extruded, canned and pelleted commercially available dog and cat foods for growth and maintenance were analysed for proximate nutrient composition, TL and RL. RL was expressed on a metabolisable energy basis and compared with the MLR for maintenance and growth. In dog foods, average RL:TL ratios were 0·87 (se 0·02) for extruded, 0·97 (se 0·02) for canned and 0·85 (se 0·01) for pelleted foods, with the lowest ratio of 0·77 in an extruded diet for growing dogs. In extruded and canned cat foods, the average ratio was 0·91 (se 0·02) and 0·90 (se 0·03), respectively, with the lowest ratio being 0·67 in an extruded diet for growing cats. Variation in the RL:TL ratio between and within processing type indicate that ingredients rather than processing might be the key factor influencing RL content in pet foods. Eight dry foods for growing dogs had RL contents between 96 and 138 % of MLR, indicating that RL has to be between 62 and 104 % digestible to meet the MLR. Considering the variability in RL digestibility, these foods could be at risk of not meeting the MLR for growing dogs. Ingredients and pet foods should be characterised with respect to the RL content and digestibility, to avoid limitations in the lysine supply to growing dogs.

Animal by-product meals have large variability in crude protein (CP) content and digestibility. In vivo digestibility procedures are precise but laborious, and in vitro methods could be an alternative to evaluate and classify these ingredients. The present study reports prediction equations to estimate the CP digestibility of meat and bone meal (MBM) and poultry by-product meal (PM) using the protein solubility in pepsin method (PSP). Total tract CP digestibility of eight MBM and eight PM samples was determined in dogs by the substitution method. A basal diet was formulated for dog maintenance, and sixteen diets were produced by mixing 70 % of the basal diet and 30 % of each tested meal. Six dogs per diet were used to determine ingredient digestibility. In addition, PSP of the MBM and PM samples was determined using three pepsin concentrations: 0·02, 0·002 and 0·0002 %. The CP content of MBM and PM ranged from 39 to 46 % and 57 to 69 %, respectively, and their mean CP digestibility by dogs was 76 (2·4) and 85 (2·6) %, respectively. The pepsin concentration with higher Pearson correlation coefficients with the in vivo results were 0·0002 % for MBM (r 0·380; P = 0·008) and 0·02 % for PM (r 0·482; P = 0·005). The relationship between the in vivo and in vitro results was better explained by the following equations: CP digestibility of MBM = 61·7 + 0·2644 × PSP at 0·0002 % (P = 0·008; R2 0·126); and CP digestibility of PM = 54·1 + 0·3833 × PSP at 0·02 % (P = 0·005; R2 0·216). Although significant, the coefficients of determination were low, indicating that the models were weak and need to be used with caution.

The predisposition of cats to gain weight following neutering is well established; however, there is little information about the distribution and range of post-neutering weight gains observed in cats under a controlled environment. This retrospective study investigated 6-month post-castration weight gain and distribution of percentage body weight (BW) change in a cohort of twenty, male domestic shorthair cats relative to a control group of intact cats. Cats were matched in age (2·0–2·6 years), husbandry conditions and consumed ad libitum the same dry maintenance diet for at least 3 months prior to and 6 months following castration. All cats were castrated within 48 h of each other. All cats gained weight after castration. Mean BW was 4·67 (sd 0·70) kg at the start of the study and 5·93 (sd 1·38) kg at the end of the study, with individual weight gain ranging 3–53 % at 6 months post-neutering. The pre-conception BW of the queens of each cat was compared with the pre- and post-neutering BW of their offspring. The pre-conception BW of the queens was significantly correlated with the offspring's initial BW (ρ = 0·65, P = 0·01), final BW (ρ = 0·67, P = 0·01) and percentage BW change (ρ = 0·54, P = 0·04). A wide range of post-castration weight gains was observed among cats of similar backgrounds and housing conditions. Implementation of effective methods to control food consumption pre-conception and post-neutering may be a strategy for preventing obesity and obesity-related disorders in cats.

The benefits of whole grain consumption have been studied in human subjects, but little research exists on their effects in dogs. The objective of the present study was to test the effects of resistant starch (RS) in the diet of healthy adult dogs. Twelve adult Miniature Schnauzer dogs (eight males, four females; mean age: 3·3 (1·6) years; mean body weight: 8·4 (1·2) kg; mean body condition score: D/ideal) were randomly allotted to one of three treatment groups, which consisted of different amounts of RS supplied in a biscuit format. Dogs received either 0, 10 or 20 g biscuits per d (estimated to be 0, 2·5 or 5 g RS per d) that were fed within their daily energetic allowance. A balanced Latin square design was used, with each treatment period lasting 21 d (days 0–17 adaptation; days 18–21 fresh and total faecal collection). All dogs were fed the same diet to maintain body weight throughout the study. Dogs fed 5 g RS per d had lower (P = 0·03) fat digestibility than dogs fed 0 gRS per d, but DM, organic matter and crude protein digestibilities were not affected. Faecal fermentative end-products, including SCFA and branched-chain fatty acids, ammonia, phenols and indoles, and microbial populations were not affected. The minor changes observed in the present study suggest the RS doses provided to the dogs were too low. Further work is required to assess the dose of RS required to affect gut health.