Clinical health markers in dogs fed raw meat-based or commercial extruded kibble diets

The interest and demand for healthy and less processed foods for human consumption have been mirrored in the pet industry, with an explosion of alternative diets available. Several nontraditional feeding methodologies including raw meat-based diets (RMBDs) are believed by many dog owners to be superior to traditional extruded commercial dog foods. Despite the strong opinions, limited data are available comparing objective health measures among healthy dogs fed using different methods of diet preparation. Therefore, we compared health markers in client-owned dogs fed an RMBD to markers in dogs fed a high-quality extruded kibble. We hypothesized that healthy adult dogs fed RMBD would show differences in biochemical and hematological parameters and improved clinical health scores (e.g., dental, external ear canal, and integument scores) compared with dogs fed a kibble diet. A cross-sectional observational study was performed comparing hematology, serum biochemistry, urinalysis management history, and clinical health scores in healthy client-owned dogs reported as fed RMBD (n = 28) or kibble (n = 27) for >1 yr. Dental, external ear canal, and integument health scores were assigned by a single veterinary evaluator blinded to feed group, using a scale where 0 was normal and 3 was most severely affected. Spearman correlation coefficient (r_s) was calculated to assess the strength and direction of the relationship of biochemical outcomes with age and body condition score (BCS), while analysis of variance was used to determine if biochemical analytes differed by breed or gender. Biochemical data were analyzed using multiple linear regression models, adjusting for the covariates gender, breed, age, and BCS. A composite clinical health score, (CCS) = 9 − (dental score + otitis score + integument score), was compared between feeding groups using Mann–Whitney test. Serum alkaline phosphatase activity (P < 0.001) and globulin concentration (P < 0.001) were lower, while lymphocyte count (P < 0.05) was higher in dogs fed RMBD. No differences were found in urinalysis between diet groups. Dogs fed RMBD showed a slight improvement in CCS compared with kibble-fed dogs (CCS: P = 0.03). Owner management significantly differed with a greater likelihood of management interventions including dietary supplements and sporting activities in the RMBD group. Further work is needed to specifically determine the impact of diet processing and nutrient content on canine health.     

Preliminary assessment of the risk of Salmonella infection in dogs fed raw chicken diets

This preliminary study assessed the presence of Salmonella spp. in a bones and raw food (BARF) diet and in the stools of dogs consuming it. Salmonella was isolated from 80% of the BARF diet samples (P < 0.001) and from 30% of the stool samples from dogs fed the diet (P = 0.105). Dogs fed raw chicken may therefore be a source of environmental contamination.     

Evaluation of the risks of shedding Salmonellae and other potential pathogens by therapy dogs fed raw diets in Ontario and Alberta

Dogs that participate in animal-assisted interventions (AAIs), often called 'therapy dogs', commonly interact with humans whose immune systems are not functioning optimally. The advisability of feeding raw meat (including poultry) to these animals remains a highly contentious issue, in spite of increasing evidence that raw meat is frequently contaminated with Salmonella. We set out to determine if consuming raw meat influences the risk of therapy dogs shedding Salmonella and other pathogens. Two hundred healthy therapy dogs from Ontario and Alberta were enrolled. Between May 2005 and November 2006, fecal specimens were collected from each dog every 2 months for 1 year, along with a log of places visited, antimicrobial use within the home, dog health status and diet. Specimens were cultured for Salmonella, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), extended-spectrum cephalosporinase (ESC) Escherichia coli and Clostridium difficile. Forty (20%) of the dogs were reported to have been fed raw meat at some point during the year. The incidence rate of Salmonella shedding in the raw meat-fed dogs was 0.61 cases/dog-year, compared with 0.08 cases/dog-year in dogs that were not fed raw meat (P < 0.001). Controlling for therapy dog group, the repeated measures, and pig ear consumption and diarrhoea in the 2 months prior to specimen submission, dogs that consumed raw meat were significantly more likely to test positive for Salmonellaat least once during the year than dogs that did not eat raw meat [odds ratio (OR) 22.7; 95% confidence interval (CI) 3.1-58.8; P < 0.001]. Specific Salmonella serovars were more common among dogs that consumed raw meat versus those that did not include S. Typhimurium, S. Heidelberg and S. Kentucky. Raw meat consumption was also significantly associated with shedding ESC E. coli (OR 17.2; 95% CI 9.4-32.3). No associations between C. difficile, MRSA or VRE and consumption of raw meat were detected. We recommend that dogs fed raw meat should be excluded from AAI programmes, particularly when the programmes involve interaction with humans at high risk of infection or adverse sequelae attributable to infection. Furthermore, although AAI dogs may not be representative of the general population of dogs, we also recommend that feeding of raw meat to dogs is to be avoided in homes where immunocompromised people live.     

The occurrence and antimicrobial susceptibility of salmonellae isolated from commercially available canine raw food diets in three Canadian cities

The purpose of the present study was to evaluate the prevalence and antimicrobial resistance patterns of Salmonella isolated from commercially available canine raw food diets in Canada. A total of 166 commercial frozen raw food diet samples were purchased from randomly selected local pet stores in three Canadian cities for a period of 8 months. All samples were evaluated for the presence of Salmonella, serotyped and tested for antimicrobial susceptibility. There was an overall Salmonella prevalence of 21%; chicken was an ingredient for 67% of the Salmonella-positive diets. Eighteen different Salmonella serotypes were recovered, and resistance was observed to 12 of the 16 antimicrobials tested, with the majority of Ontario isolates exhibiting resistance to ampicillin and Calgary isolates to tetracycline. This study demonstrates the potential risk of raw food diets, especially for immunocompromised individuals, and stresses the need for implementing regulatory guidelines for the production of these diets in order to help control and ideally eliminate the bacterial risks associated with their use and consumption.     

Nitrite poisoning in cats and dogs fed a commercial pet food

The death of three cats, from two separate households, was linked to toxic concentrations of sodium nitrite used as a preservative in a commercial pet food. Post-mortem examination of the three cats revealed a brownish discoloration of the blood suggestive of methaemoglobinaemia. Analysis of two samples of the pet food fed to the cats revealed a mean concentration of 2850 mg of total nitrite per kg of food (as fed). In a further incident, ataxia and weakness was noticed in two of four dogs after they were fed the same brand of pet food. One dog was successfully treated for methaemoglobinaemia with intravenous methylene blue.     

Nitrite poisoning in cats and dogs fed a commercial pet food

The death of three cats, from two separate households, was linked to toxic concentrations of sodium nitriterused as a preservative, in a commercial pet food. Post-mortem examination of the three cats revealed a brownish discoloration of the blood suggestive of methaemoglobinaemia. Analysis of two samples of the pet food fed to the cats revealed a mean concentration of 2850 mg of total nitrite per kg of food (as fed). In a further incident, ataxia and weakness was noticed in two of four dogs after they were fed the same brand of pet food. One dog was successfully treated for methaemoglobinaemia with intravenous methylene blue.     

Blood vitamin concentrations in privately owned dogs fed non-standardized commercial diets and after intake of diets with specified vitamin concentrations

The objective was to investigate in a survey study the blood vitamin concentrations in healthy dogs fed non-specified commercial complete diets and in an intervention study to determine the effects of defined dietary vitamin intakes on blood vitamin levels and hair and skin condition. Sixty-four privately owned dogs, aged from 1 to 8 years, without history of skin or coat problems were included. All animals were fed commercial complete diets with uncertain vitamin concentrations before enrolment. The animals were assigned, according to weight and gender, to four groups with graded vitamin intakes. The blood vitamin levels and skin and coat quality of the dogs were investigated at days 0 and day 122. Coat and hair condition was not influenced by the experimental diets. The retinol concentrations were reduced at the end of the experiment compared with the baseline levels, retinyl esters were not influenced. 25-Hydroxycholecalciferol decreased in all groups, alpha-tocopherol was constant or tended to decrease. Ascorbic acid, thiamine pyrophosphate and riboflavin concentrations were not affected by treatment, flavin adenine dinucleotide and pyridoxal-5'-phosphate were partially reduced on day 122. Cobalamin, pantothenate and biotin concentrations increased with higher dietary intakes, folate levels in tendency. In conclusion, this study gives a survey of blood vitamin concentrations in healthy dogs and provides a data base for the evaluation of the vitamin status in health and disease.     

Bacteriological evaluation of commercial canine and feline raw diets

Twenty-five commercial raw diets for dogs and cats were evaluated bacteriologically. Coliforms were present in all diets, ranging from 3.5 x 10(3) to 9.4 x 10(6) CFU/g (mean 8.9 x 10(5); standard deviation 1.9 x 10(6)). Escherichia coli was identified in 15/25 (64%) diets; however, E. coli O157 was not detected. Salmonella spp. were detected in 5/25 (20%) diets; 1 each of beef-, lamb-, quail-, chicken-, and ostrich-based diets. Sporeforming bacteria were identified from 4/25 (16%) samples on direct culture and 25/25 (100%) samples using enrichment culture. Clostridium perfringens was identified in 5/25 (20%) samples. A toxigenic strain of C. difficile was isolated from one turkey-based food. Staphylococcus aureus was isolated from 1/25 (4%) diets. Campylobacter spp. were not isolated from any of the diets.     

Vitamin K deficiency in cats fed commercial fish-based diets

Clinical signs of vitamin K deficiency have been observed in cats offered two commercial canned diets high in salmon or tuna. Some of the queens and kittens offered these diets had died while survivors had increased coagulation times. Necropsies revealed hepatic and, or, gastrointestinal haemorrhages. Coagulation times of survivors returned to normal after vitamin K therapy. The purpose of this study was to induce a vitamin K deficiency in kittens and determine the dietary requirement. Kittens were offered vitamin K-deficient purified diets containing antibiotics and, or, substances inherent in canned fish diets that may have contributed to the deficiency. Clinical signs of vitamin K deficiency were not observed, even though one purified diet contained only 4 μg K₁/kg diet compared with 60 μg in the commercial tuna diet. Therefore, a minimum vitamin K requirement could not be determined using purified diets; nevertheless, canned commercial diets formulated primarily with fish should contain more than 60 μg K₁/kg diet.     

Urinary energy losses in dogs fed commercial extruded foods

Energy and nitrogen losses in the urine were recorded in 134 individual balances with adult (1- to 2-year-old) female Beagles that were fed 23 dry extruded dog foods ranging in crude protein (CP) content from 242 to 360 g/kg dry matter. The energy equivalent of urinary nitrogen was estimated as 33.9 kJ/g N. Both energy losses in the urine corrected for the nitrogen balance, and the metabolizable energy (MEn): digestible energy (DE) ratio were found to be closely related to diet CP content (r : 0.851 and 0.820). The MEn content of extruded dog foods can be accurately calculated from the DE content, either by subtracting 4.59 MJ/kg CP or estimating the MEn/DE ratio from the food CP content by the following equation: MEn/DE=0.98 – 3.44 ± 0.517 × CP (kg/MJ DE).     

Owner impressions of three premium diets fed to healthy adult dogs

OBJECTIVE: To determine owner impressions of 3 premium canine diets when factors such as price and retail source were removed; to compare body condition scores (BCSs) assigned by owners versus a veterinarian; and to determine consistency of owner impressions of diets when owners were not informed that they were feeding the same diet during 2 consecutive periods. DESIGN: Randomized controlled trial. ANIMALS: 44 healthy adult dogs. PROCEDURE: During the initial 12 months of the study, dogs were each fed 3 premium diets for 4 months in random order. After feeding each diet for 1 and 4 months, owners completed questionnaires regarding palatability of the diet; the dog's attitude, energy level, fecal consistency, frequency of defecation, hair coat quality, and BCS; and whether they would feed the diet if available commercially. During the last 4 months of the study, owners fed the same diet they had been feeding during the previous 4 months. RESULTS: Scores for most variables did not differ among diets. However, mean BCS assigned by owners was significantly lower than mean BCS assigned by an investigator, with a moderate correlation between scores. When asked at the end of the third and fourth study periods whether they would consider feeding the diet long-term, 12 of the 44 (27%) owners gave inconsistent responses. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that when unaware of retail price and source, owners have similar impressions of 3 premium diets fed to healthy adult dogs, suggesting that factors other than the diets themselves may affect owner impressions. Owners also underestimate their dog's BCS.     

Insoluble fibres,satiety and food intake in cats fed kibble diets

Fibre is generally considered to dilute food energy, alter intestinal transit time and promote satiety; however, in cats, conflicting results have been found. In this study, two insoluble fibres were evaluated in four feline diets: control (no added fibre); diet with 10% sugar cane fibre; diet with 20% sugar cane fibre; and diet with 10% cellulose. The experiment was conducted with 32 cats, eight animals per diet, over 42 days: 1–7 for diet adaptation; 8–14 for total collection of faeces for digestibility; 15–17 for fresh faeces collection for fermentation products measurements; 18–20 for gastrointestinal transit time determination; 21 and 37 to evaluate the pattern of food intake; and 22 and 42 to assess satiety. Means were compared by analysis of variance and orthogonal contrasts, and the pattern of food intake was compared by repeated‐measures analysis of variance (p < 0.05). The cats exhibited increased food intake after fibre addition to the diets (p < 0.05), achieving similar energy consumption. Cellulose and the two levels of sugar cane fibre reduced nutrient availability and energy digestibility, but only sugar cane fibre reduced fat digestibility (p < 0.05). Faecal output and the number of defecations per day increased with fibre inclusion (p < 0.05). Gastrointestinal transit time did not change with sugar cane fibre inclusion, but it was reduced with cellulose addition (p = 0.032). The pattern of food intake did not change, but cats fed fibre‐supplemented diets exhibited greater consumption of a challenge meal, increasing energy intake (p < 0.01) when exposed to a palatable, energy‐dense food.