Raw Meat-based Diet Research Articles

Raw meat-based diet for pets: a neglected source of human exposure to Salmonella and pathogenic Escherichia coli clones carrying mcr, Portugal, September 2019 to January 2020.

BackgroundThe pet industry is expanding worldwide, particularly raw meat-based diets (RMBDs). There are concerns regarding the safety of RMBDs, especially their potential to spread clinically relevant antibiotic-resistant bacteria or zoonotic pathogens.AimWe aimed to investigate whether dog food, including RMBD, commercially available in Portugal can be a source of Salmonella and/or other Enterobacteriaceae strains resistant to last-line antibiotics such as colistin.MethodsFifty-five samples from 25 brands (21 international ones) of various dog food types from 12 suppliers were screened by standard cultural methods between September 2019 and January 2020. Isolates were characterised by phenotypic and genotypic methods, including whole genome sequencing and comparative genomics.ResultsOnly RMBD batches were contaminated, with 10 of 14 containing polyclonal multidrug-resistant (MDR) Escherichia coli and one MDR Salmonella. One turkey-based sample contained MDR Salmonella serotype 1,4,[5],12:i:- ST34/cgST142761 with similarity to human clinical isolates occurring worldwide. This Salmonella exhibited typical antibiotic resistance (bla TEM + strA-strB + sul2 + tet(B)) and metal tolerance profiles (pco + sil + ars) associated with the European epidemic clone. Two samples (turkey/veal) carried globally dispersed MDR E. coli (ST3997-complexST10/cgST95899 and ST297/cgST138377) with colistin resistance (minimum inhibitory concentration: 4 mg/L) and mcr-1 gene on IncX4 plasmids, which were identical to other IncX4 circulating worldwide.ConclusionSome RMBDs from European brands available in Portugal can be a vehicle for clinically relevant MDR Salmonella and pathogenic E. coli clones carrying genes encoding resistance to the last-line antibiotic colistin. Proactive actions within the One Health context, spanning regulatory, pet-food industry and consumer levels, are needed to mitigate these public health risks.

Risk perception and food safety practices among Slovenian pet owners: does raw meat feeding of pets make a difference?

Commercially produced and home-made raw meat-based pet diets are becoming increasingly popular and have been recognised as an emerging public health risk by the European Food Safety Authority. The aim of this study was to investigate risk perceptions and self-reported pet food preparation practices in the home setting among pet owners who feed raw meat-based diet to pets. An online questionnaire was distributed to pet owners through social media groups. Ultimately, 750 respondents were included in the detailed analysis, divided into two subgroups, a “raw group” consisted of pet owners who provided raw meat-based diets for pets (n = 382), while the “conventional group” consisted of pet owners who did not (n = 368). There was no significant difference between the two groups in overall risk perception. Only one third of respondents in both groups were aware of the potentially fatal consequences of food poisoning. Self-reported frequency of hand washing, and surface cleaning, were significantly higher (p = 0.000) in the raw group than the conventional group. Food safety malpractices were noted in the raw feeding group, with 47% reporting to rinsing raw peat meat before preparing it, and 42% thawing frozen raw peat meat at room temperature on the kitchen counter. The results provide information on the prevalence of feeding raw meat to pets among Slovenian pet owners and provides the basis for developing tailored food safety education campaigns to improve risk awareness and provide food safety recommendations for pet owners providing raw meat-based diets for pets in Slovenia.

Fecal microbiota composition, serum metabolomics, and markers of inflammation in dogs fed a raw meat-based diet compared to those on a kibble diet.

Despite the potential health risks associated with feeding raw and non-traditional diets, the use of these diets in dogs is increasing, yet the health outcomes associated with these diets is not well understood. This study investigates the effect of feeding dogs a kibble or raw meat-based diets on fecal microbiota composition, serum metabolomics and inflammatory markers. Clinically healthy dogs with a history of consuming either kibble (KD, n = 27) or raw meat-based diets (RMBD, n = 28) for more than 1 year were enrolled. Dogs were fed a standardized diet of either a single brand of KD or RMBD for 28 days. Serum and fecal samples were collected for analysis of microbiota, metabolomics, and inflammatory markers. Multiple regression analysis was performed for each of the metabolites and inflammatory markers, with feed group, age and BCS included as independent variables. The fecal microbiota composition differed between the KD and RMBD groups. Beta-diversity and some indices of alpha-diversity (i.e., Shannon and Simpson) were different between the two diet groups. Sixty- three serum metabolites differed between KD and RMBD-fed dogs with the majority reflecting the differences in macronutrient composition of the two diets.Fecal IAP, IgG and IgA were significantly higher in RMBD dogs compared to KD dogs, while systemic markers of inflammation, including serum c-reactive protein (CRP), galectin, secretory receptor of advanced glycation end-products (sRAGE), haptoglobin, and serum IgG were similar in dogs fed either diet. Diet composition significantly affected fecal microbiota composition and metabolome. Although it had a potentially beneficial effect on local inflammatory markers, feeding RMBD had no impact on systemic inflammation. The influence of these changes on long term health outcomes provides an area for future study.

Application of Encapsulated and Dry-plated Food Acidulants to Control Salmonella enterica in Raw Meat-based Diets for Dogs

There is an increasing demand for raw meat-based diets (RMBDs) for dogs, but these foods cannot be heat-pasteurized. Thus, the objective of this study was to evaluate the antimicrobial efficacy of encapsulated and dry-plated glucono delta lactone (GDL), citric acid (CA), and lactic acid (LA) when challenged against Salmonella enterica inoculated in a model raw meat-based diet (RMBDs) for dogs. Nutritionally complete, raw diets were formulated with different levels (1.0, 2.0 and 3.0% (w/w)) of both encapsulated and dry-plated GDL, CA, and LA with both the positive (PC) and the negative controls (NC) without acidulants. The diets were formed into patties of ∼100 g and inoculated with 3-cocktail mixtures of Salmonella enterica serovars, excluding the NC to achieve a final concentration of ∼6.0 Log CFU/patty. Microbial analyses were performed on the inoculated diets and survivors of S. enterica enumerated. Both encapsulated and dry-plated CA and LA had higher log reductions compared to GDL (P < 0.05). However, encapsulated CA and LA at 1.0% (w/w) exhibited higher log reductions (P > 0.05) and preserved product quality compared to the dry-plated acidulants at 1.0%. We concluded that 1.0% (w/w) of encapsulated citric or lactic acids could be successfully applied as an antimicrobial intervention in raw diets for dogs.

Characterization of Escherichia coli in Dogs with Pyometra and the Influence of Diet on the Intestinal Colonization of Extraintestinal Pathogenic E. coli (ExPEC).

Despite its high frequency and clinical relevance, the pathogenesis of canine pyometra remains poorly understood. The most accepted hypothesis is that bacteria involved ascend from the intestinal tract, causing the uterine infection. Extraintestinal pathogenic Escherichia coli (ExPEC) is the most frequent pathogen in canine pyometra, accounting for 57–100% of cases. The aim of the present study was to determine the frequency of phylogenetic groups and virulence factors in E. coli strains isolated from the uterine and rectal swabs of bitches with pyometra (n = 72) and from rectal swabs from healthy bitches fed commercial dry feed (n = 53) or a raw meat-based diet (RMBD; n = 38). A total of 512 strains of E. coli were isolated and divided into five categories according to the origin of the sample: 120 isolates from the uterine content of dogs with E. coli pyometra, 102 from the feces of bitches with E. coli pyometra, 75 from the feces of bitches without E. coli pyometra, 130 feces samples from healthy dogs fed commercial feed, and 85 feces samples from healthy dogs fed a raw meat-based diet. E. coli strains belonging to the B2 phylogroup and positive for virulence factor genes associated with adhesion (fimbriae type P [papC]) and production of toxins (α-hemolysin [hlyA] and uropathogenic specific protein [usp]) predominated in the uterine content and rectal swabs of bitches with E. coli pyometra. Interestingly, a lower growth rate of E. coli from the B2 phylogroup was observed in dogs fed a RMBD than in those fed commercial dry feed. The present study suggests that intestinal colonization by certain types of E. coli could be a risk factor for the occurrence of E. coli pyometra in bitches and that diet can influence intestinal colonization by such strains.

Enteric Organisms Detected in Feces of Dogs With Bloody Diarrhea: 45 Cases

Bloody diarrhea is a common condition in dogs, but studies evaluating the enteropathogens involved specifically in adult dogs are scarce. In the present study, stool samples from 45 adult dogs with bloody diarrhea were evaluated for the four enteric organisms mainly reported in these cases: canine parvovirus type 2 (CPV-2), Clostridioides difficile, Clostridium perfringens, and Salmonella spp. In addition, the samples were also tested for coronavirus, rotavirus, Giardia spp., and Escherichia coli pathotypes to provide a better understanding of possible co-occurrence. Vaccination status, diet, and clinical outcome were also obtained when available. CPV-2b was identified in 17 dogs (37.8%), being the most frequent cause of bloody diarrhea, including completely vaccinated adult dogs. Toxigenic C. difficile and C. perfringens netF+ were detected in 6 (13.3%) and 5 (11.1%) dogs, in some cases in a co-occurrence with other enteric organisms. Three fatal cases of salmonellosis were identified in dogs fed a raw meat-based diet, raising the risks associated with this increasing practice.

Septicaemia and thrombocytopenia caused by Salmonella gallinarum in a dog fed a raw meat-based diet

In recent years, it has become increasingly popular for pet owners to feed their dogs and cats raw meat as an alternative to processed, manufactured diets. Owners are often unaware of the potential risks this may pose for their animals and for themselves, despite the published literature. This article reports the case of a 5-month-old female French Bulldog referred for investigation of acute vomiting, diarrhoea and pyrexia. She was diagnosed with septicaemia, associated with Salmonella gallinarum (identified on blood culture), as well as a positive faecal culture for Campylobacter coli and severe thrombocytopenia (presumably secondary to infection). She received supportive treatment and marbofloxacin, going on to make a full recovery. Considering the Salmonella serovar identified (which is host-specific to poultry) and the animal's lifestyle, it is possible the septicaemia originated from her raw meat diet. Salmonella spp. is potentially zoonotic and can cause acute enteritis in humans. This is the first report of septicaemia with positive blood culture for Salmonella gallinarum, with secondary severe thrombocytopenia (presumably immune-mediated), in a dog that was fed a raw meat diet.

A cluster of Shiga Toxin-producing Escherichia coli O157:H7 highlights raw pet food as an emerging potential source of infection in humans.

In August 2017, a cluster of four persons infected with genetically related strains of Shiga toxin-producing Escherichia coli (STEC) O157:H7 was identified. These strains possessed the Shiga toxin (stx) subtype stx2a, a toxin type known to be associated with severe clinical outcome. One person died after developing haemolytic uraemic syndrome. Interviews with cases revealed that three of the cases had been exposed to dogs fed on a raw meat-based diet (RMBD), specifically tripe. In two cases, the tripe had been purchased from the same supplier. Sampling and microbiological screening of raw pet food was undertaken and indicated the presence of STEC in the products. STEC was isolated from one sample of raw tripe but was different from the strain causing illness in humans. Nevertheless, the detection of STEC in the tripe provided evidence that raw pet food was a potential source of human STEC infection during this outbreak. This adds to the evidence of raw pet food as a risk factor for zoonotic transmission of gastrointestinal pathogens, which is widely accepted for Salmonella, Listeria and Campylobacter spp. Feeding RMBD to companion animals has recently increased in popularity due to the belief that they provide health benefits to animals. Although still rare, an increase in STEC cases reporting exposure to RMBDs was detected in 2017. There has also been an increased frequency of raw pet food incidents in 2017, suggesting an increasing trend in potential risk to humans from raw pet food. Recommendations to reduce the risk of infection included improved awareness of risk and promotion of good hygiene practices among the public when handling raw pet food.

Insights into dog owner perspectives on risks, benefits, and nutritional value of raw diets compared to commercial cooked diets.

BackgroundThe practice of feeding a raw meat-based diet (RMBD) to dogs is a topic of increasing interest to owners and veterinary professionals alike. Despite the research around the practice, particularly about the risk of nutritional imbalances and microbial contamination, an increasing number of dog owners are adopting a raw diet for their dogs. This study expands the research into owner motivations for feeding RMBDs and cooked diets and asks them their opinions about risk and nutritional value.MethodsAn anonymized, online, internationally accessible questionnaire was developed to ascertain owner perspectives on the risks, benefits, and nutritional value of commercially prepared and homemade RMBDs as compared with commercially prepared cooked diets (CCDs).ResultsThe questionnaire was completed by 419 dog owners of diverse backgrounds across the world. Of the participants, 25.3% fed RMBDs. Just over 70.0% of all participants had spoken to their veterinarian about their dog’s nutrition. Owners who fed RMBDs ranked their veterinarian’s knowledge lower and their own knowledge of canine nutrition higher than owners who fed CCDs. They rated commercial and homemade RMBDs as highly nutritious 83.5% and 73.6% of the time, respectively, while only 12.5% rated CCDs as highly nutritious. Owners who fed CCDs ranked RMBDs as highly nutritious less often, but also only ranked CCDs as highly nutritious 52.7% of the time. All participants agreed that CCDs were low risk to human health. Owners who fed RMBDs ranked raw diets as highly risky to human or dog health under 20.0% of the time but deemed CCDs risky to animal health over 65.0% of the time. When asked about benefits of raw diets, the most repeated words offered by owners were “health”, “better”, “coat” and “teeth”. The most repeated risks presented were “bacteria”, “nutrition”, “risk” and “Salmonella”. Owners who fed RMBDs tended to use vague terminology like “health” and “better” when asked why they fed a raw diet. Owners who did not feed RMBDs used more specific terminology like “expensive”, “time” and “risk” when asked why they did not feed a raw diet. Overall, the two groups differed in their perceptions around RMBD and CCD feeding, which highlights the need for a better line of communication and education between veterinarians and owners.

Seroprevalence of hepatitis E virus in dogs in Switzerland.

Hepatitis E virus (HEV) is the causative agent of an acute and in most cases self-limiting hepatitis. Of the four major HEV genotypes that infect humans, genotype 3 and 4 are zoonotic and have been identified in humans but predominantly in pigs and wild boar, which are considered the main reservoirs. However, the known host range of zoonotic HEV may be increasing to comprise additional species, including companion animals. Several studies have identified contact with dogs as a risk factor for HEV infection in humans, yet information on the occurrence of HEV in Swiss dogs is lacking. To examine a possible risk of exposure, this study was designed to assess the seroprevalence of HEV in 84 Swiss dogs. Serum and plasma samples collected from four veterinary clinics were screened for HEV-specific antibodies by HEV-antibody ELISA test kit. In addition, information of 22 dogs regarding the country of origin, the type of dog feed and any history of hunting was recorded. Samples from seropositive animals were also screened for the presence of HEV RNA by quantitative real-time RT-PCR (qRT-PCR). Overall, 38% (32 of 84) of the dogs tested seropositive for anti-HEV, indicating exposure to HEV. Among the 22 dogs for which information was available, HEV-specific antibodies were detected in three of five dogs that were born abroad, in one of two dogs that were fed a raw meat-based diet, and in one hunting dog. No viral RNA could be detected in any of the serum and plasma samples; thus, the genotype of the strains remained undetermined. This study provides further evidence for canine exposure and susceptibility to HEV and highlights the need to further assess the risks of HEV transmission to humans with contact to dogs.

Targeted Metabolomics With Ultraperformance Liquid Chromatography-Mass Spectrometry (UPLC-MS) Highlights Metabolic Differences in Healthy and Atopic Staffordshire Bull Terriers Fed Two Different Diets, A Pilot Study.

Background: While anecdotal evidence has long claimed that a raw meat–based diet (RMBD) improves the metabolic health of canines, no rigorous scientific study has clarified this issue. Canine atopic dermatitis (CAD) has also been linked to metabolic health, but its relation to diet remains poorly understood. This study investigates whether dietary choice is linked to metabolic health in healthy and CAD-diagnosed canines via targeted serum and urine metabolomic analysis of polar, non-ionic metabolites, as well as whether the underlying CAD condition modulates the response to nutritional intake.Materials and Methods: Serum metabolites of client-owned Staffordshire bull terriers, divided into CAD-diagnosed (n = 14) and healthy (n = 6) cohorts, were studied. Urine metabolites of a subset of the CAD-diagnosed canines (n = 8) were also studied. The canines were split into two cohorts based on diet. The first cohort were fed a commercially available high-fat, moderate-protein, low-carbohydrate RMBD (n = 11, CAD diagnosed n = 8, healthy n = 3). Those in the second cohort were fed a commercially available moderate-fat, moderate-protein, high-carbohydrate kibble diet (KD) (n = 9: CAD diagnosed n = 6, healthy n = 3). The diet intervention period lasted approximately 4.5 months (median 135 days). Statistical analyses of the serum profiles across all dogs (n = 20) and the urine profiles of the CAD-diagnosed subset (n = 8) were performed.Results and Discussion: The KD cohort was found to have higher concentrations of methionine than the RMBD cohort, both in serum (all dogs, p < 0.0001) and in urine (CAD-only cohort, p < 0.0002), as well as cystathionine and 4-pyridoxic acid. Methionine plays important roles in homocysteine metabolism, and elevated levels have been implicated in various pathologies. The CAD (n = 14) cohort dogs showed starker metabolic changes in response to diet regarding these pathways compared to the healthy (n = 6) cohort. However, there was no significant change in CAD severity as a result of either diet. Likely due to the higher meat content of the RMBD, higher concentrations of several carnitines and creatine were found in the RMBD cohort. Citrulline was found in higher concentrations in the KD cohort. Our findings provide insight into the relationship between diet and the serum and urine metabolite profiles of canines. They also suggest that neither diet significantly affected CAD severity.

The Effect of Atopic Dermatitis and Diet on the Skin Transcriptome in Staffordshire Bull Terriers.

Canine atopic dermatitis (CAD) has a hereditary basis that is modified by interactions with the environment, including diet. Differentially expressed genes in non-lesional skin, determined by RNA sequencing before and after a dietary intervention, were compared between dogs with naturally occurring CAD (n = 4) and healthy dogs (n = 4). The dogs were fed either a common commercial heat-processed high carbohydrate food (kibble diet) (n = 4), or a non-processed high fat food (raw meat-based diet) (n = 4). At the end of the diet intervention, 149 differentially expressed transcripts were found between the atopic and healthy dogs. The main canonical pathways altered by the dysregulation of these genes were angiopoietin signaling, epidermal growth factor signaling, activation of angiogenesis, and alterations in keratinocyte proliferation and lipid metabolism. On the other hand, 33 differently expressed transcripts were found between the two diet groups, of which 8 encode genes that are annotated in the current version of the dog genome: immunoglobulin heavy constant mu (IGHM), immunoglobulin lambda-like polypeptide 5 (IGLL5), B-cell antigen receptor complex-associated protein beta chain (CD79B), polymeric immunoglobulin receptor (PIGR), cystathionine β-synthase (CBS), argininosuccinate synthase 1 (ASS1), secretory leukocyte peptidase inhibitor (SLPI), and mitochondrial ribosome recycling factor (MRRF). All genes were upregulated in the raw diet group. In conclusion the findings of this study suggest alterations in lipid and keratinocyte metabolism as well as angiogenesis in the skin of atopic dogs. Additionally, a possible enhancement of innate immunity and decrease in oxidative stress was seen in raw food fed dogs, which could have an important role in preventing hypersensitivities and disturbed immunity at young age.

RAW MEAT-BASED DIET (BARF) IN DOGS AND CATS NUTRITION

Diet based on raw meat or more popularly called BARF (Biologically Appropriate Raw Food) is defined as pet food diet that is composed of thermally untreated animal products that are either derived from wild or domestic animals and is used as a pet food diet for pets in households. Raw meat-based diet can be divided into two basic categories: commercially available finished products and diet prepared by pet owner (called homemade BARF). Homemade diets are based on recipes that are enabling the owner to self prepare the diet. Nevertheless, the recepies used do not have to be in coordinance with official recommendations that could potentially result in the development of pathologies as a result of nutrient imbalances. The lack of good quality studies has resulted in a general discussion on the subject of the potential risks and benefits that arise from this feeding practice. Studies have determined higher digestibility and excellent palatability of BARF diets. Nevertheless, studies that would prove beneficial effects of BARF diet on health or as a diet of choice for certain pathologies are lacking. The proponents of BARF diets base their recommendation on studies conducted on a small sample over a short period of time, or on popular publications that have not undergone peer review. On the other hand, research based on evaluation of infectious disease risks when feeding a BARF diet, is of the better quantity and quality. Namely, microbiological safety of BARF diets is a crucial segment that manufacturers are obligated to control with the additional control of all other production procedures (cold chain in all phases of production and storage) to minimize the contamination with zoonotic pathogens.

Effect of different starch sources in a raw meat-based diet on fecal microbiome in dogs housed in a shelter.

A dietary intervention study was assessed to determine if different sources of starch in homemade diets could significantly modify fecal microbiome of dogs. Twenty-seven adult dogs were enrolled and fed a diet based on a mixture of rice and pasta with fresh raw meat (CD). After 90 d, 8 dogs continued to receive CD diet, 10 dogs received a diet made of a raw meat and a complementary food with rice as the main source of starch (B1), and 9 dogs were fed a diet with the same raw meat and a complementary food with potato as the main source of starch (B2). Samples of feces were collected from each dog in the mornings at the beginning of the study and after 15 d and analyzed for pH, ammonia N (N–NH3) and total N, short chain fatty acids (SCFA) and lactic acid. Relative abundance of fecal microbiota was assessed by sequencing and annotating the V3–V4 regions of the 16S rRNA. Total starch intake was similar between diets but differed in the in vitro rate digestion and in the resistant starch, which was higher in B2 than in B1 and CD diets. Dogs fed B2 diet showed lower (P < 0.05) N–NH3 and pH but higher (P < 0.05) molar proportion of lactic acid. Linear discriminant analysis of the genera relative abundances indicated a significant (P < 0.01) increase of SMB53 genus at the end of the study in B1 diet and of Megamonas genus in B1 and B2 diets in comparison to CD diet. These results suggest that changes of starch source in a raw meat-based diet have limited effects on fecal microbiome in healthy dogs, but underline a high variability of microbiota among dogs.

Abnormal bone mineralization in a puppy fed an imbalanced raw meat homemade diet diagnosed and monitored using dual-energy X-ray absorptiometry.

A 4-month-old male Old English Sheepdog was presented for evaluation of a raw meat-based homemade diet after a 1-month history of progressive lameness. Marked dietary deficiencies were detected, which included calcium, phosphorus and vitamin D. Hypovitaminosis D and hypocalcaemia were diagnosed by serum analysis. Evidence of severe diffuse osteopenia was noted on survey radiographs. Dual-energy X-ray absorptiometry (DEXA) was used to quantify bone mineral content and density and compare to published reference ranges. The puppy's initial bone mineralization was markedly subnormal, with bone mineral density 66% lower than expected, and bone mineral content 40% lower than expected. Subsequent DEXA scans were performed at intervals during the puppy's recovery to document the rate of bone re-mineralization and guide therapeutic recommendations. Marked improvement was achieved within 4months through exercise control and feeding of a diet appropriately formulated for large breed puppy growth and development. This report reinforces the necessity of thorough dietary history and highlights the potential for malnutrition in pets fed homemade and raw meat-based diets. Use of DEXA has rarely been reported in clinical cases, yet can be a valuable tool for diagnosing and monitoring cases with abnormal bone mineralization. Further studies using DEXA to track bone mineralization in healthy puppies are encouraged to develop a more robust reference range of bone mineralization in growing dogs of varying sizes, weights and ages.

Highly suspected cases of salmonellosis in two cats fed with a commercial raw meat-based diet: health risks to animals and zoonotic implications

BackgroundFeeding raw meat-based diets (RMBD) to companion animals raises public health concerns for both animals and humans. While considerable attention has been paid to bacterial contamination of commercial pet food, few literature studies have investigated foodborne disease in companion animals. Salmonellosis is reported to be infrequent in cats but no known data or studies estimating feline salmonellosis are available or large-scale epidemiological studies assessing Salmonella risk factors.Case presentationTwo highly suspected cases of salmonellosis in two cats fed with a commercial frozen poultry RMBD are presented, for the first time from the same household. The clinical presentation, diagnostics, treatment and follow-up are reported and the zoonotic implications are discussed.ConclusionsThis case highlights the health risks posed to both animals and owners by feeding RMBD to pets, and suggests that these risks should be considered by veterinary practitioners.