Commercial Pet Food Research Articles

Quantitative analysis and health risk assessment of selected heavy metals in pet food samples using ultrasound assisted hydrogen peroxide extraction followed by ICP-OES analysis

There is a lack of information regarding the presence of heavy metals in feed ingredients for animals. Therefore, this study examines 10 feed samples collected from commercial pet food in South African market. The optimal working parameters for ultrasound assisted hydrogen peroxide extraction (UA-HPE) confirmed by multivariate optimization were sonication temperature at 80 °C for 60 min, sample mass of 0.1 g, and H2O2 concentration of 5 mol/L. The UA-HPE results demonstrated high accuracy of (>95%), reproducibility (≤1.9%), low method of detection limits (0.3498 and 0.49 μg/g), and strong linearity as confirmed by regression analysis. The environmental friendliness of the UA-HPE method was assessed using AGREEPrep metric tool that resulted with a score of 0.74. The concentration levels of Cd, Pb and As, ranged between 0.86 and 11.34, 4.50–11.45, and 2.61–12.5 μg/g, respectively greater than the standardized limits, whilst Cr, and Sn were below the limits of detection in all pet food. The health index calculations (HI > 1) revealed that the cat, dog, and horse feed pose health risk for animal consumption. Consequently, this study demonstrated a green, efficient, and cost-effective method for the analysis of animal feed with high accuracy.

Detection of antibiotic resistant Enterobacterales in commercial raw pet food: a preliminary study.

Raw diets have become popular in companion animal nutrition, but these diets may be contaminated with harmful bacteria because heat processing is not utilized to mitigate pathogens during the production process. We analyzed 24 commercially available frozen raw canine and feline diets for extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E). Samples were incubated in tryptic soy broth augmented with 50 μg/mL ampicillin to enrich for ESBL-E. ESBL-E were isolated using CHROMagar ESBL plates and isolate identification and antibiotic susceptibility testing were confirmed using the VITEK®2 instrument. ESBL-E were isolated from 42% (10/24) of raw diets, with E. coli, Enterobacter cloacae complex and Klebsiella pneumoniae predominating. Most ESBL-E isolates (71%, 32/45) were multidrug-resistant. Direct plating of samples onto tryptic soy agar yielded bacterial counts >6 log10 for 2 samples from two different manufacturers. This preliminary study justifies further investigation into the potential contribution of raw diets to the dissemination of antibiotic resistant bacteria in companion animals and domestic living spaces.

Microbial assessment of commercial pet foods marketed in the United Arab Emirates

Examining the microbiological characteristics of pet food is imperative to safeguard the health and well-being of companion animals, pet owners, and the surrounding environment. Domestic animals, known for carrying harmful microorganisms, pose a significant health risk, especially in close proximity to people and children. Notably, no studies have previously investigated pet food quality in the Gulf Cooperation Council countries, in particular, the United Arab Emirates (UAE). This study examined the microbiological quality of all stock keeping units (SKUs) of pet foods marketed in UAE (n = 118). Parameters assessed include Total Aerobic Microbial Count (TAMC), Enterobacteriaceae, Total Yeast and Mold Count (TYMC), Salmonella, Listeria monocytogenes, and Clostridium species. Among the 118 samples, 33 (28%) exceeded the acceptable TAMC limit of 106 CFU/g, highlighting significant variations based on manufacturers and ingredients. Eight samples (7%) surpassed the maximum Enterobacteriaceae limit of 3 × 102 CFU/g. TYMC levels exhibited variation, with 33 (28%) exceeding the limit of 104 CFU/g. L. monocytogenes was identified in 44 (37%) of the samples, while Salmonella was not detected. Clostridium contamination was observed in 28 (24%) of the samples. Statistical analyses revealed associations between pet food characteristics and microbial quality, underscoring the imperative for international standards to ensure the safety of pet food. These findings carry significant implications for pet owners, regulatory bodies, and the pet food industry, emphasizing the need for ongoing efforts to enhance the overall quality and safety of pet food products.

Technological Benefits Associated with the Use of Spray-Dried Animal Plasma in Fish-Based Chunks for Canned Pet Food.

Spray-dried animal plasma (SDAP) and wheat gluten (WG) are common binders in wet pet food that provide amino acids and energy, as well as texture and cohesiveness due to their gelling strength, water retention and fat emulsion properties. Binder use is a valuable tool especially in recipes based on ingredients with low technological properties such as fish by-products containing spines and scales and soft texture after cooking. Two basal recipes for chunks in gravy were produced to evaluate experimental treatments. One basal recipe used a mixture of salmon and tuna by-products as the only animal protein sources without binders or with a 20 g/kg inclusion of SDAP or WG. The other basal recipe mimicked a more typical commercial recipe containing meat animal ingredients and a 40 g/kg salmon by-product to develop experimental treatments with and 0, 10, 20, 30 or 40 g/kg inclusions of SDAP. Dry matter, protein, and viscosity were evaluated in raw emulsions. After a 1 h retorting at 121 °C, hardness was measured in emulsions and in cooked chunks, juiciness, and Texture Profile Analysis (TPA) were assessed. Results demonstrated the viability of producing quality chunks in gravy containing only fish by-products including 20 g/kg of SDAP, which significantly increased hardness, elasticity, cohesiveness, and juiciness. There was a positive linear correlation of increased SDAP inclusion rate in the commercial recipe for most of the quality parameters evaluated. Based on these results, the inclusion of SDAP in fish recipes can help manufacturers achieve technological quality control targets for commercial wet pet food and may help producers to successfully formulate new recipes for wet pet food products using fish by-products as the sole animal protein source.

PSVIII-18 Standardized Amino Acid Digestibility and Nitrogen-Corrected True Metabolizable Energy of Frozen Raw, Freeze-Dried Raw, Fresh, and Extruded Dog Foods Using Cecectomized and Conventional Rooster Assays

Abstract Processing conditions, particularly temperature and duration of heating, impact the digestibility of pet foods. Various alternative commercial pet food formats are now available, but few have been well tested. Therefore, the objective of this study was to determine the amino acid (AA) digestibility and nitrogen-corrected true metabolizable energy (TMEn) of frozen raw, freeze-dried raw, fresh, and extruded dog foods using the precision-fed cecectomized and conventional rooster assays. The diets tested were Chicken and Barley Recipe [extruded diet; Hill’s Science Diet (EXT)], Chicken and White Rice Recipe [fresh diet; Just Food for Dogs (FRSH], Chicken Formula [raw frozen diet; Primal (FRZN)], Chicken and Sorghum Hybrid Freeze-dried Formula [hybrid freeze-dried raw diet; Primal (HFD)], and Chicken Dinner Patties [raw freeze-dried diet; Stella & Chewy (FD)]. Two precision-fed rooster assays utilizing Single Comb White Leghorn roosters (1.5 to 2.5 yr, 2.5 to 3 kg) were conducted. In the first assay, 20 cecectomized roosters (n = 4/treatment) were used to determine AA digestibility. In the second assay, 20 conventional roosters (n = 4/treatment) were used to determine TMEn. In both assays, roosters were crop intubated with 12 g of test diet and 12 g of corn, and then excreta were collected for 48 h. The reactive lysine:total lysine ratios were 0.94, 0.96, 0.93, 0.93, and 0.95 for the EXT, FRSH, FRZN, HFD, and FD diets, respectively. In general, FD had the greatest AA digestibilities and EXT had the least AA digestibilities. Arginine digestibilities were different (P < 0.05) across all diets and in this pattern: FD > FRZN > FRSH > HFD > EXT. Isoleucine digestibilities were different (P < 0.05) across all diets, but with a slightly different pattern: FD > FRZN > FRSH > EXT > HFD. Lysine digestibility was greater (P < 0.05) in FD and FRZN than EXT, with other diets being intermediate. Methionine digestibility was greater (P < 0.05) in FD than FRSH, with other diets being intermediate. Threonine digestibility was greater (P < 0.05) in FD than EXT, with other diets being intermediate. Valine digestibilities were different (P < 0.05) across all diets and in this pattern: FD > FRZN > EXT > FRSH > HFD. Digestibilities of the other essential AA were not different among diets. TMEn was greater (P < 0.05) in FRZN than FD, FRSH, and EXT, greater (P < 0.05) in HFD than FRSH and EXT, and greater (P < 0.05) in FD than EXT. In conclusion, our results support the notion that diet processing impacts AA digestibility, with freeze-dried raw, frozen raw, and fresh diets consistently having greater digestibility coefficients, as well greater TMEn, than the extruded diet. More research in dogs is necessary to test the effects of these diet formats on palatability, digestibility, stool quality, and other physiologically relevant outcomes.

79 Functional Amino Acids in Dogs and Cats: Implications for Overall Health

Abstract The majority of pets depend exclusively on commercial pet food supplied by their owners, who now more than ever are looking for diets supporting the health and well-being of their companion animals. Due to the diverse roles of amino acids beyond protein synthesis, their use as functional nutrients in canine and feline nutrition has gained attention. Dietary supplementation of tryptophan or tyrosine, as the precursors of serotonin and catecholamines, respectively, may reduce stress, anxiety-related and agonistic behavior in dogs. Surplus dietary arginine may also confer benefits by improving cognitive function in aging dogs likely through the enhancement of nitric oxide synthesis. In adult cats, phenylalanine has been studied for its potential effect on delaying gastric emptying and promoting satiety, which could aid in prevention of feline obesity. On the other hand, diets with greater dietary lysine:calorie may protect lean body mass of senior cats, and thus, may help combat sarcopenia. Studies investigating the functional role of amino acids in dogs and cats, however, are limited and the results are often conflicting. Additionally, data on empirical determination of amino acid requirements in adult dogs and cats are scarce, potentially preventing the dietary delivery of the ideal ratios of amino acids and subsequently the provision of specific amino acids in targeted doses above the requirement to evaluate their potential functional roles. Consequently, although the functional properties of some amino acids in dogs and cats are promising, more research focusing not only on their potential health benefits, but also on the empirical determination of amino acid requirements in dogs and cats is warranted to promote their use as functional nutrients in pet food.

Inactivation of Salmonella, Shiga Toxin-producing E. coli, and Listeria monocytogenes in Raw Diet Pet Foods Using High-Pressure Processing

Pet food formulated with raw meat can pose health risks to pets and humans. High-pressure processing (HPP) was evaluated to achieve a 5-log reduction ofSalmonella,E. coliSTEC, andL. monocytogenesin commercial raw pet foods and maintain a 5-log reduction throughout post-HPP storage.Three formulation types that varied in the amounts of striated meat, organ meat, bone, seeds, and other ingredients (fruits, vegetables, and minor ingredients) designated as A-, S-, and R-formulations were used.Eight raw diet pet foods, consisting of three beef formulations (A-, S- and R-Beef), three chicken formulations (A-, S-, and R-Chicken), and two lamb formulations (A- and S-Lamb), were inoculated with 7 log CFU/g cocktails ofSalmonella,E. coliSTEC orL. monocytogenes, HPP at 586 MPa for 1–4 min, and stored refrigerated (4°C) or frozen (−10 to −18°C) for 21 days with microbiological analyses at various time intervals.A- formulations (20–46% meat, 42–68% organs, 0.9–1.3% seeds, and 10.7–11.1% fruits, vegetables, and minor ingredients) inoculated withSalmonellaand treated at 586 MPa for at least 2 min achieved a 5-log reduction 1 day post-HPP and maintained that inactivation level during frozen storage. A- and S-formulations inoculated withE. coliSTEC and treated at 586 MPa for at least 2 min achieved a 5-log reduction from day 6 of frozen storage.L. monocytogeneswas more HPP resistant thanSalmonellaandE. coliSTEC.S-formulations containing chicken or beef and stored frozen post-HPP had lower inactivation of L. monocytogenes compared to A-formulations containing chicken or beef. S-Lamb had higher frozen storage inactivation (5.95 ± 0.20 log CFU/g) compared to chicken (2.52 ± 0.38 log CFU/g) or beef (2.36 ± 0.48 log CFU/g). HPP coupled with frozen storage time was effective in achieving and maintaining a 5-log reduction ofSalmonellaandE. coliSTEC whileL. monocytogeneswas more resistant and requires further optimization to achieve a 5-log reduction.

Impact of Animal By-Products on Diet Digestibility and Fecal Quality in Beagle Dogs

In animal feeds and pet food, meat industry rendered by-products as a source of high-quality protein are commonly used. Among all rendered protein sources, poultry carcasses and neck meal are frequently used as ingredients in commercial pet foods due to their agreeable fatty acid and amino acid profiles, and they have no impact on the palatability of the diet. Nonetheless, it is unclear how poultry by-product meal affects companion animals regarding diet digestibility and fecal quality. This study either aimed to provide information on poultry by-product meal, including coarsely, finely, or very finely ground varieties, regarding their nutrient digestibility and characteristics of feces in dogs. One type of animal by-product meal was used in the three aforementioned particle sizes. Beagle dogs (n = 6; body weight, 16.6 kg ± 2.03) participated in a crossover experiment design. Each trial consisted of a five day adaptation period to the diet, and five days of fecal samples were collected and measured for individual apparent nutritional digestibility and fecal scores. The animal by-product supplementation in the diet of dogs was well accepted, with an acceptable percentage of apparent nutrient digestibility. Different particle sizes had no significant effect on the organic matter, crude protein, and crude fat digestibility as well as the fecal fatty acid concentrations. In addition, feces remained firm and well-formed and increased fecal dry matter. This indicates that poultry by-products should be taken into account as a potential dietary protein source in dog food.

Standardized amino acid digestibility and nitrogen-corrected true metabolizable energy of frozen raw, freeze-dried raw, fresh, and extruded dog foods using precision-fed cecectomized and conventional rooster assays.

Processing conditions, particularly temperature and duration of heating, impact pet food digestibility. Various commercial pet food formats are now available, but few have been tested thoroughly. The objective of this study was to determine the amino acid (AA) digestibilities and nitrogen-corrected true metabolizable energy (TMEn) values of frozen raw, freeze-dried raw, fresh (mildly cooked), and extruded dog foods using the precision-fed cecectomized and conventional rooster assays. The diets tested were Chicken and Barley Recipe [Hill's Science Diet, extruded diet (EXT)], Chicken and White Rice Recipe [Just Food for Dogs, fresh diet (FRSH)], Chicken Formula [Primal Pet Foods, frozen raw diet (FRZN)], Chicken and Sorghum Hybrid Freeze-dried Formula [Primal Pet Foods, hybrid freeze-dried raw diet (HFD)], and Chicken Dinner Patties [Stella & Chewy's, freeze-dried raw diet (FD)]. Two precision-fed rooster assays utilizing Single Comb White Leghorn roosters were conducted. Cecectomized roosters (n = 4/treatment) and conventional roosters (n = 4/treatment) were used to determine standardized AA digestibilities and TMEn, respectively. All roosters were crop intubated with 12 g of test diet and 12 g of corn, with excreta collected for 48 h. In general, FD had the highest, while EXT had the lowest AA digestibilities; however, all diets performed relatively well and few differences in AA digestibility were detected among the diets. Lysine digestibility was higher (P < 0.05) in FD and FRZN than EXT, with other diets being intermediate. Threonine digestibility was higher (P < 0.05) in FD than EXT, with other diets being intermediate. Digestibilities of the other indispensable AA were not different among diets. The reactive lysine:total lysine ratios were 0.94, 0.96, 0.93, 0.93, and 0.95 for EXT, FRSH, FRZN, HFD, and FD, respectively. TMEn was higher (P < 0.05) in FRZN than FD, FRSH, and EXT, higher (P < 0.05) in HFD than FRSH and EXT, and higher (P < 0.05) in FD than EXT. In conclusion, our results support the notion that AA digestibilities are affected by diet processing, with FD, HFD, FRZN, and FRSH diets having higher AA digestibility coefficients and greater TMEn values, than the EXT diet; however, other factors such as ingredient inclusion and macronutrient composition may also have affected these results. More research in dogs is necessary to test the effects of format on diet palatability, digestibility, stool quality, and other physiologically relevant outcomes.

The role of black soldier fly larval protein and fat in companion-animal nutrition: challenges and opportunities from an industry perspective

The pet-food industry is a significant and rapidly growing market, with global sales estimated at over US$100 billion in 2020. The market size for pet food was estimated at 22.9 million tonnes in 2020. The number of cats and dogs being fed commercial pet food is also on the rise, with an estimated 62% of cats and 68% of dogs being fed commercial pet food in the United States alone with an estimated value of A$2.3 billion in 2020. This represents a growth of 3.3% from the previous year, and the market is expected to continue growing with a forecast compound annual growth rate (CAGR) of 3.4% from 2021 to 2025. The demand for high-quality, specialised pet-food products has led to consistent year-on-year growth in the industry. With this, the increasing demand for commercial pet food on a global scale comes with growing sustainability challenges that must be addressed. In this paper, we will examine some of the opportunities for the use of black soldier fly larvae (BSFL) meal and oil in pet-food formulations to reduce the environmental impact of pet food and pet ownership and deliver nutritional and functional benefits to our pets.

Microbiological safety of commercial canned and dry pet food products in Lebanon.

Estimating the microbiological quality of pet food is essential in providing healthy and safe foods to pets. The aim of this study was to assess the microbiological safety of pet food marketed in Lebanon, namely cat and dog products. To the best of our knowledge, no studies have been conducted in Lebanon nor the Middle East region with reference to pet food quality. Lebanese market was screened and a total of 165 dry and canned pet food products were identified, collected and analyzed for their load of total aerobic microbial count, Enterobacteriaceae species, yeasts and molds, and for the presence of Salmonella and Listeria species. Dry pet food products had higher contamination level compared to canned ones. In terms of non-conformity to the European commission regulations, out of the 165 brands, 11 (7%) had a total aerobic microbial count above 106 cfu/g, and 27 (16%) exceeded 3 × 102 cfu/g as a maximum limit of presumptive Enterobacteriaceae. Among the dry brands, 8 out of 66 (12%) had a contamination level of yeasts and molds above 104 cfu/g. Presumptive Salmonella spp. was detected in 68 (41%) and presumptive Listeria spp. in 106 (64%) of brands. These alarming results necessitates setting and monitoring microbiological standards for pet food in Lebanon. This study contributes as well to the building of a database for knowledge development regarding the potential contamination of pet food by the abovementioned microorganisms.

Nutrient and Maillard reaction product concentrations of commercially available pet foods and treats.

Thermal processing is used to produce most commercial pet foods and treats to improve safety, shelf life, nutritional characteristics, texture, and nutrient digestibility. However, heat treatments can degrade protein quality by damaging essential amino acids, as well as contribute to the Maillard reaction. The Maillard reaction forms melanoidins that favorably improve food qualities (e.g., color, flavor, aroma), but also form Maillard reaction products (MRP) and advanced glycation end-products that may negatively affect health. Because commercial pet diets are frequently fed to domestic cats and dogs throughout their lifetimes, it is critical to quantify MRP concentrations and understand the variables that influence their formation so future diets may be formulated with that in mind. Because few research studies on MRP in pet diets have been conducted, the goals of this study were to measure the MRP in commercial pet foods and treats, estimate pet MRP intake, and correlate MRP with dietary macronutrient concentrations. Fifty-three dry and wet dog foods, dog treats, and cat foods were analyzed for dry matter, organic matter, crude protein, acid-hydrolyzed fat, total dietary fiber, and gross energy using standard techniques. MRP were analyzed using high-performance liquid chromatography and gas chromatography-mass spectrometry. Data were analyzed using the Mixed Models procedure of SAS 9.4. Dry foods had lower reactive lysine concentrations and reactive lysine: total lysine ratios (indicator of damage) than wet foods. Wet foods had more fructoselysine (FRUC) than dry foods; however, dry dog treats contained more FRUC than wet dog treats. The greatest 5-hydroxymethyl-2-furfural (HMF) concentrations were measured in dry and wet dog foods, whereas the lowest HMF concentrations were measured in dry and wet cat foods. Based on dietary concentrations and estimated food intakes, dogs and cats fed wet foods are more likely to consume higher carboxymethyllysine and FRUC concentrations than those fed dry foods. However, dogs fed wet foods are more likely to consume higher HMF concentrations than those fed dry foods. In cats, those fed dry foods would consume higher HMF concentrations than those fed wet foods. We demonstrated that pet foods and treats contain highly variable MRP concentrations and depend on diet/treat type. In general, higher MRP concentrations were measured in wet pet foods and dry treats. While these findings are valuable, in vivo testing is needed to determine if and how MRP consumption affect pet health.

Smart sensory polymer for straightforward Zn(II) detection in pet food samples

We report on an innovative method to measure the Zn(II) concentration in commercial pet food samples, both wet and dry food. It is based on a colorimetric sensory polymer prepared from commercial monomers and 0.5 % of a synthetic monomer having a quinoline sensory core (N-(8-(2-azidoacetamido)quinolin-5-yl)methacrylamide). We obtained the sensory polymer as crosslinked films by thermally initiated bulk radical polymerization of the monomers of 100 μm thickness, which we punched into Ø6 mm sensory discs. The immersion of the discs in water solutions containing Zn(II) turned the fluorescence on, allowing for the titration of this cation using the G parameter of a digital picture taken to the discs. The limits of detection and quantification were 29 and 87 µg/L, respectively. Furthermore, we measured the concentration of Zn(II) even in the presence of other cations, detecting no significant interferences. Thus, in a further step, we obtained the concentration of Zn(II) from 15 commercial pet food samples, ranging from 19 to 198 mg/kg, following a simple extraction procedure and contacting the extractant with our sensory discs. These results were contrasted with that obtained by ICP-MS as a reference method.

Effects of extrusion specific mechanical energy and dryer conditions on the survival of Bacillus coagulans GBI-30, 6086 for commercial pet food applications

In companion animal nutrition, probiotics (direct-fed microbials) are considered functional ingredients that benefit the gastrointestinal and immune health of the host. Bacillus coagulans GBI-30, 6086 is a spore-forming bacterial strain that has been reported to survive environmental stresses, heat processing, and extreme-pH conditions. Extrusion cooking is the most widely used method to produce commercial dog and cat foods, however the thermal and mechanical forces exerted during extrusion and drying present a challenge for guaranteeing the viability of live microorganisms after processing. Two experiments were conducted to determine the reduction in viability of the microorganism at graded flour inoculation levels (0, 6.2, 6.7, and 7.3 log10 colony forming units per gram (CFU/g)) subjected to extrusion cooking under varied levels of specific mechanical energy that were achieved by adjusting the extruder water input (10, 12, and 20 kg/h), and extruder screw speed (400, 500, and 600 rpm). A second experiment was conducted to determine the survival of the microorganism subjected to three dryer conditions (49 °C for 10 min; 107 °C for 16 min; and 66 °C for 46 min). Enumeration of bacterial colony forming units was performed on pre- and post-processing samples. Extrusion data were analyzed using a general linear model using the GLIMMIX procedure, and dryer data were analyzed as a completely randomized design with one-way analysis of variance (SAS v. 9.4, SAS Institute, Inc., Cary, NC) with significance accepted at a level of 95% confidence (α = 0.05). The results indicate that the low SME extrusion conditions (in-barrel moisture of 35%, extruder screw speed of 400 rpm, and specific mechanical energy of 129 kJ/kg) resulted in the greatest retention (P < 0.05), with a mean log10 reduction of viable spores of 0.44, 2.15, and 2.67 for the low, moderate, and severe extrusion conditions, respectively. Viability of the spores through three dryer conditions were observed to be similar across all treatments. This study also demonstrated that the greatest losses of viability occurred during extrusion rather than drying, and that in-barrel moisture and extruder screw speed are two operational parameters may be modified for the optimization of Bacillus coagulans survival in extruded foods.

Elemental composition in commercial dry extruded and moist canned dog foods

The aim of the study was to investigate elemental contents in commercial pet foods for adult dogs at maintenance. The elemental composition of 15 dry extruded diets (DED) and 22 moist canned diets (MCD) collected from a pet shop were analyzed in triplicate with inductively coupled plasma optical emission spectroscopy and with mass spectrometry for Se. Significantly higher contents of Ca, P, (P < 0.05), K and Na (P < 0.0001) were measured in MCD than in DED, whilst the contrary was observed for Cu and Zn (P = 0.001). All the analyzed foods supplied on average micro minerals above the recommended daily requirements of FEDIAF, except for Cu (mean supply of foods 85%+12) in the MCD and Se both in DED (mean supply in foods 21%+4) and MCD (mean supply in foods 34%+7) samples. All the analyzed foods supplied macro elements above the recommended daily allowances except for K (73%+6) in the DED and Mg (92%+5) in MCD. Principal component analysis with essential elements (EE) as input variables (Ca, P, K, Na, Mg, Fe, Mn, Zn, Cu, Se) explained 63.85% of total variance with the first two components and clustered DED and MCD. Factor scores of Cu, Zn, Mg and Mn were higher for MCD and Ca, P, K and Na for DED. Significantly higher (P < 0.01) frequency of presence of non essential elements (NEE) Cd, Cr, Li and Pb (p < 0.01) were observed in MCD in comparison to DED. Although there are limitations in this study, the results showed a wide variability of elemental contents among per foods and suggest the need of routinely analysis to accomplish with the recommended daily allowances and for the safeguard of companion animals health.

Toxic element levels in ingredients and commercial pet foods

Nowadays, there is a growing concern about contamination of toxic metals (TM) in pet food due to the great potential for health risks of these elements. TM concentrations in commercial pet foods (n = 100) as well as in ingredients used in their composition (n = 100) were analyzed and compared to the Food and Drug Administration (FDA) maximum tolerable level (MTL), and the TM concentrations found in the different sources of carbohydrate, protein, and fat were compared. The TM concentrations were determined by inductively coupled plasma with optical emission spectrometry (ICP-OES). Concentrations above the MTL for aluminum, mercury, lead, uranium, and vanadium were observed in both dog and cat foods, and the percentage of dog foods that exceeded the MTL of these TM were: 31.9%; 100%; 80.55%; 95.83%; and 75%, respectively, and in cat foods: 10.71%; 100%; 32.14%; 85.71%; 28.57%, respectively. The MTL values of these TMs and the mean values in dog foods (mg/kg dry matter basis) (MTL [mean ± standard deviation]) were: aluminum: 200 (269.17 ± 393.74); mercury: 0.27 (2.51 ± 1.31); lead: 10 (12.55 ± 4.30); uranium: 10 (76.82 ± 28.09); vanadium: 1 (1.35 ± 0.69), while in cat foods were: aluminum: 200 (135.51 ± 143.95); mercury: 0.27 (3.47 ± 4.31); lead: 10 (9.13 ± 5.42); uranium: 10 (49.83 ± 29.18); vanadium: 1 (0.81 ± 0.77). Dry foods presented higher concentrations of most TM (P < 0.05) than wet foods (P < 0.05). Among the carbohydrate sources, there were the highest levels of all TM except cobalt, mercury, and nickel in wheat bran (P < 0.05), while among the protein sources, in general, animal by-products had higher TM concentrations than plant-based ingredients. Pork fat had higher concentrations of arsenic, mercury, and antimony than fish oil and poultry fat. It was concluded that the pet foods evaluated in this study presented high concentrations of the following TM: aluminum, mercury, lead, uranium, and vanadium.

A Comparison of Key Essential Nutrients in Commercial Plant-Based Pet Foods Sold in Canada to American and European Canine and Feline Dietary Recommendations.

Simple SummaryPlant-based pet foods appear to be growing in popularity, but it is unclear how suitable these products are for dogs and cats, considering both species naturally consume diets rich in, or exclusively comprised of, animal tissues. Laboratory analyses of essential nutrients were performed on 26 plant-based diets available in Ontario, Canada in 2018, including 18 canine products (13 products labelled for adult maintenance, four for all life stages, one for puppy growth), 5 feline products (two for adult maintenance and three for all life stages), and 3 products labelled for both dogs and cats (one for adult maintenance and two for all life stages). The nutrient measurements were compared to industry standard nutrient profiles. Four products met the recommendations of the Association of American Feed Control Officials and one product the nutrient recommendations of the European Pet Food Industry Federation for adult dogs. No diets met recommended nutrient content for adult cats or growing puppies or kittens. Nutrients most commonly found to be insufficient were: sulfur amino acids, taurine, arachidonic acid, EPA and DHA, calcium phosphorus and vitamin D. These nutrients are all typically found in animal tissues, though non-animal sources are available, and require careful formulation or supplementation in products made without animal-derived ingredients. Compliance with Canadian labelling regulation and guidelines was poor. These problems do not appear to be exclusive to plant-based foods and have been demonstrated previously in commercially available animal-based products as well. This study demonstrates areas where manufacturers of plant-based pet foods must improve formulation and/or manufacturing practices to produce products appropriate for feeding cats and dogs.Plant-based foods intended for feeding dogs and cats are available in Canada, though few studies have examined the suitability of plant-based foods for dogs and cats. All commercial plant-based extruded and wet pet food products available in Ontario, Canada, in 2018 (n = 26) were acquired and analysed for energy, crude protein, crude fat, crude fibre, ash, amino acids, fatty acids, minerals and vitamins A, B12, D2 and D3. Results were compared with recommendations of the Association of American Feed Control Officials (AAFCO) and the European Pet Food Industry Federation (FEDIAF). Thirteen products were labelled for adult canine maintenance, four for canine all life stages, one for puppy growth, two for adult feline maintenance, three for feline all life stages, one for adult maintenance of dogs and cats and two for all life stages of dogs and cats. Four products met AAFCO and one product met FEDIAF nutrient recommendations for canine maintenance. No diets met AAFCO or FEDIAF recommendations for feline maintenance or growth for either species. Nutrients most commonly found insufficient were: sulfur amino acids, taurine, arachidonic acid, EPA and DHA, calcium phosphorus and vitamin D. There were no nutrients unable to be provided from non-animal sources. Compliance with labelling guidelines was also poor, similar to other findings with commercial animal-based pet products. The results from this study indicate areas where producers of plant-based pet foods must improve to meet the industry recommended nutrient profiles and labelling requirements.

The Effects of 7 Days of Feeding Pulse-Based Diets on Digestibility, Glycemic Response and Taurine Levels in Domestic Dogs.

Grain-based carbohydrate sources such as rice comprise 30–50% of commercial pet foods. Some pet foods however have removed the use of grains and have instead incorporated pulses, such as peas and lentils, resulting in grain-free diets. The hypothesis was dog diets with higher levels of dietary fiber will produce a low glycemic response due to decreased rates of digestion and lowered bioavailability of all macronutrients and increased fecal bile salt excretion. This in turn was hypothesized to produce lower plasma concentrations of cysteine, methionine and taurine after 7 days of feeding each test diet in dogs. Six diets were formulated at an inclusion level of 20% available carbohydrate, using white rice flour (grain) or whole pulse flours from smooth pea, fava bean, red lentil or 2 different wrinkled pea varieties (CDC 4,140–4 or Amigold) and fed to beagles in a randomized, cross-over, blinded design. After 7 days feeding each diet, fasting blood glucose was the lowest in the lentil (3.5 ± 0.1 mmol/L) and wrinkled pea (4,140–4; 3.6 ± 0.1 mmol/L) diet periods, while peak glucose levels was lowest after feeding the lentil diet (4.4 ± 0.1 mmol/L) compared to the rice diet. Total tract apparent digestibility of all macronutrients as well as taurine differed among diets yet plasma taurine was not outside normal range. Decreased macronutrient and amino acid digestibility was associated with increasing amylose and dietary fiber content but the specific causative agent could not be determined from this study. Surprisingly, digestibility decreases were not due to increased bile salt loss in the feces since increasing dietary fiber content led to decreased fecal bile salt levels. In conclusion, although pulse-based canine diets have beneficial low glycemic properties, after only 7 days, these pulse-based diets decrease macronutrient and amino acid digestibility. This is likely related at least in part to the lower animal protein content, but on a long-term basis could put domestic dogs at risk for low taurine and dilated cardiomyopathy.

Using a next-generation sequencing approach to DNA metabarcoding for identification of adulteration and potential sources of mercury in commercial cat and dog foods.

Studies have demonstrated that some commercial pet (i.e., cat and dog) food products contain high concentrations of mercury (Hg), and some products have Hg concentrations that are higher than expected based on the ingredients included in the package ingredient list. Additionally, concentrations of methylmercury, a particularly toxic form of Hg commonly associated with fish-based ingredients, are largely unstudied despite the widespread use of such ingredients in pet food products. This study aimed to quantify total Hg and methylmercury in a variety of commercial pet food products (n=127), and use genetic tools to determine if specific ingredients contributed to high Hg concentrations in the final product. Results indicate that total Hg concentrations were above suggested maximum tolerable limits in three of the tested pet food products, and that methylmercury concentrations were at safe levels in all tested products. Next-generation amplicon sequencing using ten barcode primers was conducted to target distinct taxa and to determine if one primer set outperformed the others in amplifying the often heavily degraded DNA found in pet food products. The 16sUniF_16sUniR primer set generated a relatively higher number of reads across the broadest set of taxa, although several of the primer sets were useful in identifying common animal- and plant-based ingredients in commercial pet food products. Combined with the Hg results, it was demonstrated that pet food product ingredients are consistent among and between product lots. However, these results also revealed that adulteration is prevalent in pet food products.

A Survey among Dog and Cat Owners on Pet Food Storage and Preservation in the Households.

Simple SummaryProper dog and cat food preservation is fundamental to ensure the best quality of the diet right up to the moment of feeding, given that nutritional value, safety and sensory properties can be irreparably damaged by environment and time. To this end, a survey was conducted to explore how pet owners store both commercial and home-prepared diets. On the whole, despite the wide variability of practices adopted, most of the 2221 respondents implemented good storage management. Room temperature was the most overlooked parameter during storage, and this may be a cause of concern because exposure to warmth can enhance rancidity, especially in diet formulations rich in fats and oils. For this reason, veterinarians should provide precise instructions on storing perishable ingredients to those who feed home-prepared diets. Moreover, respondents of older generations appeared to distrust the use of preservatives in commercial pet foods and often deemed their inclusion harmful and unnecessary. Pet food manufacturers should discourage skepticism of the additives crucial to long-term commercial pet food conservation through better communication.Background: Pet food storage plays a crucial role in maintaining the nutritional and sensory properties of purchased products over time. Methods: An online survey was developed to collect data regarding owners’ storage habits for both commercial and home-made diets. Results: The questionnaire was completed by 1545 dog owners and 676 cat owners. Pet and owner age played roles in the choice of the type of diet (commercial vs. home-cooked vs. raw meat-based) adopted. Kibble feeders (75.7%) usually bought one (50.1%) or two (24.6%) packages at a time, and most pets (64.4%) took a minimum four weeks to consume an entire bag. Almost half of the owners (43.5%) used a container to store pet food (plastic bins for 79.5%). Pet food was commonly stored in the kitchen (45.1%) and not exposed to direct light (94.5%); 23.6% of the kibble feeders said it might be exposed to high temperatures. Most commercial pet food feeders (67.3%) considered preservatives a potential health risk for pets. Among homemade diet feeders, 38.6% stored fish oil at room temperature. Conclusions: Pet owners should be educated in proper food storage management when receiving feeding instructions from veterinarians. More comprehensive information on the nature and importance of additives in pet food should be promoted by manufacturers.