Evaluating pet foods: how confident are you when you recommend a commercial pet food?

Vegan versus meat-based dog food: Guardian-reported health outcomes in 2,536 dogs, after controlling for canine demographic factors

To compare health outcomes between dogs fed meat and vegan diets, we surveyed 2,536 dog guardians who provided data and opinions about dogs fed conventional meat (1,370 = 54 %), raw meat (830 = 33 %) or vegan (336 = 13 %) diets for at least one year. We examined seven general indicators of illness: increased numbers of veterinary visits, medication use, progression onto a therapeutic diet after initial maintenance on a vegan or meat-based diet, reported veterinary assessment of being unwell, reported veterinary assessment and guardian opinion of increased illness severity, and number of health disorders per unwell dog. We also considered the prevalence of 22 specific health disorders, based on reported veterinary assessments. In each dietary group the proportions of dogs considered to have suffered from health disorders were: conventional meat - 49 %, raw meat - 43 % and vegan - 36 %. Probabilities of suffering from a disorder respectively appeared highest in dogs fed conventional meat for 11 disorders, raw meat for eight disorders, and vegan diets for three disorders. We conducted regression analyses to control for differences in medically-relevant canine demographic variables, including age, sex, neutering status, breed size and unusually high exercise levels. Dogs fed vegan diets had the best health outcomes. This trend was clear and consistent, with dogs fed vegan diets usually having substantial and statistically significant decreases in risks of these seven general indicators of illness. These ranged from 14.4 % to 51.3 % compared to dogs fed conventional meat-based diets. For six specific disorders, vegan diets were associated with statistically significant risk reductions of 50 %-61 % compared to dogs fed conventional meat. After pooling our results with related studies published to date, vegan dog food was consistently associated with lowered risks of multiple specific health disorders. No health disorder was consistently more prevalent in dogs fed vegan diets.

Individual and combined occurrences of the prevalent mycotoxins in commercial feline and canine food

Mycotoxins, such as aflatoxin B1 (AFB1), deoxynivalenol (DON), fumonisins (FBs), ochratoxin A (OTA), T-2 toxin (T-2), and zearalenone (ZEN), can contaminate animal feeds and pose risks to animal health and production performance. These mycotoxins are commonly found in cereals and grains, with the increased use of cereals in pet food, there is a rising concern about mycotoxin contamination among pet owners. To address this, we analyzed imported brands of feline and canine food from the Chinese market produced in 2021-2022. Ninety-three samples were analyzed, comprising 45 feline food and 48 canine food samples. Among them, 14 were canned food and 79 were dry food. The results indicate that AFB1, DON, FBs, OTA, T-2, and ZEN occurred in 32.26%, 98.92%, 22.58%, 73.12%, 55.91%, and 7.53% of the samples, respectively. The most prevalent mycotoxin was DON, followed by OTA, T-2, AFB1, and FBs, whereas ZEN was less frequently detected. The mean concentrations of the six mycotoxins in pet feed samples were 3.17 μg/kg for AFB1, 0.65 mg/kg for DON, 2.15 mg/kg for FBs, 6.27 μg/kg for OTA, 20.00 μg/kg for T-2, and 30.00 μg/kg for ZEN. The levels of mycotoxins were generally below the limits of the Pet Feed Hygiene Regulations of China and the EU. Notably, a substantial majority of the pet food samples (88 out of 93) were contaminated by two or more mycotoxins. AFB1, FBs, OTA, and ZEN occurred slightly more often in feline food than in canine food. Except for OTA, the contamination rates for the other five mycotoxins in canned food were lower than those in dry food. Moreover, except for AFB1, the levels of the other five mycotoxins in canned foods were lower than those in dry foods. This study highlights the widespread contamination of pet foods with mycotoxins, which poses a significant risk to pets from continuous exposure to multiple mycotoxins.

Insights to Study, Understand and Manage Extruded Dry Pet Food Palatability

Pet food production is a fast-growing industry. While extruded dry pet food is the favored pet food due to its convenience of use, it may have poorer palatability than other pet foods such as wet pet foods. However, palatability plays a pivotal role in meeting nutritional requirements or providing therapeutic benefits in cats and dogs, as it ensures food acceptance. Thus, both academics and manufacturers conduct routine palatability tests to assess acceptance and preference of products among pets, alongside sensory analyses involving human panels. Palatability is greatly influenced by species-specific and environmental factors in cats and dogs. The review will hence present the current knowledge on palatability assessment and animal food perception; it will then aim to explore strategies for effectively managing palatability in dry pet food by examining the impact of key ingredients and process parameters on the finished product's palatability. Moreover, the demands and needs for sustainable and healthier products as well as supply constraints present novel challenges and opportunities for academics and manufacturers.

Case report: Infection with Dicrocoelium dendriticum in a Japanese Chin dog

Dicrocoelium dendriticum is a trematode colonising the bile ducts of herbivores. Coproscopic findings in dogs are usually considered gastrointestinal passages of eggs after ingestion of unheated liver tissue or infected ruminant faeces. Here, a Japanese Chin presented with diarrhoea and weight loss. Eggs comparable to D. dendriticum were detected in faeces and infection was confirmed via PCR and by ruling out differential diagnoses. Egg excretion continued for a period of 10 months. Praziquantel (50 mg/kg body weight [BW]) was administered orally for four consecutive days. Egg excretion 10 days after treatment entailed further treatments with 100 mg/kg BW, again for four days. Faecal samples were negative ten days and four weeks afterwards, diarrhoea resolved, and the dog gained weight. In cases of repeated coproscopic positivity for D. dendriticum, an infection with dogs acting as definitive hosts should be considered. Treatment with praziquantel at a higher dosage may be required.

Assessment of the antifungal efficacy of whey fermentate alone or in combination with citrus extract to control Aspergillus flavus mold in semi-moist pet food for dogs

Semi-moist pet foods contain moisture levels ranging from 15 to 40%, making them ideal for mold growth and mycotoxin production. To control spoilage, synthetic mold inhibitors such as potassium sorbate have been used, but consumers prefer "natural" preservatives. Whey fermentate (WPF) is an efficient antifungal, but it requires large doses. Therefore, the objective of this study was to determine the antifungal effect of WPF alone or in combination with citrus extract oil (CEX) against Aspergillus flavus in semi-moist pet food. Nutritionally complete semi-moist pet foods were produced with WPF alone [0.25, 0.5, and 1.0% (w/w)] and in combination with CEX; 0.25% WPF+ 0.015% CEX, 0.25% WFP+ 0.15% CEX, 0.5% WPF+ 0.015% CEX, and 0.5% WFP+ 0.15% CEX (w/w). The negative control (NC) contained no antifungal additive and the positive control (PC) had potassium sorbate (0.1% w/w). The semi-moist pet food was thermally formed and was cut into 3 cm × 3 cm square pieces. Individual food pieces were inoculated with 0.1 mL of Aspergillus flavus (ATCC 204304) to achieve a final concentration of ~5.0 log CFU/piece. The inoculated pieces were individually incubated at 25°C. Fungal analysis was performed on day 3, 6, 9, 12, 15, 18, 21, 24, and 28 by surface plating on Potato Dextrose Agar (PDA) followed by incubation at 25°C for 72 h. The total log reductions were calculated by subtracting the initial inoculum from the final log counts on day 28. Higher log reductions of Aspergillus flavus (p < 0.05) were observed when WPF at 0.25 and 0.5% was combined with 0.15% CEX compared to when 0.015% CEX was used individually. All treatments were different from the NC (p < 0.05). Citrus extract at 0.15% potentiated the antifungal effect of WPF at 0.5% to give a similar log reduction (p > 0.05) to WPF at 1.0% in the food. In conclusion, CEX potentiated the antifungal efficacy and reduced the dose of WPF required to control Aspergillus flavus in semi-moist dog food.

Vegan versus meat-based cat food: Guardian-reported health outcomes in 1,369 cats, after controlling for feline demographic factors

Increasing concerns about environmental sustainability, farmed animal welfare and competition for traditional protein sources, are driving considerable development of alternative pet foods. These include raw meat diets, in vitro meat products, and diets based on novel protein sources including terrestrial plants, insects, yeast, fungi and potentially seaweed. To study health outcomes in cats fed vegan diets compared to those fed meat, we surveyed 1,418 cat guardians, asking about one cat living with them, for at least one year. Among 1,380 respondents involved in cat diet decision-making, health and nutrition was the factor considered most important. 1,369 respondents provided information relating to a single cat fed a meat-based (1,242-91%) or vegan (127-9%) diet for at least a year. We examined seven general indicators of illness. After controlling for age, sex, neutering status and primary location via regression models, the following risk reductions were associated with a vegan diet for average cats: increased veterinary visits- 7.3% reduction, medication use- 14.9% reduction, progression onto therapeutic diet- 54.7% reduction, reported veterinary assessment of being unwell- 3.6% reduction, reported veterinary assessment of more severe illness- 7.6% reduction, guardian opinion of more severe illness- 22.8% reduction. Additionally, the number of health disorders per unwell cat decreased by 15.5%. No reductions were statistically significant. We also examined the prevalence of 22 specific health disorders, using reported veterinary assessments. Forty two percent of cats fed meat, and 37% of those fed vegan diets suffered from at least one disorder. Of these 22 disorders, 15 were most common in cats fed meat, and seven in cats fed vegan diets. Only one difference was statistically significant. Considering these results overall, cats fed vegan diets tended to be healthier than cats fed meat-based diets. This trend was clear and consistent. These results largely concur with previous, similar studies.

Nutritional evaluation of new alternative types of dog foods including raw and cooked homemade-style diets

BACKGROUND

New alternative types of pet foods such as raw and cooked homemade-style diets containing human food ingredients have been introduced due to a trend of pet humanization and diversification of consumer needs.

OBJECTIVES

To evaluate nutritional adequacy of new alternative types of dog foods containing human food ingredients as maintenance diets for dogs.

METHODS

Eleven homemade-style foods for adult dogs were purchased from online channel in Korea and analyzed to evaluate nutritional adequacy for adult dogs. Nutrients analyzed included crude protein, amino acids, crude fat, fatty acids, and minerals.

RESULTS

Crude protein and amino acids in all products satisfied Association of American Feed Control Officials (AAFCO) requirements. Crude fat in one of 11 products did not meet AAFCO requirements. The most deficient minerals were selenium (10 of 11, 90.9%), copper (five of 11, 45.5%), zinc (five of 11, 45.5%), potassium (three of 11, 27.3%), calcium (three of 11, 27.3%), iron (two of 11, 18.2%), and magnesium (one of 11, 9.1%). Six products were not in the range of the recommended Ca:P ratio in AAFCO dog food maintenance nutrient profiles.

CONCLUSIONS

This study performed nutritional evaluation of raw and cooked homemade-style foods as maintenance diets for adult dogs. Some nutritional inadequacies were observed including some minerals, Ca:P ratio, and omega-6:omega-3 fatty acid ratio, although three products (26.2%) satisfied the AAFCO standard except selenium. Overall, the data suggest a need for accurate nutritional adequacy statement for consumers based on proper methods to validate the formula.

Evaluation of the Chemosensoric Properties of Commercially Available Dog Foods Using Electronic Sensors and GC-MS/O Analysis

Pet owners think of their animals as part of their family, which further promotes the growth of the pet food market, encouraging pet owners to select nutritious, palatable, and high-quality foods for pets. Therefore, the evaluation of taste and volatile compounds in pet foods is essential to improve palatability. In this study, the sensory characteristics of taste and odor compounds in 10 commercially available dry dog foods were investigated using electronic tongue (E-tongue), electronic nose (E-nose), gas chromatography-mass spectrometry (GC-MS), and gas chromatography-olfactometry (GC-O). Dry dog foods were separated based on the sensory properties of taste and volatile compounds through the multivariate analysis of integrated results of the E-tongue and E-nose. A total of 67 odor active compounds were detected through GC-MS and GC-O, and octanal, nonanal, 2-pentyl furan, heptanal, and benzaldehyde were identified as key odor compounds which may have positive effects on food intake. The multivariate analysis was used to classify samples based on key odor compounds. Volatile compounds responsible for aroma properties of samples were evaluated using GC-O and multivariate analysis in this present study for the first time. These results are expected to provide fundamental data for sensory evaluation in producing new dog foods with improved palatability.

Biogenic Amine Content Analysis of Three Chicken-Based Dry Pet Food Formulations

The pet food market is constantly expanding, and more and more attention is paid to the feeding of pets. Dry foods stand out and are often preferred due to their long shelf life, ease of administration, and low cost. In this context, dry foods are formulated from fresh meats, meat meals, or a mix of the two. These raw materials are often meat not fit for human consumption; they might be subject to contamination and proliferation of microorganisms which, by degrading the organic component, can lead to the formation of undesirable by-products such as biogenic amines. These nitrogenous compounds obtained by decarboxylation of amino acids can therefore be found in high-protein foods, and their ingestion in large quantities can cause intoxication and be harmful. This study aims at analyzing the possible presence of biogenic amines in three different formulations of chicken-based kibbles for pets: one obtained from fresh meat, one from meat meal, and one from a mix of the two. This study is also focused on the presence of free amino acids as they represent the key substrate for decarboxylating enzymes. Mass spectrometry (Q-TOF LC/MS) was used to analyze the presence of biogenic amines and free amino acids. The results show that fresh-meat-based products have a lower content of biogenic amines, and at the same time a higher quantity of free amino acids; on the contrary, meat-meal- and mix-based products have a greater quantity of biogenic amines and a lower concentration of free amino acids, suggesting that there has been a higher microbial proliferation as proved by the total aerobic mesophilic bacteria counts. It is therefore clear that fresh-meat-based kibbles are to be preferred when they are used for preparing dry pet food due to the lowest concentration of biogenic amines.

Natural mycotoxin contamination in dog food: A review on toxicity and detoxification methods

Nowadays, the companion animals (dogs or other pets) are considered as members of the family and have established strong emotional relationships with their owners. Dogs are long lived compared to food animals, so safety, adequacy, and efficacy of dog food is of great importance for their health. Cereals, cereal by-products as well as feedstuffs of plant origin are commonly employed food resources in dry food, yet are potential ingredients for mycotoxins contamination, so dogs are theoretically more vulnerable to exposure when consumed daily. Aflatoxins (AF), deoxynivalenol (DON), fumonisins (FUM), ochratoxin A (OTA), and zearalenone (ZEA) are the most frequent mycotoxins that might present in dog food and cause toxicity on the growth and metabolism of dogs. An understanding of toxicological effects and detoxification methods (physical, chemical, or biological approaches) of mycotoxins will help to improve commercial ped food quality, reduce harm and minimize exposure to dogs. Herein, we outline a description of mycotoxins detected in dog food, toxicity and clinical findings in dogs, as well as methods applied in mycotoxins detoxification. This review aims to provide a reference for future studies involved in the evaluation of the risk, preventative strategies, and clear criteria of mycotoxins for minimizing exposure, reducing harm, and preventing mycotoxicosis in dog.

Effects of liquid smoke preparations on shelf life and growth of wild type mold and Aspergillus flavus in a model semi moist pet food

Liquid smoke is a naturally derived flavor component and preservative with known antimicrobial properties. To our knowledge, there is a paucity of information on antifungal potential of liquid smoke against toxigenic fungi like Aspergillus flavus that produce mycotoxins in human and pet foods. Semi-moist pet food with high moisture content (20-30%) is susceptible to mold contamination and requires intervention. The objectives of this study were to determine the effects of liquid smoke preparations on the growth of wild-type mold and A. flavus in semi-moist pet food. Semi-moist pet food was formulated with eight different liquid smoke preparations (S1-S8) containing varying amounts of organic acids, phenol and carbonyl compounds (ranging from low to high) at 0% (untreated), 0.5, 1, 2, and 4% (w/w). A positive control consisted of 0.2% potassium sorbate known to inhibit mold growth. Shelf life was estimated by storing the samples at 28°C and 65-70% RH over 30 days and recording the number of days until the appearance of visible wild-type mold. In another experiment, samples were spot inoculated with A. flavus (∼10,000 CFU/mL), incubated at 25°C, and analyzed for fungal growth at sampling intervals of 2 days over a 35-day period. Liquid smoke at 0.5, 1, 2, and 4% extended the shelf life of samples on an average by a total of 11.6, 12.5, 17.2, and 24.1 days when compared to the untreated samples (7.7 days). The smoke preparations Cloud S-C100 (S3) and Code-10 (S6) (high carbonyl, medium/low phenol) were the most effective (P < 0.05) in prolonging the number of days to visible mold growth (26-28 days). In the challenge study with A. flavus, Cloud S-C100 (S3), Cloud S-AC15 (S8) (high to medium carbonyl, low phenol), and Code 10 (S6) (base smoke) reduced (P < 0.05) mold counts by 1.0, 1.7, and 2.5 logs when compared to the untreated samples at 1, 2, and 4%, respectively. Addition of smoke at 0.5% did not reduce mold counts. The carbonyl preparations of liquid smoke were the most effective at enhancing shelf life of semi-moist pet food, and at inhibiting A. flavus growth.

Determining the protocol requirements of in-home dog food digestibility testing

In-home pet food testing has the benefit of yielding data which is directly applicable to the pet population. Validated and standardised in-home test protocols need to be available, and here we investigated key protocol requirements for an in-home canine food digestibility protocol. Participants were recruited via an online survey. After meeting specific inclusion criteria, sixty dogs of various breeds and ages received, during 14 consecutive days, a relatively low and high digestible complete dry extruded food containing titanium (Ti) dioxide. Both foods were given for 7 d in a cross-over design. Owners collected faeces daily allowing daily faecal Ti concentrations and digestibility of nitrogen (N), dry matter (DM), crude ash, organic matter (OM), crude fat (Cfat), starch and gross energy (GE) to be determined. Faecal Ti and digestibility values for all nutrients were not different (P > 0·05) from the second day onwards after first consumption for both foods. One day of faecal collection yielded reliable digestibility values with additional collection days not reducing the confidence interval around the mean. Depending on the accepted margin of error, the food and the nutrient of interest, the minimal required sample size was between 9 and 43 dogs. Variation in digestibility values could in part be explained by a dog's neuter status (N, crude ash) and age (crude ash, Cfat) but not sex and body size. Future studies should focus on further identifying and controlling sources of variation to improve the in-home digestibility protocol and reduce the number of dogs required.

From Nutritional Adequacy to Hygiene Quality: A Detailed Assessment of Commercial Raw Pet-Food for Dogs and Cats

Raw meat-based diets (RMBDs) are widely used as unconventional diets for dogs and cats at different life stages, despite concerns regarding nutritional adequacy and microbial contamination. The aim of this study was to evaluate both the nutritional and hygiene quality profile of RMBDs purchased in Germany. For this purpose, crude nutrients were assessed in 44 RMBDs and compared to declared values. In addition, selected minerals were determined in 31 RMBDs labelled as complete and compared to the minimum requirement (MR) for intended species and life stages. Aerobic colony count (ACC) and Enterobacteriaceae were used to assess the hygiene quality of 37 commercial RMBDs, while the presence of Salmonella spp. was examined in 10 products. Fat and protein content exceeded tolerated deviation from declared values in 33% and 45% of RMBDs, respectively. Each RMBD showed at least one concern regarding nutrient content. The RMBDs had high fat contents (mean 69, range 33−95 g/Mcal) that were negatively correlated with protein (r = −0.74, p < 0.0001). Considerable contaminations by ACC and Enterobacteriaceae were found (2.61 × 108 ± 3.63 × 108 and 3.61 × 106 ± 8.39 x106 CFU/g, respectively). A higher count of Enterobacteriaceae was detected in a frozen RMBDs made of poultry or carcasses from different animals, compared to the thawed counterpart (p = 0.003), as well as compared to other sources, such as beef, horse, and lamb, regardless of the storage condition. Salmonella spp. were found in 2/10 RMBDs. This study confirmed that feeding commercial RMBDs might pose a risk to pet health.

The Hard Choice about Dry Pet Food: Comparison of Protein and Lipid Nutritional Qualities and Digestibility of Three Different Chicken-Based Formulations

Simple Summary

The majority of pet food currently on the market is represented by dry food thanks to its practicality and long shelf life. Dry pet food production consists of several processes that can have different effects on nutrient bioavailability and digestibility. The aim of this study was to analyze the nutritional quality of three different chicken-based formulations, consisting of fresh meats, meat meals, or a mix of these two from a protein, lipid, and in vitro digestibility point of view. The results show that the fresh chicken-meat-based formulation appears to be the preferable choice when proteins, lipids, and in vitro digestibility are taken into account. Moreover, the soluble protein content estimated by the Bradford assay is found to correlate well with the total protein content and in vitro digestibility.

Abstract

Dry pet food, made of fresh meats and especially meat meals, represents one of the main types of complete food available on the market by virtue of its practicality and long shelf life. The kibble production process includes mixed thermal and mechanical treatments that help to improve the palatability and durability of the final product but may have undesirable effects on nutrient bioavailability and digestibility. An analysis of the protein and lipid content of different dry pet food formulations, together with an in vitro digestibility analysis, can reveal which formulation can provide a more nourishing diet for pets. In this study, a quantitative and qualitative analysis was performed on three different formulations of chicken-based dry pet food, consisting of fresh meats, meat meals, or a mix of these two. The soluble protein concentration was determined by the Bradford assay, while the crude protein content was assessed through the Kjeldahl method. Quadrupole time-of-flight liquid chromatography/mass spectrometry (Q-TOF LC/MS) was used to analyze the amino acid (AA) and lipid compositions. Finally, a gastric and small intestinal digestion simulation was used to determine the in vitro digestibility. The results show that dry pet food consisting only of chicken fresh meats has the highest content of soluble protein; it also contains more Essential AAs, Branched-Chain AAs, and Taurine, as well as a greater quantity of monounsaturated and polyunsaturated fatty acids. In addition, its in vitro digestibility was the highest, exceeding 90% of its dry weight, in agreement with the soluble protein content. These findings thus make the fresh-meat-based formulation a preferable choice as dry pet food.

Vegan versus meat-based dog food: Guardian-reported indicators of health

Alternative pet foods may offer benefits concerning environmental sustainability and the welfare of animals processed into pet foods. However, some worry these may compromise the welfare of pets. We asked 2,639 dog guardians about one dog living with them, for at least one year. Among 2,596 involved in pet diet decision-making, pet health was a key factor when choosing diets. 2,536 provided information relating to a single dog, fed a conventional meat (1,370 = 54%), raw meat (830 = 33%) or vegan (336 = 13%) diet for at least one year. We examined seven general indicators of ill health: unusual numbers of veterinary visits, medication use, progression onto a therapeutic diet after initial maintenance on a vegan or meat-based diet, guardian opinion and predicted veterinary opinion of health status, percentage of unwell dogs and number of health disorders per unwell dog. Dogs fed conventional diets appeared to fare worse than those fed either of the other two diets. Dogs fed raw meat appeared to fare marginally better than those fed vegan diets. However, there were statistically significant differences in average ages. Dogs fed raw meat were younger, which has been demonstrated to be associated with improved health outcomes. Additionally, non-health related factors may have improved apparent outcomes for dogs fed raw meat, for three of seven general health indicators. We also considered the prevalence of 22 specific health disorders, based on predicted veterinary assessments. Percentages of dogs in each dietary group considered to have suffered from health disorders were 49% (conventional meat), 43% (raw meat) and 36% (vegan). Significant evidence indicates that raw meat diets are often associated with dietary hazards, including nutritional deficiencies and imbalances, and pathogens. Accordingly, the pooled evidence to date indicates that the healthiest and least hazardous dietary choices for dogs, are nutritionally sound vegan diets.

Potential Owner-Related Risk Factors That May Contribute to Obesity in Companion Dogs in Aotearoa New Zealand

Approximately a third of all Aotearoa New Zealand (NZ) households include a dog, with 28% of these dogs being overweight or obese, conditions that are associated with many serious health issues. Therefore, healthy weight interventions that focus on the owner’s role are of great importance to companion animal welfare in NZ. Accordingly, the present study explores the feeding practices associated with NZ dogs and identifies potential owner-related risk factors contributing to these animals being overweight or obese. The current study used data collected from a survey conducted online in 2019 between January and March of NZ residents over 18. Along with demographic questions, the respondents were asked questions regarding their dog’s body condition and diet questions related to the body. Nearly a quarter (26%, n = 609) of the survey participants (n = 2358) owned at least one dog. The current study reported that increasing age range, household income and the number of children increased the likelihood of having a dog while increasing qualification level and living in a town/city decreased the likelihood. The majority of the respondents fed their dog(s) treats (59%) and 85% fed them specialised food bought from a pet shop, veterinary clinic and/or different online sources. Just over a third of the participant (39%) reported that they fed their dog(s) biscuits from the supermarket, 36% fed their dog(s) raw meat, and 34% of respondents fee their dog(s) table scraps/human food. These results suggest that many dog owners feed their dog(s) various food types, making it a challenging task to determine the exact amount required from each type in order not to exceed caloric intake. Disagreement regarding the correct body condition were reported among twenty per cent of the respondents. This finding indicates a knowledge gap among the NZ dog-owning population that may negatively affect their dogs’ welfare and wellbeing. Future research into pro-equity approaches to address these issues is needed so that dogs in NZ can live not only a good life but also their best life.

It Keeps the Good Boy Healthy from Nose to Tail: Understanding Pet Food Attribute Preferences of US Consumers

The study provides insights for marketing managers in specialized pet supplies retailers, as well as for vets and animal welfare organizations. This study proposes a model that investigates the importance pet owners place on convenience, natural ingredients, and value and health claims as product attributes. For this purpose, an online survey with a sample size of 206 pet-owning US residents was conducted. Partial least squares structural equation modelling shows that pet food purchase involvement positively impacts subjective and objective knowledge about pet food. Subjective knowledge appears to be the strongest factor impacting the importance consumers place on all three attributes. This is followed by objective knowledge. Socio-demographic factors such as gender, age, income, and education appear to have a limited impact as predictors for the importance consumers place on the product attributes.

Contents of Polyamines and Biogenic Amines in Canned Pet (Dogs and Cats) Food on the Austrian Market

Biogenic amines accumulate in proteinaceous raw materials used for pet food production. In canned, sterilized food, amine levels of the ingredients are preserved and may both be indicative of hygiene deficiencies in the ingredients as well as for potential adverse effects to the animals feeding on it. We determined the contents of biogenic amines and polyamines (dansyl derivatives, high performance liquid chromatography) in a variety of canned food for dogs (n = 72) and cats (n = 114) on the Austrian market and compared the results with common quality indices. Contents of putrescine, cadaverine, and tyramine were below the limit of detection in >70% of samples (maximum values: 21.5, 98.4 and 32.5 mg/kg wet weight, respectively). Median contents of histamine, spermidine, and spermine were 14.5, 12.7, and 29.4 mg/kg, and maximum values were 61.6, 28.2, and 53.6 mg/kg wet weight, respectively. The sum of (putrescine + cadaverine + histamine + tyramine) was >50 mg/kg in 22.6% of samples. The biogenic amine index exceeded “1” in 26.7% of samples. Whilst cat food contained significantly higher amounts of tyramine, dog food contained significantly higher amounts of histamine and spermine. In canned cat food, the ingredient “fish” was identified as a statistically significant risk factor for a biogenic amine index > 1 (relative risk = 3.0 (95% confidence interval: 1.8–5.5)) and for (putrescine + cadaverine + histamine + tyramine) exceeding 50 mg/kg (relative risk = 2.4 (95% confidence interval: 1.2–4.6)), due to higher contents of cadaverine in food samples containing fish. While all samples met the limits suggested in pet food production, we could demonstrate that the inclusion of fish in the formulation bears a significant risk for higher cadaverine contents.

Vegan versus meat-based pet foods: Owner-reported palatability behaviours and implications for canine and feline welfare

Consumer suspicion of conventional pet foods, along with perceived health benefits of alternative diets, are fuelling development of the latter. These include raw meat diets, in vitro meat products, and diets based on novel protein sources such as terrestrial and marine plants, insects, yeast and fungi. However, some claim vegan diets may be less palatable, or may compromise animal welfare. We surveyed 4,060 dog or cat guardians to determine the importance to them of pet food palatability, and the degree to which their animals displayed specific behavioural indicators of palatability at meal times. Guardians were asked to choose one dog or cat that had been within their household for at least one year, and not on a prescription or therapeutic diet. Of 3,976 respondents who played some role in pet diet decision-making, palatability was the third most important among 12 factors cited as important when choosing pet diets. For 1,585 respondents feeding conventional or raw meat diets, who stated they would realistically consider alternative diets, palatability was the fourth most important among 14 desired attributes. For the 2,308 dogs included, reported observations of 10 behavioural indicators of palatability at meal times reliably indicated significant effects of increased reports of appetitive behaviour by dogs on a raw meat diet, as opposed to a conventional diet. There was no consistent evidence of a difference between vegan diets and either the conventional or raw meat diets. For the 1,135 cats included, reported observations of 15 behavioural indicators indicated that diet made little difference to food-oriented behaviour. Based on these owner-reported behaviours, our results indicate that vegan pet foods are generally at least as palatable to dogs and cats as conventional meat or raw meat diets, and do not compromise their welfare, when other welfare determinants, such as nutritional requirements, are adequately provided.

Nutritional evaluation of commercial dry dog foods available on the Czech market

The evaluation of the quality of commercial diets is a topic of interest to dog owners and veterinarians. The aims of the study were to determine proximate analysis, metabolizable energy and some amino acids in dry dog diets for different ages, divided into three groups G1 (low price, grains included), G2 (medium price, grains included) and G3 (high price, grain-free). The hypothesis was tested that there are significant differences in the analysed values between dry dog diets from different price categories and between grain-free and grain-containing diets. Furthermore, the analysed values were compared with AAFCO and FEDIAF recommendations and with label values guaranteed by manufacturers to see whether there are any deviations. We analysed 60 samples of complete dry dog diets purchased in the Czech Republic, using the standard AOAC methods of proximate analysis. Metabolizable energy was calculated using the NRC equation, and 30 samples were analysed for selected amino acids. The results showed that there are significant differences in protein and amino acid contents between grain-free (G3) and grain-containing (G1,2) dog diets. G3 diets had significantly (p < 0.01) higher crude protein and essential amino acid contents. No significant differences were found between grain-containing diets G1 and G2. The results may indicate a higher proportion of animal components and a lower content of carbohydrates in G3 diets. Most of the tested dog diets met the AAFCO and FEDIAF recommendations. There were only a few deviations in threonine in G1 and G2 diets for growing dogs.

Rapid and Low Cost Determination of Total Mercury in Cat Foods by Photochemical Vapor Generation Coupled to Atomic Absorption Spectrometry

A rapid and low-cost method for determination of total mercury (THg) in cat food was developed based on photochemical vapor generation (PVG) coupled to cold vapor atomic absorption spectrometry (CVAAS). Cat food samples with ingredients based on tuna fish and other seafood were investigated. Organic acid precursor and concentration for radical generation and Hg photoreduction, sample UV irradiation time, and carrier gas flow were optimized. Highest PVG efficiency was achieved using 10% v v^-1 formic acid, 4-s UV irradiation time, and a carrier gas flow of 50 mL min^-1. The calibration function presented a correlation coefficient of 0.99. Accuracy was confirmed by analysis of Certified Reference Materials with recoveries of 93-110% and relative standard deviation lower than 6%. Under optimized conditions, a procedural detection limit of 0.28 μg kg^-1 was obtained. Determination of THg in 10 samples of cat food purchased in local markets revealed a concentration range of 0.035-0.388 mg kg^-1. Highest concentrations were found in cat foods. Only one sample presented a concentration close to the regulatory limit of the European Commission Directive. Assuming the estimated daily food intake (EDI) calculated in a range of 0.0021 to 0.023 mg of THg per day per kg body weight, it is concluded that it remains below that considered lethal for cats. The methodology is efficient, simple, low cost, and fit for purpose.

An Alternative Approach to Evaluate the Quality of Protein-Based Raw Materials for Dry Pet Food

The majority of dry pet food currently on the market is produced using fresh meats (FMs) and especially meat meals (MMs) as the main protein source. The transport and storage conditions of the raw materials, together with thermal and mechanical treatments in the case of MMs, may result in undesirable alterations of food products and their protein content. This study was conducted to analyze the protein component of three different kinds of raw materials used for dry pet food production, i.e., chicken, pork, and salmon. The quantitative analysis of the protein component was determined using the traditional Kjeldahl method and near-infrared (NIR) spectroscopy, and an alternative method, i.e., the Bradford assay, while the qualitative analysis was performed through SDS-PAGE, followed by Coomassie Blue staining. The amino acid (AA) profile was also evaluated by quadrupole time-of-flight liquid chromatography/mass spectrometry (Q-TOF LC/MS). In addition, the digestibility was tested through in vitro gastric and small intestine digestion simulation. Statistical analysis was performed by the Student's t-test, and data are reported as mean ± SEM, n = 10 (p < 0.05). The results showed that the MMs are lower in quality compared to FMs, both in terms of protein bioavailability and digestibility, having a lower soluble protein (SP) content (chicken MM = 8.6 g SP/100 g dry sample; pork MM = 6.2 g SP/100 g dry sample; salmon MM = 7.9 g SP/100 g dry sample) compared to FMs (chicken FM = 14.6 g SP/100 g dry sample; pork FM = 15.1 g SP/100 g dry sample; salmon FM = 13.7 g SP/100 g dry sample). FMs appear, therefore, to be higher-quality ingredients for pet food production. Moreover, the Bradford assay proved to be a quick and simple method to better estimate protein bioavailability in the raw materials used for dry pet food production, thanks to its correlation with the in vitro digestibility.

Ontario Veterinary College First-Year Veterinary Students' Perceptions of Companion Animal Nutrition and Their Own Nutrition: Implications for a Veterinary Nutrition Curriculum

Extant research shows veterinarians face increasing challenges in discussing nutrition with clients despite receiving professional nutrition education in the veterinary medical curriculum. This article's aim is to elicit student veterinarians' baseline nutrition-related perceptions and nutrition information-seeking behaviors at the time of entering veterinary school. Participants were newly enrolled veterinary students at the Ontario Veterinary College (n = 120). Focus group discussions (n = 19) informed the design of an online questionnaire capturing students' demographics and perceptions of their own and their pets' nutrition. Students reported being influenced by individual factors (e.g., time), social networks (e.g., family), and surrounding environment (e.g., cost, contradictory media messages). Overall, 58% of students considered themselves knowledgeable about pet nutrition when commencing veterinary school, with 71% prioritizing their pets' diets as much as their own. Students' confidence in finding pet nutrition information was correlated with perceived accessibility (r = .76, p = .001) and perceived quantity of information available on pet nutrition (r = .83, p = .001), but not quality of information (r = .13, p = .03). In general, students relied on and trusted veterinarians for nutrition advice. However, 94% of students mistrusted pet food companies' motivations. Our data support that students entering veterinary school have their own perceptions on pet nutrition that impact nutrition education, suggesting this as an important consideration in the design and delivery of a veterinary nutrition curriculum. Veterinary medical faculty should be encouraged to discuss baseline nutrition information and address any misconceptions to prepare students for future consultations with clients.

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

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.

Toxic Effect of Aflatoxins in Dogs Fed Contaminated Commercial Dry Feed: A Review

Since its first patent (1897), commercial dry feed (CDF) for dogs has diversified its formulation to meet the nutritional needs of different breeds, age, or special conditions and establish a foundation for integration of these pets into urban lifestyles. The risk of aflatoxicosis in dogs has increased because the ingredients used to formulate CDF have also proliferated, making it difficult to ensure the quality required of each to achieve the safety of the entire CDF. This review contains a description of the fungi and aflatoxins detected in CDF and the ingredients commonly used for their formulation. The mechanisms of action and pathogenic effects of aflatoxins are outlined; as well as the clinical findings, and macroscopic and microscopic lesions found in aflatoxicosis in dogs. In addition, alternatives for diagnosis, treatment, and control of aflatoxins (AF) in CDF are analyzed, such as biomarkers of effect, improvement of blood coagulation, rate of elimination of AF, control of secondary infection, protection of gastric mucosa, reduction of oxidative stress, use of chemo-protectors, sequestrants, grain-free CDF, biocontrol, and maximum permitted limits, are also included.

Risk of Foodborne Illness from Pet Food: Assessing Pet Owners' Knowledge, Behavior, and Risk Perception

Pet food has been identified as a source of pathogenic bacteria, including Salmonella and Escherichia coli. A recent outbreak linked to Salmonella -contaminated pet treats infected over 150 people in the United States. The mechanism by which contaminated pet food leads to human illness has not been explicated. Pet owners' food safety knowledge and their pet food handling practices have not been reported. This study evaluated pet owners' food safety knowledge and pet-food handling practices through an online consumer survey. The survey consists of 62 questions and assesses (1) owners' food safety knowledge and pet-food handling practices; (2) owners' interaction with pets; (3) owners' risk perception related to their own health, their children's health, and their pets' health. The survey was pilot-tested among 59 pet owners before distribution to a national consumer panel, managed by Qualtrics XM. All participants (n=1,040) were dog and/or cat owners in the United States. Almost all pet owners interacted with their pets (93%) and most cuddled, allowed their pets to lick them, and slept with their pets. Less than one-third of pet owners washed their hands with soap after interacting with their pets. Over half (58%) the owners reported washing their hands after feeding their pets. Most pet owners fed their pets dry pet food and dry pet treats. Some fed their pets raw meat or raw animal product (RAP) diets because they believed these diets to be beneficial to their pet's overall health. Many owners (78%) were unaware of pet food recalls or outbreaks associated with foodborne pathogens. Less than 25% considered dry pet foods and treats as a potential source of foodborne pathogens. The findings of this study indicated the need for consumer education about pet food handling. The data collected can assist in developing more accurate risk assessment models and consumer education related to pet food handling.

Contamination of Pet Food with Mycobiota and Fusarium Mycotoxins-Focus on Dogs and Cats

A wide range of pet food types are available on the market; the dominant type is dry food formulated in croquets. One of the most common ingredients of dry food are cereals—vectors of harmful mycotoxins posing the risk to pet health. In this study, 38 cat and dog dry food samples available on the Polish market were investigated. Morphological and molecular methods were applied to identify fungal genera present in pet food. Quantification of ergosterol and Fusarium mycotoxins: Fumonisin B₁, deoxynivalenol, nivalenol, and zearalenone were performed using high performance liquid chromatography. Obtained results indicated five genera of mycotoxigenic fungi: Alternaria sp., Aspergillus sp., Cladosporium sp., Penicillium sp., and Fusarium sp., including Fusarium verticillioides and Fusarium proliferatum. Ergosterol and mycotoxins of interest were detected in both cat and dog food samples in the amounts ranging from 0.31 to 4.05 µg/g for ergosterol and 0.3–30.3, 1.2–618.4, 29.6–299.0, and 12.3–53.0 ng/g for zearalenone, deoxynivalenol, nivalenol, and fumonisin B₁, respectively. The conclusion is the presence of mycotoxins in levels much lower than recommended by EU regulations does not eliminate the risk and caution is advised concerning that long-term daily intake of even small doses of mycotoxins can slowly damage pet’s health.

Is the 'canine surrogacy approach' (CSA) still valid for dogs and humans in market-oriented and subsistence-oriented communities in Brazil?

Based on the assumptions that human food is available for dogs and isotope diet-tissue differences are similar in dogs and humans, the 'canine surrogacy approach' (CSA) has been used to infer patterns of ancient populations. The goal of this study was to test the CSA in urban (Brasília and Piracicaba) and in rural (Ubatuba and Maraã) areas. The hair C and N isotope ratios of modern dogs were compared with those of human fingernails from different regions of Brazil. Our CSA results showed a correlation between dog and human isotopes values: in rural areas δ¹⁵N of humans and dogs was not statistically different; contrarily, in urban centres, δ¹⁵N of humans was approximately 1 ‰ higher (p < 0.01) than δ¹⁵N of dogs; humans had lower δ¹³C values (p < 0.01) than dogs in Brasília, Piracicaba and Ubatuba. In Maraã, there was not any significant difference between dogs and humans. We concluded that CSA is still valid as a first approach in modern societies. However, isotopic differences found suggest that in modern societies processed dog food is increasingly disconnecting human and dog, jeopardising the use of CSA in the future if the trend of increasing processed dog food consumption continues to occur.

Food Preferences in Dogs: Effect of Dietary Composition and Intrinsic Variables on Diet Selection

Simple Summary

Preference tests allow the study of some aspects of the feeding behavior of domestic dogs. However, besides sensorial proprieties of food, intrinsic characteristics of dogs may play a role in diet selection. The aim of this study was to describe the feeding behavior of dogs in relation to diet composition and their intrinsic variables (age, breed, sex, and body weight) by using a ten-year database of two-feeder food preference tests (2007–2017). The content of less digestible fractions like crude fiber and dry matter negatively affected dogs’ food preferences. In addition, animals’ weight and breed influenced dogs’ intake of the most preferred diets, where heaviest dogs presented lower intakes as did the Beagle breed in relation with both Boxer and Labrador Retrievers. Moreover, the hot season of the year decreased dogs’ intake of preferred diets. In terms of preferences, Boxers presented a lower preference for selected diets compared to the other breeds. Finally, age and sex did not affect dogs’ preference or intake of the foods selected. The understanding of the relationships between food composition and intrinsic variables of dogs with their diet selection could improve specific pet food formulation in order to satisfy animals’ physiological and hedonic needs.

Abstract

A ten-year food preference database (2007–2017) was used to relate food selection in dogs to the nutritional components of diets by doing a principal component analysis (PCA) and a linear regression between components obtained and dogs’ preferences. Intake and preference of preferred diets were analyzed by dogs’ sex, breed, age, body weight, and the season of the year (hot or cold). The fourth component after PCA presented a relation with food preferences (OR = −2.699, p = 0.026), showing negative correlations with crude fiber (rho = −0.196; P = 0.038) and dry matter (rho = −0.184; p = 0.049). Weight (OR = −1.35; p < 0.001), breed, both Boxer (OR = 10.62; p = 0.003) and Labrador Retriever (OR = 26.30; p < 0.001), and season (hot season) (OR = −5.27; p < 0.001) all influenced animals’ intake. Boxers presented a lower food preference compared to the other breeds (OR = −44.3; p < 0.001), while animals’ weight influenced preferences only in Boxers (OR = 2.02; p < 0.001). Finally, age and sex did not affect dogs’ preference or intake of preferred diets. Thus dry matter and fiber content have a negative impact on dogs’ food choices. Dogs’ weight, breed, and season affected food intake, but only breed affected dogs’ preferences, which is probably explained by adaptive changes in the detection, metabolization, and learning of nutritive food cues.

Carbon and nitrogen isotopic composition of commercial dog food in Brazil

BACKGROUND

Brazil is a low- to medium-income country and has the second largest pet food market in the world with 8% of world pet food consumption. The lowest-income social class spends around 17% of their domestic budget on pet food and other items related to pets. Consumers are frequently misled by advertising as there is no precise information about the main sources of protein, carbohydrates and fat in the labels, and the Brazilian pet food industry can legally claim that their products contain certain items like salmon or beef even if they use just a flavoring compound.

METHODS

The stable isotope methodology compares the stable isotope ratios of carbon (13C/12C) and nitrogen (15N/14N) between source and product. The 13C/12C ratio of a specific product (e.g., dog food) reveals the proportions of C4 (maize) and C3 (soybean, rice and wheat) plants in that product and the 15N/14N ratio reveals the proportion of the compounds derived from animals. With this isotopic data, we used MixSIAR, a Bayesian stable isotope-mixing model, to estimate the proportion of maize, grains, poultry and beef in dog food.

RESULTS

The δ13C values of dry dog food ranged from -24.2‰ to -12.8‰, with an average (± standard-deviation) of -17.1‰ ± 2.8‰. The δ13C values of wet pet food ranged from -25.4‰ to -16.9‰, with an average (± standard-deviation) of -21.2‰ ± 2.4‰, which was significantly lower (p < 0.01). The δ15N values of the dry and wet food ranged from 1.7‰ to 4.2‰, and from 0.5‰ to 5.5‰, respectively. The average δ15N values of dry food (2.9‰ ± 0.5‰) was not higher than the wet food (2.6‰ ± 1.3‰) (p > 0.01). The output of the MixSIAR showed a low proportion of bovine products in dry dog food samples. On the other hand, poultry was obviously the dominant ingredient present in most of the samples. Maize was the second dominant ingredient. Wet and dry dog food showed similar isotopic analysis results. The only difference was a lower proportion of maize and higher proportion of grains in wet dog food.

DISCUSSION

The main finding is that dog food in Brazil is mostly made of approximately 60% (ranging from 32% to 86%) animal-based and 40% (ranging from 14% to 67%) plant-based products. Poultry and maize are the main ingredients. Poultry is added as a by-product or meal, which avoids competition between dogs and humans for meat products, while they can compete for maize. On the other hand, a large proportion of plant-based products in dog food decreases the energy and environmental footprint, since plant-based food products tend to be less harmful compared to animal-based products. Labels can mislead consumers by showing pictures of items that are not necessarily part of the product composition and by not showing the detailed information on the proportion of each ingredient. This information would allow customers to make their own choices considering their pet's nutrition, the competition between animals and humans for resources and environmental sustainability.

Current knowledge of vitamin D in dogs

There is emerging interest in linking vitamin D status to physiological health and disease states in the dog, as evidenced by the recent increase in publications in this area. This research has most likely been spurred by the studies exploring vitamin D and disease in humans. However, there are important differences in vitamin D intake and metabolism between humans and dogs that should be accounted for. The understanding of basic vitamin D metabolism and the relationship between vitamin D intake and vitamin D status in dogs remains even more limited than current knowledge in humans. This review will summarize current knowledge of vitamin D in the dog, including metabolism and dietary recommendations. Emphasis is placed on the limitations to current knowledge. Studies investigating links between vitamin D and disease will be discussed in light of this knowledge. Suggestions for future research, including the development of reference ranges to define blood vitamin D sufficiency, are provided.

Modeling the long-term kinetics of Salmonella survival on dry pet food

Due to multiple outbreaks and large-scale product recalls, Salmonella has emerged as a priority pathogen in dry pet food and treats. However, little data are available to quantify risks posed by these classes of products to both pets and their owners. Specifically, the kinetics of Salmonella survival on complex pet food matrices are not available. This study measured the long-term kinetics of Salmonella survival on a dry pet food under storage conditions commonly encountered during production, retail, and in households (aw < 0.60, 23 °C). A Salmonella enterica cocktail of 12 strains isolated from dry pet foods and treats was used to inoculate commercial dry dog food. Salmonella was enumerated on non-selective (BHI) and selective (XLD and BS) media. Results at 570 days indicated an initial relatively rapid decline (up to 54 days), followed by a much slower extended decline phase. The Weibull model provided a satisfactory fit for time series of Log-transformed Salmonella counts from all three media (δ: mean 4.65 day/Log (CFU/g); p: mean 0.364 on BHI). This study provides a survival model that can be applied in quantitative risk assessment models.

An investigation of selected chemical contaminants in commercial pet foods in Egypt

Our study aimed to identify the levels of various contaminants in both wet and dry commercial pet foods in Egypt. A total of 20 local and imported pet food products (3 samples each) were screened for heavy metals by atomic absorption spectroscopy, for mycotoxins by enzyme-linked immunosorbent assay, and for nitrate and nitrite levels by nitrate-nitrite spectrophotometry. Cat food, on average, had greater concentrations of the metals cadmium, chromium, lead, and tin than dog food. Of the investigated metals, only tin concentration exceeded the safe level compared with the standards of the National Research Council and the European Commission for the dog and cat. According to the guidelines of the Association of American Feed Control Officials for canned pet foods, the nitrate and nitrite contents of examined foods greatly exceeded the recommended level. No total aflatoxins were detected in the surveyed samples. None of the samples analyzed had levels above international limits established by the Food and Agriculture Organization (FAO) of the United Nations for ochratoxin, and only 1 sample exceeded the level for aflatoxin B1. Of the 20 samples analyzed for zearalenone, 4 samples had higher levels than the FAO maximum tolerable levels. These results indicate that pet foods marketed in Egypt, especially cat foods, occasionally contain contaminants that could result in adverse effects in pets.

Evaluation of eight commercial dog diets

Estimation of the quality of commercial diets is a topic of interest for the majority of dog owners. Recently, in a French consumer association magazine, an evaluation of eight dog commercial dry diets (from super-premium, basic-nutrition, private-label and economy brands) according to several nutritional criteria was published. The aims of the study were: (1) to evaluate the apparent digestibility of these diets; (2) to score these diets according to digestibility results; and (3) to compare these data with the scoring of the magazine. Six adult Beagle dogs were enrolled for the digestibility trials. Diets were scored according to energy, crude protein and crude fat (CF) apparent digestibility coefficients, digestible protein-to-energy ratios and ash content. Each of the five criteria was scored from 4 to 20 points. The ranges of crude protein, CF, crude fibre and ash content were 20·9-30·6 %, 6·8-19·7 %, 2·2-3·3 % and 4·6-9·7 % on a DM basis, respectively. The ranges of energy, crude protein and CF apparent digestibility coefficients were 72·6-87·7 %, 70·4-82·5 % and 76·1-95·4 %, respectively. The range of the protein-to-energy ratio was 10-14 digestible crude protein per MJ metabolisable energy. Little overlap in the scoring systems was found, but the private-label brand and economy brand diets presented the lowest scores in the two systems. These results showed that the evaluation of commercial diets should take into account multiple nutritional aspects. In particular, analytical and biological (digestibility) criteria should be considered as complementary in the evaluation of dry dog commercial diets.

Multivariate optimization of an analytical method for the analysis of dog and cat foods by ICP OES

Experimental design methodology was used to optimize an analytical method for determination of the mineral element composition (Al, Ca, Cd, Cr, Cu, Ba, Fe, K, Mg, Mn, P, S, Sr and Zn) of dog and cat foods. Two-level full factorial design was applied to define the optimal proportions of the reagents used for microwave-assisted sample digestion (2.0 mol L(-1) HNO3 and 6% m/v H2O2). A three-level factorial design for two variables was used to optimize the operational conditions of the inductively coupled plasma optical emission spectrometer, employed for analysis of the extracts. A radiofrequency power of 1.2 kW and a nebulizer argon flow of 1.0 L min(-1) were selected. The limits of quantification (LOQ) were between 0.03 μg g(-1) (Cr, 267.716 nm) and 87 μg g(-1) (Ca, 373.690 nm). The trueness of the optimized method was evaluated by analysis of five certified reference materials (CRMs): wheat flour (NIST 1567a), bovine liver (NIST 1577), peach leaves (NIST 1547), oyster tissue (NIST 1566b), and fish protein (DORM-3). The recovery values obtained for the CRMs were between 80 ± 4% (Cr) and 117 ± 5% (Cd), with relative standard deviations (RSDs) better than 5%, demonstrating that the proposed method offered good trueness and precision. Ten samples of pet food (five each of cat and dog food) were acquired at supermarkets in Aracaju city (Sergipe State, Brazil). Concentrations in the dog food ranged between 7.1 mg kg(-1) (Ba) and 2.7 g kg(-1) (Ca), while for cat food the values were between 3.7 mg kg(-1) (Ba) and 3.0 g kg(-1) (Ca). The concentrations of Ca, K, Mg, P, Cu, Fe, Mn, and Zn in the food were compared with the guidelines of the United States' Association of American Feed Control Officials (AAFCO) and the Brazilian Ministry of Agriculture, Livestock, and Food Supply (Ministério da Agricultura, Pecuária e Abastecimento-MAPA).

Elemental composition of dog foods using nitric acid and simulated gastric digestions

Eighteen dry dog foods obtained commercially in the United States were digested using microwave assisted nitric acid digestion and a simulated gastric digestion. Digests were analysed for 23 elements using inductively coupled plasma-mass spectrometry. Data, expressed as dry matter concentrations, were compared to published nitric acid digestion results. Nitric acid data obtained in the present study were not statistically different from published data, with the exception of Mo, Sn, Sb, Tl and Th. However, significant differences in individual intra-sample results were observed between published studies and the present work. Simulated gastric digestions demonstrated lower extraction efficiencies (<50% nitric acid digestions) that were statistically significant. Much lower bioavailability was observed for Al, Ba and Pb. In general, elemental concentrations were determined to be lower than the appropriate Mineral Tolerance Limit or consistent with background concentrations in foodstuffs. Evaluation against Reference Doses (RfDs) showed concentrations for many elements obtained by nitric acid digestion to be above RfD levels. However, the respective simulated gastric digestion data were below or only moderately elevated above RfDs. Only arsenic displayed median and maximum concentrations at factors of five and ten above the relevant RfD.