The pet care market has been experiencing significant growth in recent years,1 driven by rising pet populations and a growing number of pet owners who view their pets as family members.2 This expanding market fuels the growth of the pet food industry, increasing the demand for high-quality and sustainable pet food options.1 As environmental concerns intensify, interest in alternative protein sources that are nutritious and environmentally friendly grows.3,4 Among these, insect protein has emerged as a promising candidate.5 Studies5–7 have explored the potential of insect protein, highlighting its nutritional benefits and lower environmental influence over traditional animal protein sources.
Research has examined various insect protein types, including black soldier fly larvae (BSFL) (Hermetia illucens), mealworms (Tenebrio molitor), and crickets (Acheta domesticus).6,8,9 These studies6,8,9 show that insect proteins are rich in essential amino acids (AAs), healthy fats, vitamins, and minerals, making them suitable for human and animal foods. The edible insect industry is rapidly evolving, with numerous products, such as insect flours based crackers, breads, cereals, and sauces, being developed for human consumption.10 This trend is also evident in the pet food industry, where insect protein is being incorporated into dog and cat foods.11 The use of insect protein in pet food is driven by its nutritional value and its potential to lower the environmental influence of pet food production.7 A recent global environmental impact assessment revealed that pet food production contributes to greenhouse gas emissions, agricultural land use, and freshwater use, highlighting the need for sustainable alternatives.7,12
Despite the promising attributes of insect-based pet foods, consumer perceptions and acceptance remain mixed.13 Some pet owners worry about the novelty and safety of insect protein, whereas others value its sustainability and its potential as an alternative for dogs allergic to traditional animal-based proteins. A case report demonstrated that a diet containing BSFL meal effectively controlled gastrointestinal symptoms in a dog with a diagnosed food allergy.14 This suggests that insect-based proteins, like BSFL, could offer a promising alternative for dogs with allergies to traditional animal proteins, such as beef or chicken. However, a crossreactivity risk for dogs allergic to mites and shrimps has also been reported,15,16 indicating that caution is needed when considering insect protein as an alternative to specific animal-based proteins.
As interest in sustainable pet food options grows, there is a need for more detailed insights into the nutritional profiles of insect-based dog foods. While previous research has examined certain aspects of insect protein, there is still a lack of in-depth data on the overall nutritional content of commercial insect-based diets. Therefore, this study aims to address this gap by analyzing the nutrient composition of various dog foods formulated with insect protein. The findings from this study will provide important information for pet owners and industry professionals considering the use of insect-based pet food products.
Methods
Sample
Insect-based dog food for all-life-stage or adult dogs, made from insect protein, was purchased from several online stores. We searched for “insect dog food” on a Korean portal and purchased all available products, which came in packages ranging from 0.1 to 3 kg. Foods containing intact animal protein were excluded, whereas those with hydrolyzed animal protein were included due to the limited availability of products containing only insect protein. The purchases occurred in December 2023, and all packages were stored unopened at room temperature until analysis was performed.
Procedures
Proximate analysis
The crude protein (CP) analysis was conducted using the automated Kjeldahl method17 (Kjeltec 8400; FOSS). Approximately 1 g of the ground sample was used. Prior to analysis, each product was thoroughly mixed and then ground using a grinder to ensure sample uniformity. The entire contents of each package were processed, and representative portions were taken for each analysis to avoid bias. Samples were combined with a decomposition catalyst and H2SO4. They were then heated and decomposed in a preheated decomposition unit (Labtec Line Digestion System DT220 Digestor and Labtec Line SR210; FOSS) at 420 °C. The analysis was then automatically performed using a Kjeldahl analyzer. Crude fiber (CFi) analysis was conducted using 0.5 g of ground sample, automatically extracted with a fiber extractor (Fibertec 8000; FOSS). Crude fat (CFa) analysis was conducted using 1 g of ground sample and the acid hydrolysis ether extraction method with an automated fat extractor (Soxtec 8000 and Hydrotec 8000; FOSS). Ash content was determined using 2 g of ground sample, which was burned in an electric furnace at 600 °C for 1 to 2 hours and cooled in a desiccator. Moisture content was analyzed immediately after grinding, using 2 g of the sample, following the oven-drying method as specified in International Organization for Standardization 6496.18
Mineral analysis—For mineral analysis, 0.2 g of the ground sample was dissolved in a hydrochloric acid solution (1:1, v/v) after ashing to prepare the sample solution. The minerals (magnesium, iron, copper, and zinc) were measured using an atomic absorption spectrophotometer (GBC Scientific Equipment; SavantAA). Calcium and phosphorus were analyzed by decomposing the samples with nitric acid using a microwave digestion system (Milestone Ethos Easy; Milestone). The resulting test solution was then injected into an argon plasma. It was then analyzed using inductively coupled plasma optical emission spectrometry (Avio 550 Max; PerkinElmer) to determine calcium and phosphorus concentrations. Quality Control Standard 21 (PerkinElmer Inc) was used as a standard reference.
Stable AA analysis—Acid-stable AAs were analyzed using ion exchange chromatography (Ninhydrin method19). The ground sample (0.1 g) was mixed with 6N-HCl and injected with nitrogen gas, then hydrolyzed at 110 °C for 24 h. After hydrolysis, the solution was transferred to a rotary evaporator flask for evaporation and drying. Subsequently, the hydrolysate was diluted with a sample dilution buffer, filtered, and analyzed using an Amino Acid Analyzer (LA8080; Hitachi High-Tech). A standard reagent (AAS18-10X1ML; Sigma-Aldrich) served as the reference for analysis.
Sulfur-containing AA analysis—The composition of sulfur-containing AAs, such as methionine and cysteine, was analyzed in this study using a method adapted from the Association of Official Agricultural Chemists procedure.20 The analysis was conducted employing ion exchange chromatography with a postcolumn ninhydrin reaction. The performic acid oxidation technique was applied specifically to the sulfur-containing AAs.
Approximately 0.2 g of the ground sample was placed in a decomposition tube with 10 mL of performic acid and incubated overnight in an ice bath. After concentration with a rotary evaporator, 20 mL of 6N HCl was added, and the sample was hydrolyzed at 110 °C for 24 hours under nitrogen gas. The solution was concentrated again and diluted to 50 mL with 0.2 M sodium citrate buffer, then filtered through a 0.20-μm cellulose acetate syringe filter. The analysis was conducted using a Hitachi L-8900 analyzer with an ion exchange column (#2622PH; 4.6 X 60 mm) and PH-SET KANTO buffer as the mobile phase. Detection was performed at 440 nm and 570 nm, with flow rates of 0.30 mL/min for the ninhydrin and 0.35 mL/min for the buffer, and 20-μL sample injections.
Analysis of fatty acid composition—The fatty acid composition was analyzed by extracting approximately 10 g of the ground sample with a chloroform:ether solution at room temperature for 24 hours. The extract was then methylated to prepare the methyl esters. Gas chromatographic analysis of the methyl esters21 was performed using a gas chromatograph equipped with a capillary column, and detection was conducted with a flame ionization detector (HP 6890; Hewlett-Packard).
Nutrient analysis
All nutrient analyses were conducted on a dry matter basis, excluding moisture content. When comparing with the Association of American Feed Control Officials (AAFCO) guideline's recommended nutrient levels,22 the foods intended for all-life-stage dogs were evaluated against both the adult maintenance and growth and reproduction standards. In contrast, foods formulated for adult dogs were only compared with the adult maintenance standards.
Statistical analysis
The Shapiro-Wilk test was used to assess the normality of the data. The Kruskal-Wallis test was used to analyze the differences in nutrition composition between the different types of insects used in the dog foods. Specifically, 3 groups were compared: mealworm-based products, BSFL-based products, and products containing a combination of BSFL and mealworm. The data for the box-and-whisker plots were calculated by determining the median, first quartile, third quartile, and range for each fatty acid concentration in the foods. Results were expressed as median values and ranges, and they were analyzed using SPSS for Windows (version 26; IBM Corp). The graphs were generated using the GraphPad Prism 10 software (GraphPad). Results with P values < .05 were considered statistically significant.
Results
Sample information
Of the 18 dog foods, 12 were manufactured in South Korea, 2 in Germany, 2 in France, 1 in the Netherlands, and 1 in the United Kingdom. Seven of the foods were for adult dogs, and 11 were for all-life-stage dogs. Regarding insect protein sources, 5 products contained mealworms, 3 comprised a combination of mealworms and BSFL, 9 contained only BSFL, and 1 consisted of a mix of oriental flower beetle larvae and mealworms. Fourteen of the foods used only insect protein as the animal protein sources, whereas 4 included insect protein and hydrolyzed animal protein. The fat sources varied and included krill oil, chicken fat, mealworm oil, BSFL oil, salmon oil, sunflower oil, duck oil, fish oil, duck fat, and coconut oil as well as duck fat in various combinations (Supplementary Table S1). Additionally, the diets contained a variety of carbohydrate sources (eg, grains, vegetables), vitamin and mineral supplements, and other additives that could influence the overall nutritional profile of the foods.
Proximate analysis in insect-based foods for dogs
Proximate analysis of 18 insect-based dog foods (Table 1; Supplementary Table S2) revealed that the CP and fat contents met the AAFCO minimum requirements. The AAFCO guidelines do not provide specific recommendations for ash and CFi content. Discrepancies were observed between the labeled and actual contents: 4 foods had CP levels different from those indicated on their labels, and 5 foods had varying CFa levels. For example, 1 product claimed a minimum of 13.0% crude fat, but our analysis showed 10.17%. Another food labeled as containing at least 7.8% crude fat was found to contain 5.6%, whereas a third product labeled with 9.0% crude fat contained 6.23%. Additionally, a product labeled as having 12% crude fat was found to contain 8.93%, a difference of over 25%. In terms of CP, 1 food labeled as having a minimum of 24% was found to contain 22.4%, whereas others labeled as 30% and 31.5% contained 27% and 28.61%, respectively. Furthermore, 1 product labeled with a maximum of 5.0% CFi actually contained 6.39%.
Proximate analysis and mineral content of 18 insect-based dog foods: median, range, and number of foods not meeting Association of American Feed Control Officials (AAFCO) minimum and maximum guideline.
| AAFCO22 | ||||||||
|---|---|---|---|---|---|---|---|---|
| Elements | Median | Range | Growth and reproduction (minimum) | Adult maintenance (minimum) | Maximum | Lower than growth minimum (n = 11)a | Lower than adult minimum (n = 18)a | Higher than maximum (n = 18)a |
| Proximate analysis | ||||||||
| Crude protein (%) | 29.19 | 23.32–38.20 | 22.50 | 18 | ND | 0 | 0 | ND |
| Crude fat (%) | 13.09 | 5.91–26.68 | 8.50 | 5.50 | ND | 0 | 0 | ND |
| Crude ash (%) | 6.95 | 4.73–11.38 | ND | ND | ND | — | — | — |
| Crude fiber (%) | 4.02 | 1.04–6.63 | ND | ND | ND | — | — | — |
| Minerals | ||||||||
| Calcium (%) | 1.30 | 0.91–2.81 | 1.20 | 0.50 | 2.5b | 3 | 0 | 2b |
| Phosphorus (%) | 0.93 | 0.69–1.70 | 1 | 0.40 | 1.60 | 7 | 0 | 0 |
| Magnesium (%) | 0.21 | 0.12–0.31 | 0.06 | 0.06 | 0 | 0 | — | |
| Zinc (mg/kg) | 255.14 | 42.48–511.65 | 100 | 80 | ND | 3 | 3 | — |
| Iron (mg/kg) | 507.85 | 79.80–888.516 | 88 | 40 | ND | 1 | 0 | — |
| Copper (mg/kg) | 18.96 | 6.41–29.75 | 12.4 | 7.3 | ND | 3 | 1 | — |
| Ca:P ratio | 1.59:1 | 0.58–2.95:1 | 1:1 | 1:1 | 2:1 | 2 | 2 | 4 |
Ca = Calcium. ME = Metabolizable energy. ND = No data. P = Phosphorus.
Indicates the number of foods with an all-life-stages or adult maintenance claim, not the number of foods with values below the minimum recommended levels.
The general maximum calcium level is 2.5% dried matter, but for puppies of large breeds (those expected to weigh 70 pounds or more as mature lean adults), the maximum is 1.8%. If 1.8% is used as the maximum, the number of foods exceeding this threshold is 7.
All data are shown in dried matter.
Mineral analysis in insect-based foods for dogs
In the analysis of calcium content in all 18 dog foods, all samples met the AAFCO minimum requirement of 0.5% for adult maintenance, whereas 2 samples exceeded the maximum limit of 2.5%. Among 11 all-life-stage dog foods, 8 samples met the growth and reproduction minimum of 1.2%. All 18 samples satisfied the adult maintenance minimum phosphorus content of 0.4%. Four samples among 11 all-life-stage dog foods met the growth and reproduction minimum of 1%, and none exceeded the maximum limit of 1.6%. All 18 samples met the AAFCO guidelines for magnesium content. However, 3 samples failed to meet the zinc minimum requirements for growth and reproduction or adult maintenance. While all samples met the adult maintenance minimum for iron content, 1 sample did not meet the growth and reproduction minimum. For copper content, 1 sample among 18 dog foods fell short of the adult maintenance minimum, and 3 samples among 11 all-life-stage dog foods did not meet the growth and reproduction minimum.
In the calcium:phosphorus ratio analysis, 2 dog foods did not meet the minimum requirement of 1:1, with observed ratios of 0.58:1 and 0.6:1. Additionally, 4 foods exceeded the maximum requirement of 2:1, with ratios of 2.37:1, 2.44:1, 2.51:1, and 2.95:1. Table 1 presents the median, range, and AAFCO guideline recommendations for the mineral content and ratios in the 18 dog foods. Supplementary Table S3 provides the individual levels of calcium, phosphorus, magnesium, zinc, iron, and copper for each of the dog foods.
Amino acid analysis in insect-based foods for dogs
The analysis of threonine, valine, isoleucine, leucine, methionine, cystine, lysine, phenylalanine, arginine, and histidine content in the 18 dog foods revealed that all samples met the AAFCO adult maintenance minimum requirements. However, for the growth and reproduction minimum requirements, 3 samples did not meet the threonine standards among 11 all-life-stage dog foods. Table 2 presents the median values, ranges, and AAFCO guideline recommendations for each AA. Supplementary Table S4 provides the individual AA levels for each of the dog foods.
Amino acid concentrations in 18 insect-based dog foods: median, range, and comparison to AAFCO minimum guidelines for growth, reproduction, and adult maintenance.
| AAFCO22 | ||||
|---|---|---|---|---|
| Element | Median (%) | Range (%) | Growth and reproduction (minimum, %) | Adult maintenance (minimum, %) |
| Threonine | 1.097 | 0.90–1.55 | 1.04 | 0.48 |
| Valine | 1.564 | 1.29–2.23 | 0.68 | 0.49 |
| Isoleucine | 1.159 | 0.96–1.61 | 0.71 | 0.38 |
| Leucine | 2.065 | 1.55–2.91 | 1.29 | 0.68 |
| Methionine | 0.599 | 0.39–1.17 | 0.35 | 0.33 |
| Cystine | 0.496 | 0.38–0.62 | ND | ND |
| Methionine-cystine | 1.175 | 0.79–1.75 | 0.7 | 0.65 |
| Lysine | 1.63 | 1.37–2.18 | 0.9 | 0.63 |
| Phenylalanine | 1.23 | 0.95–1.6 | 0.83 | 0.45 |
| Alginine | 1.688 | 1.11–2.30 | 1 | 0.51 |
| Histidine | 0.653 | 0.49–0.95 | 0.44 | 0.19 |
All data are shown in dried matter.
Fatty acid analysis in insect-based foods for dogs
Table 3 shows the median values and ranges for saturated and unsaturated fatty acid content in the 18 insect-based dog foods. Supplementary Tables S5 and S6 provide the individual levels of fatty acids for each of the dog foods. According to AAFCO guidelines, the minimum requirements for linoleic acid and α-linolenic acid were met by all 18 dog foods. However, 3 of the 11 all-life-stage dog foods had eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels below the required 0.05% dry matter (DM). Additionally, the recommended maximum ratio of linoleic + arachidonic acid to α-linolenic + EPA + DHA is 30:1, and 2 of the dog foods exceeded this ratio. Dog food containing BSFL had the highest levels of lauric and myristic acid, followed by food with a combination of BSFL and mealworms. In contrast, foods made solely from mealworms or oriental flower beetle larvae had the lowest levels of these fatty acids (P = .0303 for lauric acid; P = .0024 for myristic acid; Figure 1).
Fatty acid concentrations in 18 insect-based dog foods: content in grams per 100 g fatty acid and percentage of total dry matter (DM).
| Elements | Median (grams per 100 g fatty acid) | Range (grams per 100 g fatty acid) | Median (% DM) | Range (% DM) |
|---|---|---|---|---|
| Saturated fatty acid | ||||
| Caproic acid | 0.075 | 0.04–0.17 | 0.010 | 0.004–0.018 |
| Caprylic acid | 0.045 | 0.03–1.87 | 0.005 | 0.003–0.181 |
| Capric acid | 0.13 | 0.03–1.92 | 0.021 | 0.002–0.186 |
| Lauric acid | 3.675 | 0.08–33.25 | 0.625 | 0.005–4.550 |
| Myristic acid | 1.59 | 0.57–10.72 | 0.236 | 0.051–1.080 |
| Pentadecanoic acid | 0.1 | 0.02–0.25 | 0.016 | 0.002–0.031 |
| Palmitic acid | 17.16 | 9.39–22.77 | 2.087 | 0.790–5.896 |
| Magaric acid | 0.15 | 0.06–0.47 | 0.019 | 0.007–0.058 |
| Stearic acid | 5.03 | 2.82–5.79 | 0.634 | 0.299–1.504 |
| Arachidic acid | 0.03 | 0–0.2 | 0.004 | 0–0.013 |
| Heneicosylic acid | 0.08 | 0.03–1.16 | 0.012 | 0.003–0.191 |
| Behenic acid | 0.165 | 0.03–0.57 | 0.023 | 0.004–0.094 |
| Lignoceric Acid | 0.095 | 0.02–0.58 | 0.014 | 0.002–0.096 |
| Unsaturated fatty acid | ||||
| Myristoleic acid | 0.095 | 0.02–0.23 | 0.014 | 0.002–0.061 |
| Pentadecenoic acid | 0.03 | 0.02–0.11 | 0.003 | 0.002–0.018 |
| Palmitoleic acid | 3.985 | 0.49–6.02 | 0.547 | 0.041–1.561 |
| Magaoleic acid | 0.13 | 0.04–0.43 | 0.018 | 0.004–0.071 |
| Oleic acid | 32.835 | 14.56–41.08 | 4.544 | 1.558–10.959 |
| Linoleic acid | 17.655 | 12.65–48.41 | 2.353 | 1.403–7.518 |
| γ-Linolenic acid | 0.295 | 0.16–0.58 | 0.039 | 0.019–0.071 |
| linolenic acida | 3.02 | 0.68–7.29 | 0.334 | 0.084–0.819 |
| α-Linolenic acidb | 2.66 | 0.28–7.09 | 0.280 | 0.035–0.773 |
| Eicosenoic acid | 0.55 | 0.19–6.01 | 0.073 | 0.014–0.991 |
| Eicosadienoic acid | 0.03 | 0–0.2 | 0.004 | 0–0.033 |
| Dihomo γ-linoleic acid | 0.04 | 0–0.09 | 0.004 | 0–0.016 |
| Eicosatrienoic acid | 0.02 | 0–0.04 | 0.003 | 0–0.006 |
| Aracidonic acid | 0.315 | 0.01–4.54 | 0.046 | 0.001–0.749 |
| EPA | 0.22 | 0.05–3.35 | 0.022 | 0.005–0.552 |
| Erucic acid | 0.215 | 0.06–0.77 | 0.025 | 0.008–0.120 |
| Docosadienoic acid | 0.12 | 0.05–0.47 | 0.013 | 0.005–0.078 |
| Nervoinic acid | 0.055 | 0–0.83 | 0.008 | 0–0.137 |
| DHA | 0.115 | 0.04–2.98 | 0.015 | 0.002–0.491 |
| EPA+DHAc | 0.415 | 0.11–6.33 | 0.040 | 0.009–1.044 |
| Linoleic + arachidonic:α-linolenic + EPA + DHA ratiod | 6.86:1 | 2.02:1–121.05:1 | ||
DHA = Docosahexaenoic acid. EPA = Eicosapentaenoic acid.
According to the AAFCO guideline,22 the minimum requirement of linoleic acid is 1.3% DM for growth and reproduction and 1.1% DM for adult maintenance. All-life-stage dog foods in this study met these requirements.
According to the AAFCO guideline,22 the minimum requirement of α-linolenic acid for growth and reproduction is 0.08% DM, which is met by all-life-stage dog foods in this study.
Box-and-whisker plots of lauric acid (A) and myristic acid (B) concentrations (grams per 100 g fatty acid) for 18 commercially available insect-based foods for dogs evaluated from November 27, 2023, through February 2024 and grouped on the basis of diet protein source: black soldier fly larvae (BSFL), black soldier fly larvae and mealworms (MW), or MW. For each plot, the horizontal line in the box represents the median; the upper and lower limits of the box represent the first and third quartiles, respectively; and the whiskers represent the range. The Kruskal-Wallis test was used to analyze differences between groups. Lauric acid and myristic acid levels were significantly higher in the BSFL foods compared to the MW foods. The MW group includes 1 diet that contains a mixture of mealworms and oriental flower beetles.
Citation: American Journal of Veterinary Research 86, 1; 10.2460/ajvr.24.08.0243
Given the variety of added fats used in these diets, such as krill oil, chicken fat, duck fat, salmon oil, sunflower seed oil, black soldier fly oil, mealworm oil, and coconut oil, analyzing their impact on fatty acid content proved difficult. While 2 foods containing black soldier fly oil showed relatively higher levels of lauric acid and myristic acid, the sample size was too small for statistical significance. Furthermore, conflicting results were observed in the 2 foods containing coconut oil, where 1 had higher myristic acid levels and the other had lower levels. These results suggest that the amount of added fat may play a more significant role than the type of fat used. Overall, the primary insect protein source appeared to have a greater influence on the fatty acid composition than the added fats.
Discussion
This study showed that while all 18 insect-based dog foods met the AAFCO minimum requirements for CP and CFa for adult maintenance and for growth and reproduction, discrepancies were noted between the labeled and actual nutrient contents in several samples. Although these discrepancies do not indicate a failure to meet the minimum nutritional requirements, they do raise concerns about the accuracy of labeling and the potential implications for consumer trust and the precise formulation of foods for specific life stages. Ensuring accurate labeling is crucial for providing pet owners and veterinarians with reliable information, particularly when selecting foods intended for growth, reproduction, or maintenance of specific health conditions.
In analyzing the mineral content of 18 insect protein–based dog foods, we found that except for magnesium, other minerals (calcium, phosphorus, zinc, iron, and copper) were below the AAFCO recommended minimum levels in some samples. Additionally, many of these foods did not meet the recommended calcium-to-phosphorus mineral ratios. Interestingly, discrepancies in calcium, phosphorus, and their ratio were observed only in Korean-made dog foods, whereas the dog foods produced in other countries adhered to the recommended levels and ratios for these minerals. While deviations from the recommended dietary guidelines for calcium and phosphorus levels and their ratio can theoretically contribute to conditions such as hypercalcemia, hypophosphatemia, or skeletal abnormalities,23–26 the extent to which the discrepancies observed in this study would result in such conditions requires further investigation. Though the magnitude of these deviations may not pose an immediate health risk, long-term feeding of diets with these imbalances could potentially lead to health issues over time. Therefore, additional research on the long-term effects of these mineral imbalances is warranted.
In growing puppies, deficiencies in zinc, copper, or iron can lead to stunted growth, dermatologic problem, alopecia, neurologic sign, and anemia.27–29 It is important to note that these dog foods contain various additional ingredients, including mineral and vitamin supplements. The mineral content observed in this study is likely influenced by these added supplements rather than the insect ingredients themselves. However, the exact amounts and forms of added minerals were not specified, making it difficult to assess their impact on the diets’ nutritional adequacy. Furthermore, we did not evaluate the bioavailability of these added minerals, which could significantly affect their nutritional efficacy. Therefore, conclusions about their direct health effects based solely on their content are limited.
Amino acid analysis revealed that while all dog foods met the AAFCO adult maintenance requirements, 3 samples fell short of the growth and reproduction standards for threonine. In growing dogs, deficiencies in methionine and threonine can cause reduced food intake and weight loss.30 This can also increase blood and urinary urea levels due to nitrogen imbalance.30 This underscores the negative effects of threonine deficiencies on growth and metabolism, emphasizing the need to meet recommended intake levels.
The fatty acid analysis revealed that all dog foods met the minimum AAFCO requirements for linoleic acid and α-linolenic acid. However, 3 samples had EPA and DHA levels below the required amount for growth and reproduction, and 2 samples exceeded the recommended maximum ratio of linoleic and arachidonic to α-linolenic acid+EPA + DHA of 30:1, with the ratios reaching 121.05:1 and 121.03:1, respectively. The omega-3 fatty acids measured in this study included α-linolenic acid, EPA, and DHA, which have different physiological impacts. The amounts of EPA and DHA are particularly important as they play a critical role in modulating inflammation and promoting fat oxidation.31 A lower omega-6:omega-3 ratio in dogs is known to reduce inflammatory responses and oxidative stress, as demonstrated by increased prostaglandin E3 production and reduced malondialdehyde levels.32 Additionally, diets with a high omega-6:omega-3 ratios have been associated with increased superoxide production and proinflammatory leukotriene B4 in neutrophils.31,33 In contrast, a lower ratio promotes the production of anti-inflammatory leukotriene B5.33 In humans, a higher dietary omega-6:omega-3 ratio is linked to an increased risk of cardiovascular diseases, cancer, and autoimmune diseases.34,35 An imbalanced fatty acid ratio can cause inflammatory responses and other health issues in dogs, highlighting the need for careful formulation of these ratios in pet foods.
Analysis of the fatty acid profile in insect-based dog foods revealed that these foods are generally rich in unsaturated fatty acids, especially oleic and linoleic acids, and in saturated fatty acids, particularly palmitic acid (Table 3). The levels of lauric and myristic acids varied significantly depending on the type of insect used, with BSFL-based foods having notably higher concentrations compared to mealworm-based foods (Figure 1). Studies36 that examined the composition of edible insects indicate that BSFL have higher levels of saturated fatty acids than other edible insects. The primary fatty acid in BSFL fat is lauric acid, followed by myristic and palmitic acids.37 In addition to the insect ingredients, the added fats in each diet likely contributed to the overall fatty acid profile. For example, fats such as coconut oil and BSFL oil, known for their high lauric and myristic acid content, may have further increased the levels of these fatty acids in certain foods. However, the precise impact of added fats varied based on their type and quantity, making it difficult to isolate their specific effects. Research comparing BSFL oil with other commercial oils also showed that it contains higher levels of lauric and myristic acids.38 Lauric acid has demonstrated antiviral and antibacterial properties in various studies,39–41 including its effectiveness against antibiotic-resistant Propionibacterium acnes, which causes inflammatory acne. Myristic acid has also been shown to promote the proliferation and differentiation of neural stem cells in vitro.42 Additionally, systemic administration of myristic acid improves GABAergic signaling imbalance and alleviates hippocampal neurodegeneration in naturally aged mice with hippocampal degeneration and memory decline.43 While these findings highlight the potential health benefits of incorporating BSFL oil into dog foods, it is important to note that these effects were observed in nondietary contexts, and there is no evidence that similar benefits occur when these fatty acids are consumed as part of a diet.
Despite the strengths of this study, several limitations should be noted. First, the study did not include a control group of traditional dog foods made from animal protein, limiting direct comparisons between insect-based and traditional diets. While previous studies provide useful insights into traditional pet food nutrient profiles, future research should aim for direct comparisons. Second, the study focused on nutrient content but did not assess the bioavailability of the nutrients. Feeding trials or digestibility studies are necessary to determine whether the nutrients present in insect-based diets can meet the nutritional needs of dogs. Third, commercial pet food formulations may change over time due to ingredient availability and cost, meaning the results of this study reflect the products at the time of analysis. Finally, this study primarily focused on protein and fatty acid content, giving less attention to other important components, such as carbohydrates, fibers, and additives, which may also impact the overall nutritional balance and health outcomes.44–48
In conclusion, while insect-based dog foods offer promising protein content and beneficial fatty acid profiles, this study revealed significant discrepancies with AAFCO guidelines, particularly in mineral content. The failure of many Korean-made dog foods to meet calcium and phosphorus recommendations, especially for all life stages, is concerning due to the critical role these minerals play in skeletal health. Although this study provides valuable insights, it did not comprehensively assess all nutrients nor conduct feeding trials. Therefore, further research, including a broader nutrient analysis and feeding trials, is needed to fully evaluate the nutritional adequacy and long-term health effects of insect-based diets. Additionally, stricter regulations and better enforcement are essential to ensure that insect-based dog foods meet the nutritional needs of dogs at all life stages, supporting the development of sustainable and health-conscious pet food options.
Supplementary Materials
Supplementary materials are posted online at the journal website: avmajournals.avma.org.
Acknowledgments
This study was partially supported by the Research Institute for Veterinary Science, Seoul National University.
Disclosures
The authors have nothing to disclose. No AI-assisted technologies were used in the generation of this manuscript.
Funding
The authors have nothing to disclose.
ORCID
M. O. Ryu https://orcid.org/0009-0002-9654-5066
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