Table 3.

Summary of in vivo and in vitro studies that have used insects in dog and cat feed.

Authors	Insects	Insect Processing	Conclusions
Bosch et al. [46]	HP, AHC, ML, LML, MWL, BSFL, BSFP, SSR, DHC, AC	Meal from lyophilized insects	In vitro study: the insects had good protein quality indices (high digestibility). Other aspects, such as product safety and pet owner perception are important for the use of insects as an alternative protein source in dog and cat feed.
Bosch et al. [21]	BSFL, HP, ML	Freeze-dried	In vitro study: the protein quality of the insects was high, and the undigested fractions were partially fermented by the microbiota of dogs. Mealworm larvae were the most fermentable.
Böhm et al. [33]	ML	Meal	In vivo study: insect protein-based diet is an interesting alternative for dogs with food allergies.
Kierończyk et al. [85]	ML, ATC, BSFL, ATHC	Air-dried	In vivo study: the smell that emanated from various species of insects was attractive to dogs and could even be a future replacement for flavoring agents.
Paßlack and Zentek [86]	BSFL	Meal	In vivo study: diets based on BSFL were well tolerated and accepted by most cats. The apparent digestibility of the crude protein and amino acids was moderate. It is recommended that an adequate safety margin be considered when formulating insect protein-based diets for cats to prevent nutrient deficiencies.
Jarett et al. [22]	ATHC	Meal	In vivo study: diets containing cricket generate a diversity of microorganisms in the gut microbiota, similar to a healthy balanced diet. These results indicate that crickets could become a nutritious and healthy ingredient for dogs.
Lei et al. [23]	BSFL	Defatted meal	In vivo study: supplementing the diet with BSFL may be beneficial to the nutrition and health of beagle dogs due to its high protein quality and anti-inflammatory and antioxidant capacity.
Feng et al. [87]	ML	Hydrolyzed larvae	In vivo study: mealworm showed lower palatability as dog food compared to hydrolyzed chicken liver but could be improved by the addition of key palatable volatile compounds.
Hong et al. [81]	HM	Meal	In vivo study: HM could be used as an alternative protein source in growing dogs without adverse effects. In addition, its use could reduce oxidative damage in growing dogs.
Hu et al. [88]	SC, MC, MWL	Meal	In vivo study: the insect meals tested had no negative effects on macronutrient digestibility, fecal characteristics and metabolites, or overall health of adult cats.
Kazimierska et al. [56]	BSFL	Meal	In vitro study: dog foods with insect protein exceeded the legal limit for manganese content.
Kilburn et al. [89]	ATHC	Meal	In vivo study: cricket is a highly acceptable ingredient for inclusion in the diet of dogs.
Kröger et al. [39]	BSFL	Meal	In vivo study: BSFL-based feed was well tolerated by dogs. This would indicate that it can be considered as an alternative protein source for dog nutrition.
Freel et al. [90]	BSFL	Meal and fat	In vivo study: food ingredients based on BSFL are well tolerated by dogs and their consumption has no negative physiological impact and could be safely included in dog diets.
Penazzi et al. [91]	BSFL	Meal	In vivo and in vitro study: digestibility analysis of BSFL-based food as sole source of protein showed promising results because it presented similar values as a meat-based diet.

Abbreviations: AC: Argentinian cockroach (Blaptica dubia); AHC: adult house cricket (Acheta domesticus); ATC: adult Turkestan cockroach (Shelfordella lateralis); ATHC: adult tropical house cricket (Gryllodes sigillatus); BSFL: black soldier fly larvae (Hermetia illucens); BSFP: black soldier fly pupae (Hermetia illucens); DHC: death’s head cockroach (Blaberus craniifer); HM: housefly maggot (Musca domestica); HP: housefly pupae (Musca domestica); LML: lesser mealworm larvae (Alphitobius diaperinus); MC: Madagascar hissing cockroach (Gromphadorhina portentosa); ML: mealworm larvae (Tenebrio molitor); MWL: Morio worm larvae (Zophobas morio); SC: speckled cockroach (Nauphoeta cinerea); SSR: six spot roach (Eublaberus distanti).