The Potential of Microalgae in Pet Food

In the pet food market, interest is growing in novel ingredients that can deliver both high nutritional value and clear product differentiation. Among these, microalgae are attracting attention as a next-generation ingredient capable of supplying a wide range of functional compounds, including omega-3 fatty acids (DHA/EPA), high-quality protein containing all essential amino acids, and powerful antioxidants.

Spirulina in particular is known as a “complete protein,” with 55-70% of its dry weight consisting of protein and a full spectrum of essential amino acids. It also offers excellent digestibility and safety. In addition, microalgae can be cultivated rapidly and at scale, making them a sustainable source of nutrition that does not depend on fish oil or animal by-products, thereby helping to reduce environmental impact.

This article explores the significance and potential of microalgae in pet food development, focusing on their nutritional value, functionality, sustainability, comparative advantages over other ingredients, and examples of adoption in overseas markets.

What Are Microalgae?

Microalgae are a collective term for microscopic algae, including eukaryotic algae such as chlorella, Nannochloropsis, and Haematococcus, as well as cyanobacteria that are often treated as algae, such as spirulina (Arthrospira).

They inhabit a wide range of environments, including seawater, freshwater, and soil, and are characterized by rapid growth rates and the ability to produce diverse metabolites such as long-chain omega-3 fatty acids, functional proteins, pigments, and antioxidants.

Unlike seaweeds such as kelp and wakame, which are visible to the naked eye and classified as macroalgae, microalgae are drawing attention as next-generation ingredients with high flexibility in formulation and functional design.

Representative Types Used in Pet Food

High Nutritional Value and Health Benefits

Microalgae are highly nutritious and contain many beneficial compounds for pet health. Of particular importance are omega-3 fatty acids (EPA/DHA), which contribute to brain function, heart health, and improved skin and coat condition.

Providing adequate omega-3s in pet diets is also a major concern for pet owners. Surveys in Western markets show that as many as 70% of pet owners consider the presence of omega-3s when purchasing pet food.

Dogs and cats cannot synthesize sufficient DHA and EPA on their own and therefore need to obtain them directly from the diet. In this respect, microalgae-derived omega-3s offer quality and effectiveness comparable to fish oil, and studies suggest they help support brain, visual, and cardiovascular health in pets.

Spirulina, one of the best-known microalgae, contains approximately 55-70% protein on a dry-weight basis, an exceptionally high protein content. It also contains all essential amino acids (EAAs) required for maintaining health in humans, dogs, and cats. For this reason, it is regarded nutritionally as a “complete protein.”

Essential amino acids cannot be synthesized by the body and must be obtained from food, making them a critical indicator when evaluating food ingredients. Spirulina contains a well-balanced range of essential amino acids, including leucine, isoleucine, lysine, phenylalanine, threonine, tryptophan, valine, and histidine, which makes it a nutritionally valuable protein source for pet food.

In addition, spirulina protein is highly digestible because its cell wall is thin and contains very little cellulose. This is a major advantage compared with ingredients such as chlorella, which has a thicker and less digestible cell wall. For pets, this means less digestive burden and more efficient amino acid utilization.

Microalgae are also an excellent source of powerful antioxidants. For example, astaxanthin, a red pigment obtained from Haematococcus, is known for its exceptionally strong antioxidant activity and is expected to help regulate immune function and provide anti-inflammatory effects.

Microalgae are also rich in unsaturated fatty acids, vitamins (especially B vitamins), minerals such as iron and calcium, and pigments such as phycocyanin. Their nutritional density is so high that they are often referred to as a “superfood.” Chlorella and spirulina are already widely used in human dietary supplements, with annual production reaching tens of thousands of tons.

By incorporating microalgae-derived compounds into pet food, manufacturers can potentially provide functional benefits such as anti-aging support through antioxidant activity, improved immune health, and better skin and coat condition.

In fact, one study reported that senior dogs receiving algae-derived DHA for six months showed improvements in memory and visual cognition markers, suggesting that scientific evidence supporting the health benefits of microalgae in pets is steadily accumulating.

Sustainability Advantages

One of the greatest reasons to use microalgae is their outstanding sustainability profile. Traditionally, fish oil has been widely used as the main source of omega-3s in pet food. However, around 90% of global fishery resources are already either fully exploited or overfished, raising concerns about the long-term stability of fish oil supply.

Some estimates suggest that the pet food industry uses the equivalent of 930 billion fish annually for fishmeal and fish oil production, making sustainability a major issue. By contrast, producing omega-3s directly from microalgae provides the required nutrients without placing additional pressure on marine resources.

For example, oil produced through fermentation of omega-3-rich marine microorganisms such as Schizochytrium has been reported to replace the equivalent of 66 tons of wild-caught fish per ton of oil produced. In this sense, obtaining omega-3s directly from their original source—algae rather than fish—is a sustainable approach that directly contributes to marine ecosystem protection.

Resource Efficiency

Microalgae significantly improve resource efficiency thanks to their highly sustainable production characteristics. They grow rapidly using sunlight and CO2, and can be cultivated on non-arable land or in saline water, meaning they require very little farmland or freshwater.

They can also be grown in closed systems, making it possible to maintain stable production regardless of weather or season. Land-use efficiency is extremely high; for example, equivalent output can reportedly be achieved using only one-sixteenth of the land required for pea protein. Life cycle assessments (LCAs) have also shown that microalgae can have a lower environmental impact than livestock or conventional crop-derived ingredients.

Reduced Water Use

Microalgae also offer substantial reductions in water use. According to one microalgae startup, producing algae protein requires only one-160th of the water needed for farmed fish production. In addition, saline water and freshwater can be reused, which greatly reduces dependence on freshwater resources.

Short Production Cycles

Microalgae production also compares favorably with conventional plant and animal ingredients. Because algae grow rapidly using sunlight and CO2 and can be cultivated on non-arable land or in saltwater, they require very little agricultural land or freshwater.

As a concrete example, a Canadian microalgae startup uses proprietary fermentation technology to cultivate algal biomass in just seven days and produce high-protein, DHA-containing ingredients. This is dramatically shorter than the seven to nine months typically required to produce plant-based protein crops such as soybeans.

Reduced GHG Emissions

Microalgae can also help reduce greenhouse gas emissions. Algal protein is reported to generate only one-thirtieth of the GHG emissions associated with beef production. When used as a substitute for fish oil, it can also reduce the CO2 emissions associated with the harvesting, processing, and transport of fish. This contributes not only to marine ecosystem protection but also to the reduction of marine-related greenhouse gas emissions.

Advantages Compared with Other Ingredients

Comparison Item	Microalgae	Fish Oil	Animal By-products	Plant Proteins
Nutritional Value	◎ Complete nutritional profile	○ Rich in DHA/EPA	○ High in protein	△ May lack certain amino acids
Stability / Quality	◎ High	△ Prone to oxidation	△ Variable quality	○ Stable
Safety	◎ High	△ Risk of heavy metals	△ Risk of pathogens	○ High
Resource Efficiency	◎ Very high	× Risk of depletion	△ Dependent on livestock	○ Moderate
Environmental Impact	◎ Low	× Fisheries impact	× High	○ Moderate
Functional Benefits	◎ Multifunctional	○ Moderate	△ Limited	△ Limited
Overall Evaluation	◎ Best option	△ Has challenges	△ Has challenges	○ Good

Comparison with Fish Oil

The greatest strength of microalgae-derived oil is that it can match fish oil nutritionally while overcoming many of fish oil’s drawbacks. Fish do not produce DHA or EPA themselves; they obtain them through the food chain. This has led to the idea of bypassing the “middleman” and using algae, the original omega-3 source, directly.

High Concentrations of DHA and EPA

In practice, algae-derived DHA ingredients such as Corbion’s AlgaPrime DHA can contain very high concentrations of DHA and EPA—around 35-60% depending on the product—with some formulations reportedly exceeding the concentration found in standard fish oil products by more than twofold. Using highly concentrated and stable microalgae oil makes it easier to deliver the required amount of omega-3s in pet food with smaller inclusion rates.

Excellent Oxidative Stability and Flavor

Microalgae oil also offers advantages over fish oil in terms of oxidative stability and flavor. It has less of the typical fishy odor associated with fish oil and is reportedly less prone to off-flavors caused by oxidation, making it easier to incorporate into pet food without negatively affecting palatability. It also offers quality advantages such as the absence of heavy metal accumulation risk and the fact that it contains no cholesterol.

Suitable for Vegan and Organic Positioning

From an ingredient-labeling perspective, eliminating fish-derived ingredients also opens up opportunities for vegan and organic product positioning, which can be a key differentiator in the pet food market. In this way, microalgae can be regarded as a next-generation omega-3 source that retains the functional benefits of fish oil while improving safety, flavor, and sustainability.

Comparison with Animal By-products

Animal by-products such as meat meal and organ meats have traditionally been used in pet food as protein and nutrient sources, but microalgae offer several advantages over these materials as well.

High-Quality Protein Source

First, microalgae can serve as a high-quality protein source. As noted earlier, some algae such as spirulina contain high-quality protein with an excellent essential amino acid balance and high digestibility, making them promising alternatives to meat by-products.

Algae-derived ingredients are also clean raw materials that do not carry the same concerns about livestock-derived pathogens or residues of antibiotics and hormones. From a safety and quality-control perspective, cultivated algae also offer advantages such as reduced lot-to-lot variation and better traceability.

Sustainability of Raw Material Procurement

Microalgae also have significance from the standpoint of sustainable sourcing, because they do not rely on by-products from the meat industry. In today’s market, there is growing demand for human-grade pet food and products that avoid by-products. In such high-value categories, algal protein can offer a new solution by reducing reliance on animal ingredients while also lowering environmental impact.

For example, premium vegan pet foods have already appeared in Europe and the United States, and in these products algae are often used to supplement nutrients that may otherwise be lacking, such as DHA and amino acids. Microalgae are therefore likely to become an increasingly important ingredient for developers seeking to complement or replace animal-derived materials while still meeting nutritional requirements.

Comparison with Plant Proteins

Superior Nutritional Value

The use of plant proteins such as soy and peas in pet food has also increased in recent years, but microalgae offer advantages that other plant ingredients do not. One is their nutritional value. Typical plant proteins often fall short in certain essential amino acids, whereas algae-derived proteins generally have a superior amino acid profile. Spirulina, for example, has a very high amino acid score and is considered a complete protein.

Microalgae also contain a wide range of nutrients at the same time, including unsaturated fatty acids, minerals, and vitamins, meaning they function as more than just a protein source. In particular, they can provide nutrients that are difficult to obtain from standard plant ingredients, such as DHA, beta-carotene, and vitamin B12-like compounds.

Production Efficiency and Environmental Impact

A second advantage is production efficiency and environmental performance. As noted above, algae cultivation can produce large amounts of biomass in a very short time and on much smaller land areas than terrestrial crops, while also requiring less water and fertilizer. According to some data, producing one ton of algae protein requires only one-sixteenth of the land needed to produce pea protein, helping conserve limited agricultural land resources.

In addition, algae can be cultivated in dedicated systems independent of conventional farming, making supply more stable and less affected by climate or soil conditions. Plant proteins often experience quality fluctuations due to harvest timing and weather, whereas algae can be produced year-round with more consistent quality. Overall, microalgae combine the benefits of plant proteins—such as sustainability and being free from common animal-related concerns—with superior nutritional value and production efficiency.

Overseas Adoption Cases and Research Trends

The use of microalgae is steadily expanding in overseas pet food markets. In the United States, premium pet food manufacturer Annamaet was among the early adopters of algae and includes sustainable, non-marine DHA sources derived from marine microalgae in products such as Sustain.

The company promotes the concept that since fish obtain omega-3s by eating algae, it makes sense to obtain them directly from algae, the original source. By adding algae-derived DHA, the company aims to support pet brain health as well as skin and coat condition while also contributing to marine resource conservation. The use of algae-derived oil also offers advantages in terms of more stable ingredient supply.

In fact, Veramaris, the joint venture formed by DSM and Evonik, has begun expanding the algae-based EPA/DHA oil it originally developed for aquaculture into the pet food market as well. At Petfood Forum 2024, the company introduced its pet-focused product, Veramaris Pets. This oil contains a combined 60% EPA and DHA, enabling more concentrated and stable supply than conventional fish oil.

According to the company, one ton of its algae oil can replace the use of 66 tons of wild-caught fish, while also helping stabilize raw material supply chains. DSM also offers DHAgold™, a powdered DHA ingredient derived from algae, for which functional evidence has accumulated, including demonstrated cognitive support benefits in dogs.

On the academic side, the number of studies examining the use of microalgae in pets is also growing.

For example, studies using canine gut fermentation models have investigated how the addition of algae such as spirulina (Arthrospira) and chlorella affects the gut microbiota. Although the findings are still limited, some reports suggest changes in short-chain fatty acid production and suppression of certain harmful bacteria, indicating that algae may also have prebiotic potential.

Several animal studies have also focused on anti-inflammatory and immune-enhancing effects, with some reporting reductions in inflammatory markers following continued administration of microalgae extracts. Overseas, governments and research institutions are also supporting the field, with funding from bodies such as the USDA and the EU for research and commercialization projects related to the use of algae in feed.

Thanks to these market and technological developments, microalgae ingredients are now emerging as a highly promising option in pet food development. As commercialization progresses in Europe and North America and rapid growth is expected in the Asia-Pacific region, microalgae are certain to become an important trend in the Japanese pet food industry as well. By combining nutritional and environmental benefits, microalgae truly represent an ingredient for which “what is good for the planet is also good for health.”