Can Dogs Eat Seaweed?

A beautiful coastal landscape at sunset, with the sun low in the sky casting a warm glow over the scene. The foreground features tide pools and rocks covered in various types of seaweed, including green and brown algae. The reflection of the sun on the water's surface adds a serene ambiance to the picturesque setting.

What Exactly is Seaweed? 

Seaweeds – or macroalgae – are similar to plants and can be found abundantly in coastal areas, typically attached to rock. They are often referred to as sea-vegetables. Across the world, there are three different seaweed groups that are distinctive in colour; red, green and brown. These seaweed groups will also be distinctive in taste, texture and nutrient profile. As an island nation, Ireland boasts wide variety of red, green and brown seaweeds although the brown varieties are the most abundantly found.

Around the globe, seaweed is eaten in many forms. It is very high in nutrients, a quality that has earned it the nickname “vegetable of the sea”. If you have ever chowed down on these leafy greens and thought, “seaweed is a human food, but can dogs eat seaweed?”, then good news: they can! However, that is the short answer and there are some key things to bear in mind before letting your dog eat seaweed.

The fact that dogs can eat seaweed, does raise a lot more questions. This article will help to answer some of those questions. We will explain exactly what is safe and what is off limits when it comes to seaweed. Can dogs eat seaweed on the beach? Can dogs eat roasted seaweed snacks? We will answer all of this and more. Keep reading to ensure your dog can try out new foods while staying safe, happy, and healthy. 

The nutritional benefits of seaweed

Seaweed is a favourite snack of healthy eaters all around the world, and for good reason! As noted in the Nutritional Value of Edible Seaweeds, the plant is high in essential vitamins and minerals. The key nutritional benefits of seaweed are considered to be the following, but the real benefits of seaweed lie in the polysaccharides, polyphenols, pigments, fibre and polyunsaturated fatty acids:
  1. Calcium: Calcium is essential in maintaining good bone growth, muscle contractions ,and blood coagulation in dogs. According to the Association of American Feed Control, the recommended calcium intake for adult dogs is 50mg per kilogram of body weight. For example, a 10lb dog will require roughly 225mg of calcium per day. Seaweed can contain up to 575mg of calcium per 100g, making it higher in the mineral than most whole foods.
  2. Copper: Seaweed contains a high level of copper, which is important in supporting the skeletal system, protecting nerves, and preventing anaemia. The Association of American Feed Control Officials (AAFCO) suggests a serving of between 3.3mg and250mg per lb of dog food.
  3. Magnesium: This mineral is needed for hundreds of biochemical reactions in your dog’s body. It is especially necessary for maintaining normal nerve and muscle function, supporting the immune system, and regulating the heartbeat. In 100g of seaweed, there can be up to 500mg of magnesium. It is recommended that dogs take150mg of magnesium each day, so seaweed is a great source to meet your dog’s dietary requirements.
  4. ​Iodine: Iodine is an important mineral to include in your dog’s diet as it supports their metabolism and helps to balance their thyroid hormones. It should be noted here that if your dog has hyperthyroidism then feeding Iodine is not something that should be done. The Nutritional Research Council recommends an intake of 220mg of iodine for every 1000 calories a dog eats. As a reference, 10g of dried nori contains up to 232mg of iodine, so a small serving will provide the recommended daily intake of iodine. Iodine can however cause issues for dogs that are undergoing treatment for hyperthyroidism, so these dogs should not consume seaweed based products.
  5. Fiber: some seaweeds also contain high levels of natural, gluten free, fiber. This can be very beneficial for dogs suffering from symptoms like diarrhoea, constipation or anal gland issues. High levels of fiber can help to form healthier stools in the dog's bowel, which can alleviate many of these common health issues suffered by dogs.
  6. Vitamin B12: some seaweeds are also high in vitamin B12, making it one of the few vegetables to provide this nutrient. B12 is necessary in supporting your dog’s nervous system and brain function. It also helps to regulate intestinal health and the growth of blood cells.

The nutrient profiles of seaweed can differ between each variety and also depending on the season, the temperature of the water, tidal flows and other environmental factors. Just as each colour of seaweed can be found in various locations, they each boast different nutritional values and properties.

Red seaweed

Vivid red seaweed illuminated by sunlight, with the light creating a translucent effect on the delicate, leaf-like structures. The seaweed is set against a darker underwater backdrop, with subtle hints of yellow seaweed and the glint of water particles in the surrounding environment.

Some of the macroalgae in the sea-plant kingdom is a striking shade of red. This family of seaweed is high in vitamins, minerals, and antioxidants that can boost a dog's immune system. The red hue of these algae is due to the presence of phycoerythrin and phycocyanin pigments, which obscure other pigments such as Chlorophyll a (not Chlorophyll b), beta-carotene, and specific xanthophylls. The pigments found in these algae, such as phycoerythrin and phycocyanin, have numerous health benefits. They have strong antioxidant properties and can help to reduce inflammation in the body. Additionally, they are believed to boost the immune system and improve heart health. The unique xanthophylls present in these algae have also been shown to support eye health and improve vision. These pigments are becoming increasingly popular as a dietary supplement due to their wide range of health benefits.

Red seaweed such, as the Palmaria palmata (Dulse), which grows on Irish shores, are great for promoting healthy blood circulation, regulating blood sugar levels, boost the immune system, assist with digestion. The calcium and magnesium found in red seaweed also contributes to bone health. Another red variety is Carrageenan, also known as Irish Moss. It is rich in proteins, amino acids, potassium, as well as nutrients such as iron, iodine, and magnesium. Irish Moss can be used to treat health problems such as bronchial issues and urinary infections. It is also a good food to include in your dog’s diet to maintain good health and prevent illness. A natural anti-inflammatory, it helps support the prostate, thyroid, and respiratory tract. There is estimated to be over 6500 red seaweed species worlwide, though this number is constantly been added to.

Green seaweed

Underwater view of vibrant green Ulva lactuca, commonly known as sea lettuce, thriving in its natural marine habitat. The bright green, leafy fronds are illuminated by sunlight filtering through the water, highlighting the plant's delicate textures and shapes.

The green color of these algae is derived from chlorophyll a and b in similar ratios as higher plants; beta-carotene, a yellow pigment; and various distinct xanthophylls, which are yellowish or brownish pigments. There is a family of green seaweeds known as Ulva, for example Ulva lactuca (commonly known as Sea Lettuce) which have a very bright green colour and quite a distinctive, strong flavour. These seaweeds grow commonly around the coastlines of Ireland and many other countries. There are also many other varieties of green seaweed that can be found in locations all over the world, Nori would be one well known green seaweed used commonly in Japanese cuisine. Many varieties within the green seaweed family have high levels of dietary fiber, antioxidants, vitamins and minerals, so can provide a whole host of health benefits for your dog.

Brown seaweed

Close-up of dense, wet brown seaweed (Fucus serratus) with numerous yellow, pod-like structures attached to the fronds, clustered along the rocky shoreline, indicative of a marine environment rich in aquatic plant life.

The brown hue of these algae is attributed to the predominant xanthophyll pigment, fucoxanthin. This pigment covers the presence of other pigments, such as Chlorophyll a and c (there is no Chlorophyll b), beta-carotene, and additional xanthophylls. These pigments found in brown algae, particularly fucoxanthin, have numerous health benefits. Research has shown that fucoxanthin can help to regulate metabolism and improve insulin sensitivity. It is also believed to have anti-inflammatory properties and may help to reduce the risk of chronic diseases such as heart disease and cancer. Fucoxanthin has also been shown to have potential benefits for weight management, protecting the brown adipose tissue whilst encouraging the usage of the white adipose tissue. These pigments, and the extract Fucoidan, are becoming increasingly popular as dietary supplements due to their numerous health benefits. This family of seaweed has the least amount of species, there are about 2000 species, but possibly has the largest amount of biomass, and has many variations. Some of the more well known varieties of brown seaweeds are kombu, kelp, and wakame. It would take many pages to list all of the brown seaweed varieties available in the world but in terms of nutrients, these seaweeds are generally an excellent source of vitamins and minerals, including iodine, iron, calcium, and potassium. They are also known to have anti-inflammatory and antioxidant properties.

Can my dog eat seaweed?

A wet, light-colored dog, possibly a Labrador Retriever, is on a rocky shoreline carrying a piece of seaweed in its mouth. The scene captures the dog in mid-stride, with the ocean horizon in the background and the rocky beach covered in sunlit seaweed.

So with all of this information about seaweed, can dogs eat it? Yes, dogs can eat commercially produced seaweed snacks and supplements, which can allow them to benefit from the plant’s many nutritional advantages. Kelp seaweed varieties (which are generally part of the family of brown seaweeds) are well known and have been identified as a good choice of snack or supplement for dogs, as noticed by animal nutritionists as far back as the 1990s:

“Kelp, in general, is a great addition to the diet. It’s a fairly high-protein plant and has a lot of amino acids. There’s a lot of great nutrition in kelp”

Holistic veterinarian Ruth Roberts

Seaweed for dogs can come as dried powder that is sprinkled onto the food, or even in tablet or treat form. This type of seaweed will have been thoroughly tested and confirmed as safe for human and canine consumption. You should opt for these seaweed products rather than wild seaweed that washes up on the shore. You need to be careful with your dog on the beach to ensure that they don’t eat seaweed that is rotten or contaminated. Therefore, dogs shouldn’t just wander on to the beach and feast on wild seaweed that often wash up on beaches during the summer season. This type of seaweed can hold certain dangers for your dog. The sun can decay wild seaweed quite quickly which can make it rot, this rotten seaweed may contain pathogens or bacteria which may not be good for your dog. There is also the danger of contamination with fishing tackle and other debris from the sea that could harm your dog. 

As with all new foods and supplements that you introduce into your dog’s diet, moderation is key. You should moderate your dog’s intake of seaweed snacks to start with as too much too soon, might cause digestive issues.

What conditions can seaweed supplements target in your dog?

One of the surprising benefits of certain seaweed varieties is that they can support good dental health. It is well known and research that certain brown seaweeds can help decrease the amount of tartar and plaque that forms on dogs’ teeth. This is due to the antimicrobial properties of certain varieties of seaweeds. Strong and healthy teeth equal better breath, a reduced chance of organ disease, and overall wellness in your dog. Incorporating dental seaweed supplements into your dog’s diet can also help you to avoid expensive vet bills!

Seaweed can also help with dogs with skin and coat health as it can help restore dryness to keep your pooch’s skin and coat smooth and supple. It can also support skin pigment issues in dogs that have low thyroid function. Some seaweed varieties, such as Ascophyllum nodosum and the Fucaceae family, contain fucoxanthin which has been found to have strong antioxidant and anti-inflammatory capacities. Some studies have demonstrated the potential health benefits of fucoxanthin in the prevention of major disease, such as cancer, obesity, diabetes mellitus, and liver disease.

Whichever seaweed you choose, make sure to only feed in moderation – and in line with veterinary advice

A lineup of seven seaweed based pet care products on a reflective white surface. From left to right: 'AC4', a green-labeled container with a dog image; 'CANIDENT', with a blue and white label showing a smiling dog; 'Irish Kelp for Pets', in blue with a picture of a dog and cat; 'OCULUS PRIME', in purple, featuring an image of a dog's eye; 'BIOFUNCTION8', in pink, with various pet images; 'KANEX', in green, showing a dog's digestive system; and two spray bottles labeled 'DeNeem' and 'De.Flea Naturally', both with images of dogs and claims of natural ingredients for flea control.

Can dogs eat dried seaweed?

Commercially produced dried seaweed and seaweed powder is safe for dogs if it does not contain salt or any other additives.

Can dogs eat roasted seaweed?

Yes, dogs can eat roasted seaweed! Make sure that the seaweed is not roasted with salt, garlic, onion, or any spices.

Can dogs eat seaweed chips?

Yes, seaweed chips are safe in moderation. The key to identifying suitable seaweed foods for your dog is ensuring they are not covered in salts and spices.

Can dogs eat seaweed snacks?

Yes – as long as they are unsalted. Check the packaging carefully to make sure that the snacks do not contain added salt or other chemicals or additives.

Can dogs eat seaweed that gets washed up on the beach?

Seaweed that has washed up on the beach may be rotten and contain contaminants that could be dangerous to dogs. There may also be a high amount of salt that fresh seaweed absorbs from the sea water.

Can dogs eat salted seaweed?

No – salted seaweed is not safe for dogs. Seaweed already has a salty taste so it tastes delicious without added salt.