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Can Dogs Eat Fish? – Fresh, Raw & Frozen – Risks & Benefits

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Can Dogs Eat Fish?

Many cans of dog food have fish on the menu so yes, dogs can eat fish. But don’t take the bait and think if fish is ok canned then all you need is a boat, rod, and reel, combined with a little luck to save a little money.

The truth is that canned fish has been heavily processed to make it safe for your dog and fresh fish is not.

So if you are thinking about feeding unprocessed, fresh, raw, or frozen fish to your favorite canine friend, you should research deeper into the question… Can Dogs Eat Fish?

In this post, you will learn the risks and benefits of feeding fresh fish to your dog, and whether the fish is best served soft and raw, or frozen.

I will also cover the question of boned or de-boned, and discover which fish dogs can eat happily and those which are best left in the sea.

What are the Risks To Dogs From Eating Raw Fish?

When a dog eats raw fish there are risks involved from parasitic infestations, bacterial growth, mercury poisoning, hypernatremia (too much sodium), and thiamine (vitamin B1) inactivation.

Plus, your dog might be allergic to a certain type of fish and experience a strong allergic reaction.

And there is an ongoing debate about whether fishbones can tear through your dog’s intestine wall, block the gut, and/or pose a choking hazard to dogs.

Or as the raw food feeders argue. Animals including birds, wolves, and bears have been munching on fresh fish and bones for years and unlike humans, have adapted to do so.

However, there are some risks and the main ones are detailed below.

Risk factor 1. – Parasites

Fish often pick up and transmit many parasites which can be found in the skin, muscle tissue, and internal organs of a fish.

Some of which can be potentially fatal for dogs.

Raw salmon has been known to contain a parasite called Neorickettsia helminthoeca, which leads to salmon poisoning in dogs.

However, most fish on fish farms are treated for parasitic invasion. And a well-run freezing regiment will kill the parasites and inhibit bacterial growth during the moving and storing processes of wild-caught fish.

That being said, fresh and frozen fish purchased from an unknown source might not have followed all the freezing and storing guidelines.

The most common parasites found in raw fish are:

  • Flukes – (parasitic flatworms) are known as flukes.
  • Roundworms – (have tubular digestive systems with openings at both ends). 
  • Tapeworms – ( A tapeworm infection can be seriously harmful. Your dog can become unwell, and infected puppies can suffer from anemia, slow growth, and intestinal blockage.
  • Nematodes (parasitic roundworms) cause anisakiasis, also known as herring worm disease.

How can I prevent anisakiasis?

Do not eat raw or undercooked fish or squid. (CDC Guidelines)

The FDA recommends the following for seafood preparation or storage to kill parasites.

  • Cooking (Seafood in General)
    • Cook seafood adequately (to an internal temperature of at least 145° F [~63° C]).
  • Freezing (Fish)
    • At -4°F (-20°C) or below for 7 days (total time), or
    • At -31°F (-35°C) or below until solid, and storing at -31°F (-35°C) or below for 15 hours, or
    • At -31°F (-35°C) or below until solid and storing at -4°F (-20°C) or below for 24 hours.

Risk factor 2. – Bacteria

If the fish was not stored and temperature controlled correctly there is a risk of bacterial organisms such as Salmonella, Listeria, and Clostridium.

This is why it is so important to know the source and history of the fish you are buying.

Risk factor 3. – Mercury poisoning

Some specific species of fish contain high levels of mercury which is toxic and must never be fed to your dog.

A basic rule of thumb is the deeper the fish dives and the bigger the fish the higher the mercury content will be, which usually means the smaller the fish the better.

For example, tuna, and Swordfish are high in mercury whereas anchovies and sardines are not.

Skipjack tuna has the lowest mercury levels in the tuna family.

Signs Of Mercury Poisoning In Dogs Include:

  • Anxiety
  • Loss of coordination
  • Diarrhea
  • Vomiting (may include blood)
  • Urine retention
  • Abdominal swelling
  • Tremors
  • Hair loss
  • Blindness

    If you believe your dog has mercury poisoning you must seek the advice of a veterinarian immediately.

Table Of Fish Safe For Dogs And Those Best Left In The Sea!

The table lists fresh fish in ascending order of mercury levels from lowest to highest. FDA Content current as of 02/25/2022

Mercury Level
Low
Mercury Level
Low
– Medium
Mercury Level
Medium – High
SardineJacksmeltWeakfish – Sea Trout
TilapiaMackeral – Chub – PacificHalibut
AnchoviesWhitefishCroaker White – Pacific
SalmonSheepsheadBass – Chilean
CatfishCarpTuna – Yellowfin
PollockCodTuna – Albacore
ShadPerch – OceanSablefish
Mackeral – N.AtlanticBuffalofishBluefish
MulletSkateGrouper – (All)
WhitingTilefishMackerel – Spanish
Haddock – AtlanticTuna – SkipjackMarlin
FlatfishPerchOrange Roughy
ButterfishMonkfishTuna – Bigeye
Croaker – AtlanticSnapperMackerel – King
Trout – FreshwaterBass – Saltwater, Black, StripedShark
HerringMahi MahiSwordfish
HakeMackerel – SpanishTilefish
Mercury Levels in Commercial Fish and Shellfish (1990-2012) — Content current as of:
02/25/2022

Risk factor 4. – Hypernatremia

Many fish live in salt waters which are absorbed into the skin and meat of the fish making them high in sodium, (salt content).

A buildup of salt in your dog will cause hypernatremia which can lead to health problems for your dog if not addressed.

However, the risk is very small if the diet is varied.

Risk factor 5. – Thiaminase in fish

Thiamine (vitamin B1) is used by the body to break down food and turn it into energy making it a vital component in the body.

Thiaminase is an enzyme that breaks down thiamine which means too much thiaminase in the body is dangerous to health and all fish contain thiaminase at varying concentrations.

Thankfully heat destroys thiaminase but a constant diet of raw fresh fish is dangerous as the thiaminase levels can increase over time. This is why a varied diet is a better diet.

So although dogs can eat fish you must first research the risks, become informed and then balance the benefits before you decide to feed raw fish to your dog.

alsatian dog sleeping on a chair with his favorite lilac ball
slice of raw salmon on ice

If you do not know or are unsure about the source of any type of fish, it should be avoided altogether.

What Are The Benefits To Dogs From Eating Raw Fish?

Fish are a great source of protein, calcium, selenium, niacin, vitamins (especially B vitamins), and EPA and DHA Omega-3 fatty acids for your dog.

EPA and DHA Omega -3 fatty acids can help the heart to maintain a steady rhythm and prevents fat build-up leading to cardiovascular problems. EPA also aids in reducing inflammation while DHA is good for higher brain functions.

Oily fish can be beneficial as this type of fish can be high in Vitamin D which your dog cannot produce but usually sources it from eating whole prey such as rabbits.

The fish of the skin, don’t worry about the scales, is a great source of collagen which is very beneficial for the bone and skin of older dogs.

So as a whole, fresh fish is extremely beneficial for the development and functions of many of the dog’s bodily systems from pup to senior.

But, remember that moderation is the key to a healthy diet, and whilst dogs can and do, benefit from fish, this type of food should only account for a small part of their diet if fed alongside kibble and canned.

The major benefits of feeding your dog Fish are:

  • They are high in Omega-3 fatty acids and essential vitamins and minerals.
  • Fish is a high protein source.
  • Fish is generally low in levels of fat.
  • Fresh fish is an excellent alternative food source for dogs with allergies. 

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Can dogs Eat Fish That Are Fresh Caught And Soft – Not Frozen?

Fish taken straight from the water may contain parasites under the scales of the fish or within the body and the meat which can be dangerous to dogs.

Therefore it is not advisable to feed your dogs these fish until they have been frozen at – 4°F / – 20°C or below for at least 7 days, or at – 31°F / -35°C for 15 hours to kill the parasites.

Fresh unfrozen fish can be fed to a dog if it has been stored and chilled to prevent bacterial growth and has been cooked thoroughly.

Cooked fish will need to be de-boned before feeding to your dog as the cooking process will alter the bones’ composition making them hard, indigestible, and likely to shatter.

Fish that have previously been frozen for three weeks, to kill any parasitic infestation, and are now thawed and soft can be fed to your dog with or without de-boning. This applies to fish purchased from a pet or grocery store,

However, some dogs do not like the fish served soft and would prefer the fish to be frozen as this helps them to hold on to it as makes gnawing it easier.

Veterinarians do not agree with giving a whole fish to a dog with bones included.

But the raw feeding community who regularly feed whole fish to their dogs’ argue that wild animals including birds and cats do not de-bone their prey.

Can A Dog Eat A Soft Fish That Has Not Been Cooked Or De-Boned?

The Raw feeder’s community strongly supports giving the whole fish, with possibly the tail and fins removed, to the dog. This community regularly freezes the fish for 7 days to kill any parasites and then will give the fish to the dog bones and all.

Raw feeders argue that in the wild, all animals catch and eat their prey without de-boning them first or removing the head, etc. so, to them, it is safe.

The counter-argument is from the food manufacturers and the veterinarians who believe that dogs have de-evolved from wolves. This community believes that the sharp fish bones if ingested could rip and tear at a dog’s soft internal organs and cause irreparable damage.

The important word here is could.

On this matter, it is your call, but you must consider that if you are applying for pet insurance; what and how you feed your dog may be a critical factor.

Can dogs Eat Fish That Is Raw And Still Frozen?

If a fish has been caught in the wild it is always best to freeze it for at least 7 days at – 4°F / – 20°C or below, or at – 31°F / -35°C for 15 hours to kill all possible parasitic infestations.

But there is no need to thaw, debone, or gut the fish before feeding it to your dog as most dogs love to chew on whole frozen fish but you might want to remove the fins and tail.

The raw feeders’ community regularly posts videos on youtube showing this whole frozen fish in action but veterinarians argue against it, so ultimately it’s your call.

However, If you intend to thaw and cook the fish it may be safer to de-bone the fish as cooked bones are dangerous to dogs as they tend to splinter and form sharp indigestible shards.

Fish that has been stored, frozen, and sold by a reputable dog food company will have already killed all the parasites before sending the fish to the retailer.

Can Dogs Eat Fish Sticks?

As a small treat, no harm will come to your dog eating a fish stick or two.

However, please note that fish sticks have no nutritional value and can only hydrate your dog at best.

Can Dogs Eat A Red Herring?

A herring can turn red if it spends several weeks in a smoking kiln which dries out the fish and turns it red and wrinkly.

Dogs should never be fed red herrings as the salt i.e. sodium levels are extreme and can give mild to severe short-term stomach irritation or long-term sodium poisoning if fed regularly.

Bet you thought a red herring was just a clue or piece of information which is intended to be misleading or distracting didn’t you?

What Fish Are The Most Common Fish Fed to Dogs?

frozen fish

The most common fish safe for dogs to eat can be found in many brands of commercial dog food.

But these fish may not be the most beneficial to dogs but are probably the cheapest and most abundant fish the manufacturer can buy and be able to make a profit.

In truth, the list of fish safe and beneficial for dogs to eat is large and varied. But if you use the guide of small, oily, short-lived, and low on the food chain, you should be alright.

So let’s get started with the most common fish safe for dogs to eat.

1. Can Dogs Eat Anchovies?

Yes! Anchovies are one of the most nutrient-rich and healthiest fishes you can give to your dog. They are also great for puppies as they are small, soft-boned, easy to chew, and provide little risk of choking.

This makes them perfect as a food source as they are bite-sized, nutrient-rich, and packed full of DHA and EPA Omega-3 fatty acids. In fact, anchovies are one of the most nutrient-rich fish in the sea and offer a wide range of health benefits.

Coming in at just 8 calories each and able to be eaten fresh, raw, frozen, canned, and cooked their small size also makes them ideal as a low-calorie snack or treat.

If you buy them canned make sure they are without added salt spices or oil.

Smaller dogs can safely eat two to three anchovies per day, while larger dogs can eat up to five.

two dogs waiting for treats
3 dogs waiting for treats

2. Can dogs Eat Cod?

Cod is another excellent fish for dogs to eat, and unlike mackerel, most dogs will immediately take to it.

The skin of a cod is a particular favorite for most dogs, but, as with all fish, ensure it has been cooked thoroughly and then de-boned before giving it to little Fido!

Or feed it raw after it has been frozen for 7 days at – 4°F / – 20°C to kill off any potential parasites.

3. Can Dogs Eat Herring? (Not A Red Herring!)

Herring is safe for dogs to eat in either raw or cooked form but must be frozen for 3 weeks at a minimum of – 4°F / – 20°C to kill off a potential parasite called herring worm.

Herring worm disease is a parasitic disease caused by nematodes (worms) that attach to the wall of the esophagus, stomach, or intestine.

Herring worms will cause abdominal pain, sickness vomiting, diarrhea, blood and mucus in stools, and a mild fever. In some cases, a dog can have an allergic reaction with a rash and itching being a secondary marker.

Herrings are a good food source for dogs as they are high in protein, EPA, and DHA Omega-3 and 6 fatty acids, and the vitamins B3, B6, and D.

However, herring is higher in thiaminase so it’s best not to feed herring as a regular part of a dog’s diet and herring should be prepared separately to prevent the thiaminase from tainting other foods.

4. Can Dogs Eat Mackeral?

Mackerel is a fish that is high in EPA and DHA Omega -3 fatty acids and is also rich in Vitamin D but it can be an acquired taste.

For those dogs who will take to it, the acids can help improve skin conditions, reduce allergies and improve the fur.

It can even help to reduce shedding.

When served in moderation and not regularly, Mackeral can be a very beneficial part of your dog’s diet.

5. Can Dogs Eat Salmon?

Salmon is another fish high in EPA and DHA Omega-3 fatty acids as well as vitamin D. and it is better to get wild caught rather than farmed, as farmed fish may contain chemicals, but it is important to find out where it was sourced.

Additionally, resist the temptation to feed your dog smoked salmon as the curing process involves adding lots and lots of salt which is not good for your dog.

And, salmon caught in the pacific northwest should be frozen for 3 weeks at a minimum of – 4°F / – 20°C to kill any potential risk of salmon poisoning.

Raw or undercooked salmon may contain parasites, which are poisonous to dogs.

For small, weak, or older dogs, these parasites cause many health issues which can be severe enough to be life-threatening or often fatal.

The symptoms include severe diarrhea, cramping, vomiting, and dehydration, and in all cases, veterinarian advice must be sought.

You can find more information on salmon poisoning disease on the Washington State University website.

Cooked salmon, however, is an excellent food for dogs and offers benefits such as boosted immune system, stronger joints, bright eyes, and improved cognitive function.

5.1 – Canned Salmon And Salmon skin:

Dogs can eat salmon skin so long as it has been cooked thoroughly and is free from seasonings.

This is also true of plain canned salmon that has been canned with, no oil or other additives. Added oils in an oily fish can make a dog obese very quickly.

Canned salmon often includes fish bones but these are very soft, safe to eat, and will not cause any gastrointestinal issues, and they are also an excellent source of calcium.

6. Can Dogs Eat Sardines

Sardines are excellent fish to feed your dog and have a high nutritional value.

As they are small and only have a short life span, their overall exposure to heavy metals and toxins is minimal; thus making them less of a threat than larger, longer-living fish.

Sardines also have very soft bones and do not need deboning before being given to your dog. In fact, sardine bones are highly digestible and are also an excellent source of calcium.

7. Can Dogs Eat Tilapia

Tilapia is rich in phosphorusVitamin Dfolate, and potassium and low in mercury levels, making it excellent for dogs.

Vitamin D is essential for strong bone growth, and folate can help with intestinal problems in your dog.

Farmed tilapia, however, is low in Omega-3s because these “farmed fish” don’t eat phytoplankton and aquatic plants.

These fish are usually fed on GMO corn and soy meal-based diets.

This means that they are also low in nutritional value and have a higher risk of parasitic infection.

In addition to this, farmed fish, in general, are often fed low-quality foods and dosed with antibiotics, pesticides, and hormones in large quantities.

If you must buy farmed fish, then look for the Aquaculture Stewardship Council (ASC) seal.

Farmed fish-bearing, this seal will be safe for your dog to eat.

8. Can Dogs Eat Tuna

Tuna is a long-lived and large sea fish.

Long-lived and large sea fish contain higher levels of mercury compared to other fish as the larger the fish and the longer it lives, the higher the concentration of mercury that is found within it. 

For this reason, there is a fair amount of debate about whether or not; it is entirely safe for dogs. (The great fish debate).

Signs of mercury poisoning in dogs include:

  • Hair loss
  • Anxiety or nervousness
  • Blindness
  • Kidney damage (inability to urinate, abdominal swelling)
  • Loss of coordination
  • Loss of feeling in paws
  • Tremors
  • Vomiting blood
  • Watery or bloody diarrhea

All that being said, canned tuna and shrimp remain the highest consumed tinned fish in America. And many dog owners would argue that tinned tuna is a favorite dog treat. 

Skipjack tuna has the least amount of mercury at 0.144 parts per million which are low to medium on the risk scale, whereas Bigeye tuna has 0.689 parts per million.

Tuna is very high in protein, minerals and vitamins, and omega-3 fatty acids, which are essential for a glossy coat, bright eyes, and a healthy heart.

However, if your dog is of a small breed, maybe it would be best to give tuna a miss due to the higher mercury levels and salt content present in this deep-diving fish.

9. Can Dogs Eat Squid / Octopus

Most dogs can eat squid and octopus without any problems although squid is susceptible to herring worm disease and so should be frozen for at least 7 days at – 4°F / -20°c to kill off any potential parasites.

They are protein-rich, low in fat, and high in essential vitamins and vitamin B enzymes. 

Squid and octopus are also rich in zinc and copper which aids tremendously in the production of red blood cells and the strengthening of the immune system.

Final Thoughts On Fish For Dogs

There is a way to prevent your dog from getting parasites from raw fish; freeze it for 7 days or 3 weeks at -4°F / -20°C minimum as the freezing will kill any parasites in the fish, making it safe for your dog to eat.

Always introduce a new food to your dog’s diet in small increments and check for unexpected reactions.

If you are thinking about changing your dog’s diet and introducing more fish or implementing a raw diet please speak to your veterinary first.

Links to related articles:

When In Doubt About Foods Safe For Dogs To Eat, Ask A Veterinarian For Advice

If your dog is acting strangely or experiencing minor symptoms of weakness, lack of coordination, vomiting, diarrhea, etc., and you think they may have consumed something they shouldn’t have, seek a veterinarian’s attention immediately. If you wait too long, your dog might not make it.

What If You Cannot Reach Your Veterinarian?

In an emergency, when you cannot reach your veterinarian, immediately contact your local animal emergency clinic or call the animal poison hotline at 888-232-8870. You can also try the ASPCA Animal Poison Control Center at 888-426-4435.

Disclaimer:

The contents of this page are not veterinary advice. Several factors determine what is toxic to your dog including age, size, health, weight, allergies, and amount of product ingested to name but a few. If you think that your dog has eaten something potentially toxic please seek veterinary advice as soon as possible.

A proud father of two boys, an amateur actor, and a green living enthusiast, Mark has been sharing hints, tips, and sustainable living content on his website Sustainability Dad since august 2019.

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