Fish for Dogs - Studies on Benefits and Side EffectsWe know fish is good for people. But what about leaving some of your fish for dogs?

And what about other types of ocean dwellers, like crabs, shellfish and other seafood? Is it safe and healthy to give seafood to dogs?

Fish is one of the healthiest foods humans can eat. It’s full of vital nutrients, vitamins and protein. We know that fish is a good source of vitamin D and omega 3 fatty acids. Does fish benefit dogs in the same way?

In short, feeding fish to dogs should be seen as a supplement. Too much fish for dogs may cause harm, but allowing them a little can have great health benefits, and the same applies  to giving fish oil supplements.

Fish, and most other seafood, is low in calories and lacks many nutrients, thus a fish or seafood heavy diet for dogs is inadvisable. Several studies have shown adverse effects of giving too much fish for dogs, but more research has concluded that moderation is key.

The best results are achieved when owners provide their pets with a recommended (usually weekly) serving of a healthy fish choice.


Fish has a high protein/amino acid profile

Protein is the most important macronutrient in a healthy dog’s diet.

Proteins are the building blocks of organ tissues and cells. Amino acids contained in protein are responsible for many processes in the dog’s body, including maintenance of smooth workflow and digestion.

Fish is known for a very high protein content. Lean fish choices also have superb protein-to-calorie ratio.

Buying some fish for dogs on occasion is an easy way to increase your canine’s protein intake without adding too many extra calories.

Amino acids contained in protein help to regulate hormones, build muscles, fix tissue in tendons, ligaments, cartilages, and maintain healthy skin, hair, and nails. Fish may also help dogs with arthritis.

Unfortunately, research with dogs is still lacking; however, human studies have made the benefits of amino acids clear [1, 2, 3].

A constant stream of high quality, high amount of protein and amino acids can be seen as a possible preventative measure for future joint and arthritis problems in dogs.

More benefits of high-protein diets in dogs

A study from 1996 [4], where four groups of dogs were tested on different sources of protein, concluded that a high protein diet is beneficial for dogs specifically when treating behavioral problems.

Another famous older study has concluded [5] that ancestors of our domesticated dogs used to live on approximately 90% of protein.

Hence some experts suggesting that for the best result, pet owners might consider providing their dogs with the same type of diet in terms of fat content and protein saturation.

Even though we wouldn’t go as far as saying that this “old school” diet is the way to go nowadays – especially considering the way our dogs have evolved [6] – fish for dogs is definitely beneficial in terms of keeping high protein content and low calories in the diet.

Necessary fats content in fish

Fish for Dogs Healthy or HarmfulSomething many pet owners don’t realize is that dietary fat is not the kind of fat that will be found in your dog’s adipose tissue.

A good amount of healthy fats is essential for a well-balanced canine diet, and they’re next on ASPCA’s list of essential nutrients.

Fats contained in fish will help your dog’s body in absorbing fat-soluble vitamins, minerals, and other nutrients.

It will also promote building of the necessary layer of insulation to keep the body warm or cold, or protect internal organs.

Fish for dogs to treat joint problems

There may be even more benefits of fish for dogs’ joints and tendons, and possibly even canine arthritis.

Oily fish provides a substantial amount of dietary fat that is enriched with essential fatty acids, omega-3 and omega-6, a type of carboxylic acids that are adept at reducing inflammation in the body.

The greatest benefit of allowing a healthy amount of essential fatty acids through natural sources like fish for dogs is its ability to treat your canine for arthritis and other joint problems, as several studies have suggested [7, 8].

Fish oil supplements for dogs

You have probably heard that it is advisable to give your dogs fish oil supplements.

Usually, commercial salmon oil is used in dog fish oil supplements. These may help with inflammation, arthritis and other joint problems.

Although fish oil supplements for dogs were seen to work well, moderation would be the key here.

Some studies have found multiple adverse effects [9] of too much of a good thing.

More benefits of high-fat diet in dogs

Furthermore, one of the more recent studies from Cornell University have concluded that high-fat diets can significantly increase the already incredible sense of smell in dogs.

A case-study [10] has found a correlation in positive effects of fish oil in dogs with epilepsy.

A different study from 2008 [11] has found a positive effect of essential fatty acids for dogs with dermatitis.

Remember, too, that similar to humans, your dog’s age will have an impact on the type of diet they should be administered.

As dogs get older, nutrients like omega-3 fatty acids and various antioxidants become much more important, while young puppies require more protein to help their bodies and organs grow and develop.

Pairing fish with other foods is essential

Seafood and Fish for Dogs - Science on Benefits & Side Effects

Given the above evidence, it’s safe to conclude that fish and many seafood products would be a great addition to a healthy dog’s diet.

However, fish for dogs should never be the foundation of their diet, and must not substitute proper commercial dog food diet that have been specifically designed to hit all the marks of a canine’s nutritional requirements.

Dog experts still argue on the matter, but science has already shown that canines require a type of carbohydrate in their diet, as well as certain vitamins and minerals for a completely healthy life and dietary regime.

Carbohydrates not only serve as an additional source of energy and tissue building, but are also important for a dog’s digestive health.

A dog’s body breaks down carbohydrates into glucose, which feeds muscles and organs to maintain functionality, and fiber, to ensure everything is digested and distributed well.

Lack of carbohydrates and vitamins in fish

Some dog experts often advise completely against any type of carbohydrates for dogs, and although it is the proteins and fats that are indeed the staple of a healthy diet, some carbs are still important [12].

Unfortunately, fish for dogs alone will not provide the sufficient amount of carbohydrates.

In fact, very few types of seafood will carry any amount of carbohydrates whatsoever.

Similarly, your dogs will also not get all the required vitamins and minerals from a diet that consists solely of fish or seafood.

Certain minerals and vitamins (Vitamin C, Vitamin K, Vitamin E, probiotics and a few others are the most common suspects) are absolutely vital to a dog’s overall health, and are not found in high enough quantities in various types of fish or seafood.

Structuring your dog’s diet

By now, you must already know the amount of daily calories your dog requires based on their size, age, and activity level.

With that in mind, you can develop an adequate weekly schedule to better aid your pet in proper digestion and nutrient acquisition. Feel free to add some fish in there, too.

It will take some time to find the sweet spot, but once your canine finds something they like, you don’t need to change it for a long time. Just make sure to hit all nutritional marks on a weekly (not daily) basis, and there shouldn’t be any menu-tweaking needed.

Too much of a good thing

Lastly, just like with everything else, too much fish for dogs could be worse than none at all.

Remember that changing your dog’s eating habits must always be closely looked at.

The first thing you should do after you decide to go for the benefits of seafood and fish for dogs in the diet is consult with a vet. All dogs are different, and the same goes for their diets.

Once you’ve decided to include fish for dogs at your home, make sure you’re aware of the potential side effects of fish when given too much, too often.

Side effects of feeding fish to dogs

Fish for Dogs - Healthy or Harmful - Science on Benefits & Side Effects

Some studies have indeed found adverse effects of giving too much fish to dogs.

Adding fish and seafood to your dog’s weekly meals may be a very healthy choice in many ways, there are things you should watch out.

First of all, whenever you reinforce your canine’s diet with new food selections, especially if that’s some type of fish or seafood, you should start them out with a sample just to make sure that it agrees with their system and does not upset their stomachs.

Most dogs have no trouble processing fish, but it is always better to err on the side of caution.

Common issues with fish

Fish bones can cause some major issues.

Aside from complicating digestion, fish bones being so sharp can cause lacerations. They can puncture holes in the dog’s stomach and digestive tract.

However, you should be able to remove all of those pesky fish bones with your fingers. Alternatively, run the fish through a meat grinder or use any other popular method. Buying fish without bones is also an option but watch out for processes stuff.

Mercury may possibly be an issue as well, regardless of where you purchased the product.

For example, one study have found [13] that Alaskan dogs that live on a diet high in fish had very high levels of mercury that negated all the positive effects from omega-3 fatty acids.

Preparing fish for dogs

Properly cooked fish should be administered to your dog because unlike with raw meat, raw fish cannot be handled in the same proper way, unless you’re paying a top buck for it.

One of the most well-known fish-related deadly health problems in canines is the salmon poisoning disease (SPD), which has been observed in dogs of mostly North American coast [14].

Neorickettsia helminthoeca parasite is the cause of SPD, but it can be killed when salmon is cooked well.

Finally, if you’re looking to give your pet the best nutrition possible, you need to stay away from fried or breaded fish and seafood.

Processed fish foods are considered to be acceptable only for humans, and aside from very high calorie content, such methods of preparing fish can cause your dog a lot of digestive issues and have many other negative health effects.

So is it safe to give fish to dogs?

In conclusion, a little seafood or fish for dogs on a weekly basis under controlled supervision can be very beneficial.

Too much fish given to dogs can become dangerous with adverse consequences.

A good choice of unprocessed fish is important, and so is cooking it properly to avoid any diseases.

Lastly, whenever there’s a change of your dog’s diet, it is always imperative to do the necessary research and discuss your options with a veterinarian. All dogs are different and they take differently to certain diets and their changes.

Not all foods that work for us will work for the dog, and with so many items available on the market today, it’s always better to be safe.

[toggle title=”References“]
  1. Bainbridge J et al. Methionine aminopeptidase-2 blockade reduces chronic collagen-induced arthritis: potential role for angiogenesis inhibition. Arthritis Res Ther. 2007;9(6):R127
  2. Maccagno A et al. Double-blind controlled clinical trial of oral S-adenosylmethionine versus piroxicam in knee osteoarthritis. Am J Med. 1987 Nov 20;83(5A):72-7 
  3. Kanaley JA et al. Growth hormone, arginine and exercise. Curr Opin Clin Nutr Metab Care. 2008 Jan;11(1):50-4 
  4. Dodman NH et al. Effect of dietary protein content on behavior in dogs. J Am Vet Med Assoc. 1996 Feb 1;208(3):376-9 
  5. Landry SM et al. The diet of feral carnivores: a review of stomach content analysis. J Am Animal Hosp Assoc. 1979 Nov/Dec;15:775-781
  6. Larson G et al. Rethinking dog domestication by integrating genetics, archeology, and biogeography. Proc Natl Acad Sci U S A. 2012 Jun 5;109(23):8878-83. doi: 10.1073/ pnas.1203005109
  7. Moreau M et al. Effects of feeding a high omega-3 fatty acids diet in dogs with naturally occurring osteoarthritis. J Anim Physiol Anim Nutr (Berl). 2012 Jul 14. doi: 10.1111/j.1439-0396.2012.01325.x
  8. Mooney MA et al. Evaluation of the effects of omega-3 fatty acid-containing diets on the inflammatory stage of wound healing in dogs. Am J Vet Res. 1998 Jul;59(7):859-63
  9. Lenox CE, Bauer JE. Potential adverse effects of omega-3 Fatty acids in dogs and cats. J Vet Intern Med. 2013 Mar-Apr;27(2):217-26. doi: 10.1111/jvim.12033
  10. Scorza FA et al. Positive impact of omega-3 fatty acid supplementation in a dog with drug-resistant epilepsy: a case study. Epilepsy Behav. 2009 Aug;15(4):527-8. doi: 10.1016/ j.yebeh.2009.05.013
  11. Bensignor E et al. Efficacy of an essential fatty acid-enriched diet in managing canine atopic dermatitis: a randomized, single-blinded, cross-over study. Vet Dermatol. 2008 Jun;19(3):156- 62. doi: 10.1111/j.1365-3164.2008.00670
  12. Axelsson E et al. The genomic signature of dog domestication reveals adaptation to a starch- rich diet. Nature. 2013 Mar 21;495(7441):360-4. doi: 10.1038/nature11837
  13. Kriya L Dunlap et al. Mercury interferes with endogenous antioxidant levels in Yukon River subsistence-fed sled dogs. 2011 Environ. Res. Lett. 6 044015 doi: 10.1088/1748-9326/6/4/044015
  14. A. J. Booth et al. Salmon Poisoning Disease in Dogs on Southern Vancouver Island. Can Vet J. Jan 1984; 25(1): 2–6 

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