Raw Feeding: The case for and against raw fish and specifically, what about sardines?

The topic of feeding our pets raw food is subject to great controversy in general. Even more so when it comes to more detailed issues and questions such as feeding raw fish. Is it safe? Not related to the question of pet food safety such as cleanliness in raw food handling, but to the issue of is it good or bad for a dog’s health in general?
There is good news and bad news. Let’s get started with the negative: Feeding certain species of raw fish can result in a thiamin deficiency in a dog, which in turn can lead to loss of appetite, reflexes and nerve control, seizures, and in severe cases, death. The problem is most common if raw fish is fed regularly. Thiamin or Vitamin B1 was one of the first water soluble vitamins to be identified. It is required for the normal function of muscles and nerves because it converts glucose to energy and should be provided to a dog at a minimum of 0.01 mg/lbs dog weight daily. Sources for this vitamin are meat, vegetable, fruits, and milk. Thiamin deficiency is often found in pets that are fed substantial amount of raw fish. Herring, smelt, and catfish contain large amounts of thiaminase. Thiaminase is an thiamin destroying enzyme. Clinical signs for thiamin deficiency are anorexia, ataxia, vomiting, short convulsions, dilation of the pupils and ventroflexion of the neck. Affected animals can die unless treatment with thiamine is administered. In most cases a complete recovery can be expected in treated cases unless severe central nervous system has occurred.
Therefore pets should not be fed raw fish exclusively. Cooking fish prior to feeding will destroy the thiaminase enzyme, i.e. feeding cooked fish poses no problem. Obviously, cooking also reduces the risk of any parasitic infections being passed onto your pet from the raw fish. Equally obvious is the fact that with cooking, i.e. heat processing, we loose the benefits we wanted to gain by feeding raw. More a safety issue requiring observation during feeding is the fact that fish bones can be an obstruction risk to your dog.
But now to the positive side of it:
Variety in the diet is essential for your animal’s health. Every pet has its preferences, and it is important to listen to those too. Whole researching this topic I visited many of the plentiful available raw feeding sites on the Internet and have not come across any that would recommend against feeding raw fish. That is of course exclusive of those species included in the aforementioned list of thiamine deficiency causing herring, smelt and cat fish.
Of course there is an entire army of, let me call them less educated, people out there making their case against feeding sardines. Like I found this real dumb comment on one of the blogs: “Why would you even consider feeding sardines to a dog? I mean, seriously. Think about it. no, do not feed your dog sardines! It is wrong on every level. A good quality dog food (I prefer Purina one) is sufficient. But no sardines! Yuck! Fish breath! If you want to give him fish oil for his coat, then go to the pet store and get dog-approved fish oil capsules. Yuck! What are you thinking???!” Such ignorance, whether it was written by a child or under the influence of something maybe not so healthy for the writer, simply doesn’t need any serious pet owner’s attention and as one blog participant commented, there is really nothing more to say but “Whoever said PurinaOne is a good quality dog food needs some help, I pity their dog.”. Let’s close this case right here, my point is, don’t listen to everything you see out there in cyber space. I have to say though, that I found way more intelligent comments on other blogs, all resulting in a throughout positive attitude and all in agreement that feeding the right raw fish is a positive thing to do.
I went on to other sites and it appears as if everybody is pretty much on the same page. There is nothing wrong with feeding raw fish. Except when it is fish rich in the Vitamin B destroying thiaminase, which appears to be applicable to some 50 species of fresh water and not to salt water fish. Jane Anderson, a breeder of Great Danes, boxers, Portugese Water Dogs and other breeds reports that she feeds the dogs at least one serving a week. The fish on average weigh between 1 and 2 lbs. The types of fish she says depends on whichever is most economical that week and could be blackfish, whiting, red fish, mullet, sardines, mackerel, etc.. She sometimes feeds eel if available and on occasion prawns, shark, and crab. If raw prawn shells are available, these are fed to both the cats and the dogs. She claims that her dogs love the fish heads. While for dogs that haven't experienced fish, the whole experience can be a bit overwhelming, her preference for fish is that it is fresh, whole, with scales and fins intact, and the guts still in. This then provides the dog with the ever so important "whole" food requirements. She comments with regards to canned fish that canned is only an option if whole raw fish is not available. After all, it is processed food and nothing compares with raw whole, fresh fish. And about fish bones: “some people worry about fish bones. As long as the fish is fed raw and preferably in its entire form, bones should not be an issue. I have fed fish to my dogs for over 10 plus years, and I have both top quality show dogs and companion animals. If I didn't think fish was a fabulous food source, I certainly would not feed it. I introduce fish to puppies from 4 weeks of age. I mash whole fish into their dinner and they learn from an early age to appreciate this food type. I recommend introducing fish as early as possible to dogs.” And she closes with a word of warning: “Before you go out and buy fish to feed your dog, remember it does take some dogs some time to get used to it. I'd recommend starting off with a small amount of fish at a time. Cats usually take to fish very easily.”
Some other sites are reporting of salmon poisoning, which has been recorded in cats, which contracted the disease from eating raw salmon or trout. This disease occurs within 2 weeks of the ingestion of infected food and causes the following signs: Depression, fever, lymphadenopathy or swelling of the lymph nodes, oculonasal discharge, haematemesis or vomiting blood, diarrhea, death, about 90% in untreated cases. Some fish are particularly high in oil content, and pansteatitis or yellow fat disease is caused by the intake of too much fat in the absence of adequate antioxidant. Red meat tuna has been reported to be particularly involved as a cause of this in cats. The cause of the disease is accumulation of peroxides, the end product of rancidification of fat, in the cats adipose tissue causing yellow brown discoloration.
And finally I ended up back at one of my old friend’s sites. This time it was Steve Brown, co-author of “See Spot Live Longer”, who comments under “Sardines and Eggs: Natural, Affordable Omega-3 Treats for Your Pet”. Though, surprisingly to me, he does not address the sardine as a raw feed item but in its canned form in oil, he says about the nutritional advantages: “The benefits of including long chain omega-3 fatty acids in the diets of humans, dogs and cats are well documented. Fatty acids play a major role in the functioning of the immune system and the maintenance of all hormonal systems in the body. Protection against heart disease, progressive retinal atrophy and support for brain development in the womb are just a few of the many benefits seen when these critical fats are included in our diets and those of our animals. Puppies must be supplied with sufficient DHA before birth in order for their brains and nervous systems to develop properly. If the diet of the mother is deficient in DHA, her body will supply it for the puppies as best she can, but she may never recover her optimum level, and puppies may not get enough. Puppies that do not eat enough omega-3 fatty acids will never reach their full potential. Omega-3s are critical to the functioning of the immune system and the endocrine system. Dr. John Bauer, a leading veterinary nutritionist, wrote, "Omega-3 fatty acids are critically important in pet neuromuscular development, skin health, and coat quality." (1) Dogs and cats need about 1-1.5 grams of long chain omega-3 fatty acids per 100 pounds of body weight.
The evolutionary diet of dogs and cats contained a much higher percentage of omega-3 fatty acids and fewer saturated fats than today's domesticated plants and animals normally provide, just as the diet of humans is radically different in this respect than that of early man. It's our opinion that long-chain omega-3s are essential, just as they are for humans. Pet food regulators are in the process of establishing minimum requirements for omega-3 fatty acids, but most dry and wet foods to don't contain these nutrients. Fish oil is an excellent source of both DHA and EPA Fish oils can be excellent, but they spoil easily, and quality varies considerably. Distilled oils have no contaminants, but they are highly processed foods. We use whole foods whenever we can to obtain nutrients in as close to their natural state and form as possible. In this case, it's easy! Sardines: Omega-3s in Their Natural State: Sardines are an efficient and economical way to eat omega-3s (EPA, DHA) for all of us. They may be far more popular with cats and dogs than with humans, for whom sardines are often an acquired taste! Sardines are the best choice because of the omega-3s they supply, and they don't have the heavy load of contaminants carried by larger fish either. They are small fish or immature members of a larger species, thus sardines have not had time to pick up heavy metals in their short lives.
You can add a few sardines to provide the fatty acids needed, or you can make a once a week complete meal of them. Bones are included, and the mineral ratios are perfect: Sardines are real food in its whole form. However, this isn't a meal you would want to feed your pet every day! Sardines are one of the most popular treats at our houses. They often don't make it to the bowl. They're shared among the humans and animals as a snack, a perfect high fat, high protein boost to the day. Real food is always better than any biscuit in our dogs' view!
Feeding Considerations: Be aware how much food you are adding to your dog or cat's dish when adding sardines. Reduce your animal's meals accordingly. For small animals, food adds up quickly.”
For those readers interested in the nutrient data for sardines I visited the USDA National Nutrient Database for Standard Reference to find out that there only Atlantic sardines in canned in oil form, drained solids with bone or Pacific sardines in canned in tomato sauce form are available for nutrient data review. Sardines contain the following nutrients: Protein ((amino acids: Tryptophan, threonine, isoleucine, leucine, lysine, methionine, cystine, phenylalanine, tyrosine, valine, arginine, histidine, alanine, aspartic acid, glutamic acid, glycine, proline, serine), water, lipid fatty acids, ash, minerals (calcium, iron, magnesium, phosphorus, potassium, sodium, zinc, copper, manganese, selenium), vitamins (Vitamin C, thiamin, riboflavin, niacin, pantothenic acid, Vitamin B6, folate, choline, Vitamin B12, Vitamins A,E,D,K.

You of course have to draw your own conclusion. But I figure that with what I have learned here, sardines, because of their calcium, Omega-3 fatty acids and Vitamin A and D content are a great way to provide yet another type of raw food to my pets therefore helping me in my quest for variety and for some reason I have the feeling the experience of eating a real whole sardine will be a fun food for them as well. That is for feeding whole sardine. One other option available is feeding one of the readily prepared ground raw sardine formulas. For example, Primal makes 2 varieties: One is called the Sardine Grind and contains 100% sardine meat, finely ground bones as calcium source and organs, containing 10% organ meat featuring a 1.4 to 1 calcium to phosphorus ratio consisting of wholesome hormone, antibiotic and steroid free ground meats, meaty bones and organ meats for those pet owners who prefer to add their pets’ favorite fruits, vegetables and necessary supplements. The second one, a Sardine Mix, is made of 80% sardine and 20% produce, calcium source is finely ground sardine bone, the calcium to phosphorus ratio is 1.37 to 1 and has a 10% organ meat content. This mix consists of wholesome ground hormone, antibiotic and steroid free meats, meaty bones, organ meats and finely ground certified organic fruits and vegetables for those pet owners who prefer to tailor their pets’ individual supplemental needs. Main ingredient for both products are whole sardines including bones and innards and the manufacturer says about sardines that they provide superior levels of Amino and Essential Fatty Acids. In addition, finely ground fresh sardine bones allow for optimum levels of calcium. As I pointed out earlier, Primal too does not consider sardines to be a stand alone diet and recommends these products for supplemental feeding only.
References/sources:
(1) Bauer, John. “Fatty acid metabolism in pets.” Feed Management, March 2000.
Steve Brown and Beth Taylor “See Spot Live Longer”
Feeding fish to your cats & dogs by Jane Anderson
Foods to Avoid Feeding Your Dog Veterinary & Aquatic Services Department, Drs. Foster & Smith
NJ Boxers.com Unofficial Boxer Site for All Official Boxer Lovers dedicated to BARF