In the previous Blog, we discussed the ongoing debate about raw versus cooked food diets for pets.
Here we are going to address some lingering questions.
Should it include raw meat or cooked meat?
Many of us in the veterinary community, including myself, have seen first-hand the health and vigor of dogs and cats fed raw diets. These animals just 'shine' in all respects; the experiential findings based on years of observations by dedicated holistic veterinarians and animal nutritionists support this conclusion. To criticize all raw diets on the basis that they are inherently harmful is misleading, and conveys an inflexible message.
In the USA, the FDA’s Center for Veterinary Medicine controls the pet food industry, and this organization mandates a zero-tolerance policy of Salmonella for all pet foods, not just the ‘cooked’ products. Further, the top raw food manufacturers also test each batch of food before releasing it into the marketplace.
As anyone who follows pet food recalls knows, commercially produced kibbled products and treats are recalled on a regular basis due to contamination with Salmonella spp., E. coli and Campylobacter spp.
Should the meat be grass-fed rather than grain-fed?
Grass-fed meats are preferred over those meats derived from grain-fed animals, because grain residues reside in the flesh of the carcass. The most commonly fed grain is corn, which often is of genetically modified origin (GMO) and field grade. Rice, soy and sorghum are also commonly fed. Additionally, some pets are intolerant of these grains.
What about fish?
Both white-colored fish and salmon and their oils are common ingredients in pet foods and provide an important source of the omega-3 fatty acids needed to sustain the skin and coat, brain and other body metabolic functions. The fish should be farm raised or at least be assured to be free of mercury.
What about the need for some vegetables and fruit in a complete diet?
Unlike cats that remain primarily as obligate carnivores and need some meat, dogs have evolved from their ancestral wolves to be obligate omnivores. They have adapted to domestication by developing three additional genes that allow them to digest and assimilate starch. Regardless, an all-meat diet is not balanced for long term use, especially in dogs, and so some vegetables and fruit (making up 30-70% of the total diet) should be included for roughage, fiber and pro-biotics. Some also add organic tripe.
Dogs (and even cats) can be healthy when maintained on strictly vegetarian diets, although these diets must be nutritionally complete and balanced. Pet caregivers should regularly monitor urinary acidity and should add products such as cranberry extracts, if urine becomes too alkaline (i.e. pH > 7.0).
Suggested vegetables and fruits include: Carrots and green beans, as functional carbohydrates, are a source of soluble fiber, and have anti-inflammatory and antioxidant effects. Simply chop them up into small raw pieces, or lightly steam them as this helps with digestibility. We also like spinach or kale, and zucchini.
Apples, pears and bananas protect the heart and help control diarrhea. Apples also improve brain health, lung capacity and cushion joints; whereas bananas help strengthen bones and control blood pressure. Pears provide a rich source of fiber. Also use fresh or frozen blueberries and cranberries, plus watermelon.
What about taurine levels in certain types of dog foods and the possible connection between grain-free diets and dilated cardiomyopathy (DCM), which is also known as canine heart disease (CHD).
The US Food and Drug Administration (FDA) released a statement on July 12, 2018 that it is investigating a possible connection between grain-free diets and DCM, which is also known as CHD.
But, many factors need to be considered in addressing this situation:
- Genetic predisposition
- Scientific research thus far
- Taurine requirements for dogs
- Interaction between foods when passing through the body
- Interaction between foods and the body itself
What we do know:
- Taurine is an amino acid. Amino acids are found in animal-based protein sources and plant sources like soy at varying amounts, depending on the type of meat or plant.
- Taurine deficiency can lead to CHD in humans, cats and dogs.
- All breeds and sizes of dogs can develop CHD. However, CHD is more common in larger and giant breeds such as Great Danes, Boxers, Newfoundlands, Irish Wolfhounds, Saint Bernards and Doberman Pinschers. American and English Cocker Spaniels also have a higher incidence.
- At this time, taurine is notconsidered an essential, food-sourced amino acid for dogs. It is synthesized in the liver from the amino acids cysteine and methionine.
- Although taurine is present in today’s dog food, the label does not need to reflect its presence or meet any minimum requirement.
- Cats, however, dohave a need for food-sourced taurine to prevent CHD; and there is a minimum required amount for cat food.
- Cooking temperature is stated to adversely affect or significantly degrade amino acid levels in foods.
- A published study found, “The amount of taurine that remained in a feed ingredient after cooking depended upon the method of food preparation. When an ingredient was constantly surrounded by water during the cooking process, such as in boiling or basting, more taurine was lost. Food preparation methods that minimized water loss, such as baking or frying, had higher rates of taurine retention.”
- Cysteine is one the essential amino acids that dogs need to form taurine. Another published study by Weiss et al concluded, “Eight (including cysteine) of the 20 standard amino acids decompose at well-defined, characteristic temperatures, in contrast to commonly accepted knowledge. Products of decomposition are simple. The novel quantitative results emphasize the impact of water and cyclic condensates with peptide bonds and put constraints on hypotheses of the origin, state and stability of amino acids in the range between 200 °C and 300 °C.” Put simply, high temperatures do cause the breakdown or change these amino acids, including cysteine.
- High levels of legumes or potatoes appear to be more common in diets labeled as “grain-free,” but it is not yet known how or if these ingredients are linked to cases of DCM.
- The FDA is simply stating a trend, which no doubt will lead to much needed research.
- The FDA is notdismissing the prior research as invalid. As the FDA puts it, “The underlying cause of DCM is not truly known, but is thought to have a genetic component.”
- The FDA is also notsaying that pet caregivers should stop feeding grain-free foods.
Axelsson, E, Ratnakumar, A, Arendt, MJ, et al. The genomic signature of dog domestication reveals adaptation to a starch-rich diet. Nature 2013; 495: 360–364.
Dodds, WJ, Laverdure, DR. Canine Nutrigenomics: The New Science of Feeding Your Dog for Optimum Health. 2015. DogWise Publishing, Wenatchee, WA, .323 pages.
Ko, KS, Fascetti, A. Dietary beet pulp decreases taurine status in dogs fed low protein diet. J An Sci Technol 2016: 58: August. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4971673/.
Weiss, I, Muth, C, Drumm, R, Kirchner, HOK. Thermal decomposition of the amino acids glycine, cysteine, aspartic acid, asparagine, glutamic acid, glutamine, arginine and histidine. BMC Biophysics, 2018;11(2).
The debate over which type of diet is best for dogs and other pets to live healthy lives and thrive is unlikely to be resolved in the near future. Should it include raw meat or cooked meat? Should the meat be grass-fed rather than grain-fed? What about fish? What about the need for some vegetables and fruit in a complete diet? And finally, the latest pet food scare around the world – what about taurine levels in certain types of dog foods and the possible connection between grain-free diets and dilated cardiomyopathy (DCM), which is also known as canine heart disease (CHD).
If you’ve stopped feeding grains to your companion dog because of this recent issue, please think back to the many reasons why you stopped. It could be to prevent the “leaky gut” syndrome, to help curb food sensitivities or intolerances to a particular grain, to maintain optimal weight, etc.
Proponents of raw food diets cite numerous benefits, including:
- Closely mirrors the evolutionary diet of wolves and wild
- Dogs are carnivores (actually, cats are truly carnivores and dogs have evolved to become obligate omnivores) -- designed to consume raw meat, bones and
- Dog caregiver controls ingredient selection and
- Higher in enzymes, vitamins and minerals than cooked
- Greater nutrient availability than cooked
- Improved skin and coat.
- Reduced or eliminated ear infections.
- Fewer, less bulky, less foul-smelling stoo
- Increased energy
- Reduced incidences of chronic
- Enhanced immune function and overall optimum
Opponents of raw food diets cite negatives, including:
- May expose humans to higher bacterial
- Lack of documentation that raw-fed dogs live healthier, longer
- Exposes vulnerable dogs to dangerous
- Home-prepared raw meat-based diets are often unbalanced, with deficiencies and/or excesses of certain nutrients.
- Unbalanced raw diets are of particular concern with regard to growing
- Bones, even raw, pose risk of obstruction and
Proponents of fresh, home-cooked diets cite numerous benefits, including:
- Dog caregiver controls the ingredient selection and
- Fresh, whole foods provide higher levels of nutrients than processed commercial
- Nutrients contained in fresh foods are more bioavailable than those contained in processed commercial foods.
- Fresh meat, fruits and vegetables are more species-appropriate than commercial food.
- The next items are those listed above as the last 7 for raw diets.
Opponents of fresh, home-cooked diets cite numerous negatives, including:
- Are nutritionally unbalanced and can contribute to long-term vitamin/mineral
- Are often those invested in the mass-market commercial pet food industry.
- Many mainstream veterinarians are also opposed to home-prepared
- We believe the vast majority mean well and base their beliefs on information provided by the commercial pet food industry.
The main objection veterinarians typically raise regarding raw meat-based diets has more to do with human food safety issues than the validity of the diet for the animal. It goes without saying that proper food handling and safety techniques should be used when feeding a raw meat-based diet, just as they should when handling raw meat prior to cooking. In addition, vulnerable individuals, such as young children, the elderly, sick or immune-impaired people, young puppies or ill dogs should not be exposed to raw meat due to potential health risks. Common-sense precautions can greatly minimize the potential of bacterial contamination from raw food.
In our view, neither a raw nor cooked diet is inherently “better” than the other. We work with many dogs that thrive on raw food diets, and others that do not do well on raw foods but thrive on freshly prepared cooked foods. As we keep coming back to, every dog is an individual, and we believe that individual needs should outweigh a devotion to any one way of feeding. od diet is far superior to the highly processed, species-inappropriate
What About Food Recalls
Many of us prefer to believe that the foods we and our pets eat are healthy and safe, even if we and they overeat fatty foods or those with a high glycemic index (high sugars and starches). However, both the human and pet food industries have more recently been inundated with food recalls for contamination with microbes including bacteria, viruses and parasites. Every food type has been implicated, even candies.
Bacterial, Viral & Parasite Contamination
Food recalls in human and pet foods have primarily concerned contamination with Salmonella (many sources from animals, fish and plants), Listeria (mostly from bovine species), and Campylobacter bacteria, Hepatitis A virus in undercooked shellfish, and parasites like tapeworms.
The most recent pet food recall in the United states was for a cat food that was contaminated with both Salmonella and Listeria spp. and caused acute illness in 2 kittens and one died. It should be noted that the U.S. Food and Drug Administration (FDA) quoted a study from 2004 and stated, “Although L. monocytogenes can infect many animal species, dogs and cats rarely get listeriosis and they usually don’t show signs of disease. One reference mentions only six reported cases in dogs from 1947 to 2000, and the dogs showed a wide range of signs.”
Campylobacter spp. are now considered to be major triggering agents of an acute immune-mediated peripheral nerve disorder in dogs that shares many similarities with Guillain-Barre syndrome in humans. However, there is little information about its relationship to Campylobacter spp. in dogs. Potential risk factors were investigated, particularly consumption of raw chicken in 27 client-owned dogs suspected of suﬀering from it and 47 healthy dogs, client- or staff member owned. Where fecal samples were collected within 7 days from onset of clinical signs, the clinical cases were 9.4 times more likely to be positive for Campylobacter spp. compared to control dogs. Further, a signiﬁcant association was detected between aﬀected dogs and the consumption of raw chicken (96% of cases; 26% of control dogs). Dr. Frieda Jorgensen, Public Health England, states 90% of Campylobacter cells are killed slowly by freezing, making it much less likely that the bacteria will be passed to humans. The temperature range for growth is 30- 45°C, with an optimum of 42°C. Survival at room temperature is poor, but Campylobacter can survive for a short time at refrigeration temperatures – up to 15 times longer at 2°C than at 20°C.
Escherichia coli is a common fecal contaminant that can be found in many consumed human and animal foods.
Dodds WJ, Diagnosis of canine food sensitivity and intolerance using saliva: report of outcomes. J Am Hol Vet Med Assoc 2017/2018; 49:32-43.
Dodds, WJ, Laverdure, DR. Canine Nutrigenomics: The New Science of Feeding Your Dog for Optimum Health. 2015. DogWise Publishing, Wenatchee, WA, .323 pages.
At the start of my work as a vet, the owner of an elderly female dog, Ginger, with a chronic renal disease, brought her in to receive the annual vaccination [core diseases vaccines, Canine Parvo virus (CPV), Canine distemper virus (CDV) and Canine adeno virus (CAV)].
The first question was “is it really necessary to automatically revaccinate every year for core vaccines, especially in an elderly dog with chronic health problems?”.
Intrigued by the question, I looked for answers.
I have come across a number of studies showing proof that core diseases vaccines may last for several years. The high prevalence of adequate antibody levels in a large population implies that annual revaccinations against CPV, CDV and CAV aren’t necessarily needed.
The scientific arguments in favour of less frequent revaccinations are traditionally based on antibody titers. Protection against most viral diseases is indeed antibody-mediated, and antibodies are easily measured.
Due to these findings the WSAVA (World Small Animal Vaccination Association) Vaccination Guidelines states “The presence of antibody (no matter what the titre) indicates protective immunity and immunological memory is present in that animal. Giving more frequent vaccines to animals in an attempt to increase antibody titre is a pointless exercise. It is impossible to create ‘greater immunity’ by attempting to increase an antibody titre.”
Ensuring Ginger was immunized, I took a blood sample and ran the VacciCheck antibody test for the presence of antibodies against core disease. Results were conclusive - Ginger was immunized with regard to all the three core diseases, and so no need for further vaccination.
*Ginger's titer test results by VacciCheck
Needless to say, Ginger's owner was delighted. I imagine that Ginger was delighted as well…