It’s A Dog’s Breakfast - More Answers and a Summing Up

This is the final installment of answers to the questions and comments posted by readers of my feature series "It's A Dog's Breakfast."

Developing immunity to Salmonella infections
One reader asked whether repeated exposure to Salmonella in food would increase the resistance of a person or a dog to infection. In theory, the answer should be “Yes”. In practice, this might not occur – or might be only partially effective, at best.

There are at least 2,000 strains of Salmonella, many of which are immunologically distinct from each other. Resistance to one strain might confer at least partial resistance to other closely-related strains, but not to strains that are less closely related. This is an ongoing problem for researchers who are trying to develop Salmonella vaccines for cattle and poultry.

The following articles illustrate the complexity of the immune system and its response to Salmonella.

• Clare, S., et al. 2003. Intracellular adhesion molecule 1 plays a key role in acquired immunity to salmonellosis. Infection and Immunity, Vol. 71, No. 10, pp. 5881-5891.
• Mastroeni, P., and N. Ménager. 2003. Development of acquired immunity to Salmonella. Journal of Medical Microbiology, Vol. 52, pp. 453-459.
• Mittrucker, H.W., and S.H. Kaufmann. Immune response to infection with Salmonella typhimurium in mice. Journal of Leukocyte Biology, Vol. 67, No. 4, pp. 457-463

The importance of good food-handling and sanitation practices
This is fundamental to all food preparation - human and animal. In my opinion, attention to proper food handling practices can mitigate, but not eliminate, the risk of feeding a raw diet.


Accessing “Food Safety: Old Habits, New Perspectives”
Google Books offers free access to portions of my book. To take advantage of this access, go to Google Books Advanced Search, type the title of the book in the Title Search box and hit the “return” key on your computer keyboard. You can then either browse some pages of the book or search for specific topics.

My book is also available in at least 180 academic and government libraries world-wide. To find the library nearest you, go to WorldCat, enter your city or zip code and hit the “return” key.


My credentials
Several readers asked for more details about my professional background and credentials. I am a graduate of McGill University (Honours BSc. in Microbiology and Immunology) and the University of Toronto (MSc. in Mycology). I am a Past President of the Canadian College of Microbiologists. Here are a few of the things I have done in my 35+ years as a microbiologist:

• written two books on food microbiology;
• written more than 20 research articles, all of which were published in various peer-reviewed journals;
• addressed an annual meeting of the Japanese Society of Food Microbiology at the invitation of the Japanese government;
• developed and edited a special Salmonella section for the Journal of AOAC International at the invitation of the Journal’s Managing Editor;
• served on the Editorial Board of Food Protection Trends, a publication of the International Association for Food Protection; and
• wrote sub-chapters for The Wiley Encyclopedia of Food Science and Technology, the Encyclopedia of Food Microbiology, and the Compendium of Methods for the Microbiological Examination of Foods.

In Summary
In this series of articles, I have addressed several unsubstantiated claims that appear on web sites and in discussion forums about the safety and benefits of feeding raw food. The purported nutritional benefits of feeding a raw diet are still unproven. Quite simply, no scientifically rigorous nutritional studies have been published to support – or contradict – the claims.

In discussing the safety issues, I have provided links to peer-reviewed scientific research reports and other authoritative sources to support the following statements:

• dogs can carry Salmonella asymptomatically and can pass the microbe in their feces;
• dogs that are fed a diet that is contaminated with Salmonella have a higher probability of carrying Salmonella than dogs that are fed a Salmonella-free diet;
• raw diets have a higher likelihood of being Salmonella-contaminated than home-cooked diets or than processed diets, such as kibble;
• dog saliva cannot reliably inactivate Salmonella or prevent the Salmonella from reaching the dog’s intestinal tract; and
• people can become infected with Salmonella – and other pathogens – through contact with an infected animal.
  

The Bottom Line
Feed your dog a raw diet if you feel you must. But do so with full knowledge and appreciation of the possible consequences.

It's A Dog's Breakfast - Some Answers

Several readers of my five-part series have raised substantive issues in their comments, some of which required additional research of the scientific literature in order to answer accurately. Here is the first installment of answers to readers' questions and comments.


Salmonella in kibble and pet treats
Anonymous (who posted on March 15, 2008 10:32 AM) is correct in pointing out that there have been recalls of kibble and pet treats due to Salmonella contamination. The following products were recalled because of Salmonella in 2007.

• Eight-in-One, Inc. recalled chicken jerky treats for dogs, cats and ferrets. There was one confirmed case of salmonellosis in a dog that was traced to these treats.
• Doane Pet Care recalled a single lot of 55 lb. bags of kibble after FDA found Salmonella in the product.
• Mars Petcare US, Inc. recalled a single lot consisting of 1620 5-lb. bags of kibble and three 50-lb. bags after FDA found Salmonella in the product. The recalled product was distributed in five states.
• Bravo recalled 18,000 pounds of its raw, frozen dog food due to Salmonella contamination.

In 2003, approximately $5.4 billion dollars of dry dog food were sold in the US. Even assuming a premium price of $1.75/lb., this translates to more than 3 billion pounds of kibble. The total amount of kibble recalled in 2007 for Salmonella was 72,930 pounds (based on the information contained in the recall announcements and in the FDA enforcement reports dated August 1st and October 31st). Therefore, the recalled kibble represents less than 0.002% of the annual US sales of dry dog food.


Diet and Dental Disease
More than one reader stated that 80% of dogs develop periodontal disease by age 3. The only source for that statistic that I was able to find is the web site of Merial, a manufacturer of veterinary plaque-preventative gel.

I've identified several articles in scientific journals that address diet and its effect on the development of periodontal disease. I have quoted the main conclusions of these articles. The findings in these research studies show that a hard diet is better at preventing gingivitis and periodontal diseases than a soft diet, and that the most effective preventative of periodontal disease is regular brushing of the teeth and gums. Just as in humans, the mechanical brushing action stimulates and strengthens the gums.

Gorrel, C. 1998. Periodontal Disease and Diet in Domestic Pets. The Journal of Nutrition Vol. 128 No. 12, pp. 2712S-2714S.
"Daily toothbrushing remains the single most effective way of maintaining clinically healthy gingivae."

Gawor, J.P., et al. 2006. Influence of Diet on Oral Health in Cats and Dogs. The Journal of Nutrition Vol. 136, pp. 2021S-2023S.
"These results indicate that feeding a dry food diet has a positive influence on oral health, decreasing the occurrence of mandibular lymphadenopathy, dental deposits, and periodontal disease in cats and dogs."

Clarke, D.E. and A. Cameron. 1998. Relationship between diet, dental calculus and periodontal disease in domestic and feral cats in Australia. Australian Veterinary Journal. Vol. 76 No. 10, pp. 690-693.
The following is the complete Abstract of the journal article. I do not have access to the full article:
"OBJECTIVE: To compare the dental calculus scores and prevalence of periodontal disease in domestic cats eating commercially available canned and dry foods with those in feral cats consuming a diet consisting of small mammals, birds, reptiles and insects. ANIMALS: Twenty-nine feral cats and 20 domestic cats were included in the study. PROCEDURE: A dental chart and dental calculus scores were recorded using the maxillary canine, maxillary third and fourth premolar, mandibular canine, mandibular fourth premolar and first molar teeth on both sides. Periodontal disease was recorded using gingival recession, increased periodontal pocket formation, radiographic alveolar bone loss, osteomyelitis, furcation and root exposure, and the presence of calculus as indicators. RESULTS: Dental calculus scores were significantly higher in domestic cats than in feral cats. There was no statistical difference in the prevalence of periodontal disease between the two groups. CONCLUSIONS: It can be inferred that diet may play a role in the accumulation of calculus, but a diet based on live prey does not protect cats against periodontal disease."

Giardia
One commenter, referencing a 1995 article, questioned whether humans and animals shared the same species of Giardia. I have responded to this already, but will repeat my reply here for the convenience of those who might have missed it.

The 1995 reference has been superseded by more recent research. Please see the following direct quotations from the article Abstracts:

Eligio-García L., et al. 2005. Genotype of Giardia intestinalis isolates from children and dogs and its relationship to host. Parasitology Research, Vol. 97, No. 1, pp. 1-6.
"In this study, genotype A was associated with samples from children and dogs, and, therefore, we could infer zoonotic transmission as a way of getting the disease."

Lalle, M., et al. 2005. Genotyping of Giardia duodenalis from humans and dogs from Mexico using a beta-giardin nested polymerase chain reaction assay. Journal of Parasitology Vol.91, No. 1, pp. 203-205.
"The presence of cysts of the A1 and A3 genotypes in isolates from pet dogs is consistent with their role as reservoirs for human infection, although further studies are needed to confirm the occurrence of zoonotic transmission."

Thompson, R.C. 2004. The zoonotic significance and molecular epidemiology of Giardia and giardiasis. Veterinary Parasitology Vol. 126, No. 1-2, pp.15-35.
"The greatest risk of zoonotic transmission appears to be from companion animals such as dogs and cats, although further studies are required in different endemic foci in order to determine the frequency of such transmission."

Traub, R.J., et al. 2003. Humans, dogs and parasitic zoonoses – unravelling the relationships in a remote endemic community in northeast India using molecular tools. Parasitology Research, Vol. 90, Suppl. 3, pp. S156-7.
"The zoonotic potential of canine Giardia was also investigated by characterising Giardia duodenalis recovered from humans and dogs living in the same locality and households, at three different loci. Phylogenetic and epidemiological analysis provided compelling evidence to support the zoonotic transmission of canine Giardia."

These references make it clear that humans and dogs can and do share some of the same species of Giardia. Furthermore, the articles provide strong epidemiological evidence that dogs and cats can transmit Giardia to humans. The main outstanding question appears to be the frequency of such transmission.

Prevalence of bacterial pathogens in the human food supply
Several "Anonymous" comments mentioned – without providing any supporting evidence – that 80% of food for human consumption is contaminated with Salmonella. That number is grossly overstated. Except for raw poultry, no food products – not even other raw foods – come even close to that incidence of contamination.

It might sometimes seem, as a result of the all too frequent occurrence of pathogen-related food recalls, that our food supply is highly contaminated with Salmonella, Campylobacter, Listeria monocytogenes and E. coli O157:H7. But this is a false impression. Here are some examples of data from research reports. Please click on the live links to access the reports directly.

Consumer Reports published the results of a survey of raw poultry for bacterial pathogens. They found that 83% of fresh, whole broiler chickens purchased at retail stores in the United States were contaminated with Salmonella or Campylobacter, the two leading causes of food poisoning.

The incidence of Salmonella in US shell eggs is estimated at one in 20,000 eggs, or 0.005%, according to a research report published in the International Journal of Food Microbiology in 2000.

A survey of raw domestic and imported seafood published in 2000 in the Journal of Food Protection found that 10% of imported raw seafood contained Salmonella; the incidence in domestic raw seafood was 2.8%.

Several more questions and comments posted by readers remain to be answered. I am working on those answers and will post more information in the next few days.

It’s A Dog’s Breakfast - Part 5: One Company’s Approach

While I was gathering information for this series of articles, a reader pointed me towards Stella and Chewy's, of Muskego, WI, a small company that has adopted some innovative technology to produce its raw pet foods.

The founders of Stella and Chewy's, Marie Moody and Doug Siegal, consulted Dr. James Marsden of Kansas State University, who developed the company’s food safety processes. With Dr. Marsden’s guidance, Stella and Chewy’s have put in place a series of firewalls to help ensure the quality and safety of its products.

Human Grade Ingredients
All of the meat and poultry that goes into the company’s products comes from USDA-inspected plants, and are fit for human consumption.

Hygienic Operating Conditions
Devices that continuously produce an oxidizing vapor are located strategically in the processing area and freeze-dryers. The oxidizing vapor, which kills bacteria but is non-toxic to people, prevents a build-up of contaminants in the air and on work surfaces. In addition, the surfaces of incoming raw materials – especially the meat – are disinfected by exposure to ultraviolet light before further processing.
High Pressure Processing
This technology takes advantage of the relative sensitivity of bacteria and viruses to high pressure, such as is found in the depths of the ocean. High pressure processing kills microbes without using either heat or irradiation, leaving heat-sensitive nutrients intact.

HACCP
Hazard Analysis and Critical Control Points (HACCP) programs have been a mandatory part of many food processing operations for at least two decades. USDA has required the meat and poultry industry to develop and implement HACCP in federally inspected plants since the 1990s; this program, however is not mandatory for pet food manufacturers, which come under FDA's Center for Veterinary Medicine. Under HACCP, a processor must identify every microbiological or chemical hazard that may be associated with each product (Hazard Analysis), determine when and how that hazard can be eliminated or controlled (Critical Control Points), and establish ways to document that the hazard has been controlled in every production batch.


Stella and Chewy’s “4-H” approach is supplemented by a sampling program that includes microbiological testing of every production batch for Salmonella and E. coli O157:H7 by an independent lab. The test results for each production batch are posted on the company’s web site. According to Dr. Marsden, who wrote Stella and Chewy’s HACCP program and developed their food safety processes, the company’s program “...is one of the most innovative and well designed in the nation.”

I haven’t had the opportunity to visit Stella and Chewy’s pet food facility. And, since I no longer have a microbiology lab, I can’t test their products for microbiological contamination myself. Nevertheless, I believe this company is trying hard to produce raw pet food products that are microbiologically safe.

But microbiologically safe raw food is expensive. A 6-ounce package of 12 freeze-dried “steaks” sells for approximately $11.00 (the price varies to a minor degree, depending on the retailer). A one-pound package, which contains 32 “steaks”, costs almost $26.00.

According to Stella and Chewy’s, the recommended daily portion for a 60-pound dog is 12 steaks. This translates to nearly $70.00 per week to feed one dog about the size of a Labrador retriever. Based on US government statistics, that’s enough to feed two five-year old children for a full week. That same dog can be fed a top-quality kibble for less than $50.00 per month.

Pet owners who are trying to choose a healthy diet for their four-legged companions are confronted with a confusing smorgasbord of competing claims and dogmas. Canned food or kibble? Raw food or cooked? White rice or brown? How much fat? How much fiber? How to decide?

In presenting this series of articles, I have tried to help clarify some of the confusion over the nutritional and safety issues surrounding raw pet food diets. I welcome your questions and comments, and will be happy to answer them in follow-up articles.

It's A Dog's Breakfast - Part 4: What's In It For Fido?

We hear a lot of claims from promoters of raw meat diets about the nasty ingredients in kibble and canned pet foods – binders, stabilizers, meat from diseased animals, corn and other grain fillers. In fact, many dog foods, especially the lower-priced products, leave much to be desired. But what, exactly, is in a “raw food diet”? Is it more nutritious than the best commercial “cooked” diets? Is it safe?

The BARF Diet
Dr. Ian Billinghurst is a pioneer in the field of raw pet foods. He published his first book, "Give Your Dog a Bone: The Practical Commonsense Way to Feed Dogs for a Healthy Life" in 1993.

Dr. Billinghurst's book introduced many pet owners to the concept of the "Biologically Appropriate Raw Food" diet, which was an attempt to mimic the natural diet of the dog's wild ancestor – the wolf. The original BARF diet comprised raw meaty bones (usually chicken wings and backs, but sometimes beef, lamb or wild game, including venison), raw eggs, pureed raw fruits and vegetables, and the occasional dollop of yogurt.

The BARF diet, while embraced by some dog owners, was daunting to others. Several years ago, Dr. Billinghurst simplified BARF by introducing a commercial product line, consisting of frozen patties, which is sold through a web site named BARFWorld. The line of products includes "Beef Offal", "Beef Tripe", and "Chicken and Bone Mince" patties. BarfWorld also sells nutritional supplements and "Fruit and Veggies Nuggets".

In 2004, BARFWorld announced that it would be conducting nutritional research “...on the best possible means of feeding our companion animals,” and asked for volunteers to participate in the study. Twenty-eight dog years later, we’re still waiting for the first word on this study.

Raw Meaty Bones Diets
Dr. Billinghurst isn’t the only advocate of raw feeding. At about the same time that he introduced the BARF diet, another group of Australian veterinarians began to promote a different Raw Meaty Bones (RMB) diet. Other raw diet disciples have chimed in with their own variations. All of the diets are built on a foundation of raw poultry or raw meaty bones.

A Balanced Diet?
A supporter of homemade (raw or cooked) diets said in 2003,

“... feeding home-prepared cooked or raw diets has not been proven to control medical problems, based upon prospective, double-blind, statistically significant clinical trials.”

This is still true in 2008. I have searched the scientific journals using PubMed, a search engine service of the U.S. National Library of Medicine, and have not found a single report of even a small, prospective feeding trial.

One study, published in 2001, attempted to address the nutritional content of raw diets. It compared three homemade and two commercial raw diets against the guidelines recommended by the Association Of American Feed Control Officials (AAFCO). The study was inconclusive for several reasons:

• calculation errors, especially of the levels of vitamin D in the diets, forced the authors to publish a correction;
• the study comprised just a single sample of five different diets - not enough to account for day-to-day variation, especially of the homemade diets; and
• its conclusions relied strictly on lab analysis, which cannot predict the extent to which the nutrients can be digested and absorbed.

RMB = Really Microbiologically Bad?
Many pet owners who are considering switching to a raw diet, especially one based on poultry, worry about Salmonella and other food poisoning bacteria. And they have good cause for concern. According to the USDA, 45% of raw ground chicken and 11.4% of whole broiler carcasses in the US are contaminated with Salmonella.

I searched the scientific literature and found three articles that specifically analyzed raw meat diets for bacterial contamination. These studies were limited in size and scope, but the results were consistent.

1. Joffe, D.J. and D.P. Schlesinger. 2002. Preliminary assessment of the risk of Salmonella infection in dogs fed raw chicken diets. Canadian Veterinary Journal, vol. 43 (June), pp. 441-442.
In this preliminary study, the authors tested 10 samples of homemade BARF diets for Salmonella. Eight of the 10 samples contained Salmonella, as did the feces of 3 of the 10 dogs that had been fed the BARF diet.

2. Weese, J.S., et al. 2005. Bacteriological evaluation of commercial canine and feline raw diets. Canadian Veterinary Journal, vol. 46 (June), pp. 513-516.
This study examined samples from 25 commercial raw diets. Fifteen of the 25 samples contained Escherichia coli (but not E. coli O157:H7), 5 samples (20%) contained Salmonella, and 5 contained Clostridium perfringens, another food poisoning bacterium.

3. Strohmeyer, R.A., et al. 2006. Evaluation of bacterial and protozoal contamination of commercially available raw meat diets for dogs. American Veterinary Medicine Association Journal, vol. 228, no. 4, pp. 537-542.
In this yearlong study, 240 samples of commercial raw meat diets were examined for E. coli, Salmonella and Campylobacter. The researchers did not find any Campylobacter, but detected E. coli in just about every sample, and Salmonella in 17 of the 240 samples.


Many producers of commercial raw food diets acknowledge that their products may contain harmful bacteria. Some, such as Nature's Variety, provide their customers with handling instructions to minimize the risk of transmission.

But one raw pet food company has gone several steps farther. To find out more, watch for Part 5 of this series, “One Company’s Approach”, which will appear on Monday, March 17th.

It’s A Dog’s Breakfast - Part 3: Getting Down To Cases

Salmonella and Campylobacter jejuni are the two most common known causes of food-borne human gastrointestinal disease. Both of these microbes are often present in raw meats – especially in raw poultry.

Dogs and cats can carry these bacteria – often without showing any symptoms – and can pass these pathogens along to their human companions. To illustrate, the following is just a very small sampling of reported cases.


1. Wright, J.G., et al. 2005. Multidrug-resistant Salmonella Typhimurium in four animal facilities. Emerging Infectious Diseases, vol. 11, no. 8, pp. 1235-1241.
Salmonella-infected dogs and cats in 3 veterinary hospitals and in one animal shelter transmitted the infection to their handlers. Thirty-six out of 200+ animals and 18 out of 19 people (employees and clients of these facilities) were infected with Salmonella.

2. Sato, Y., and R. Kuwamoto. 1999. A case of canine salmonellosis due to Salmonella infantis. Journal of Veterinary Medical Science, vol. 61, no. 1, pp. 71-72.
A dog with watery diarrhea was diagnosed as being infected with Salmonella infantis. Soil samples taken from the garden in which the dog had been housed before it became ill also contained Salmonella infantis. The dog was treated with antibiotics and recovered.

3. Sato, Y., et al. 2000. Salmonella virchow infection in an infant infected by household dogs. Journal of Veterinary Medical Science, vol. 62, no. 7, pp. 767-769.
A 4 month-old infant, who was suffering from diarrhea, was diagnosed with salmonellosis. Salmonella virchow was found in the infant’s stool and in the feces of two of the three dogs that were living in the same house.

4. Cantor, G.H., et al. 1997. Salmonella shedding in racing sled dogs. Journal of Veterinary Diagnosis and Investigation, vol. 9, pp. 447-448.
Dogs can carry Salmonella without showing any signs of illness. In this study, Salmonella was found in the feces of 19 out of 30 sled dogs that were suffering from diarrhea, and from 18 out of 26 sled dogs that appeared perfectly healthy.

5. Koene, M.G.J., et al. 2004. Simultaneous presence of multiple Campylobacter species in dogs. Journal of Clinical Microbiology, vol. 42, no. 2, pp. 819-821.
Campylobacter jejuni, a human pathogen, was found in the feces of 12 dogs out of a group of thirty. Most of the 30 dogs showed no symptoms of infection.

6. Damborg, P., et al. 2004. Occurrence of Campylobacter jejuni in pets living with human patients infected with C. jejuni. Journal of Clinical Microbiology, vol. 42, no. 3, pp. 1363-1364.
Forty-five pet owners who were suffering from Campylobacter jejuni infection participated in a study of their pets. Eight of their pets - 4 dogs and 4 cats - were carriers of the same species of Campylobacter. In one case, the DNA fingerprint of the Campylobacter isolated from the human patient and the pet were identical.

7. Morse, E.V., et al. 1976. Canine salmonellosis: a review and report of dog to child transmission of Salmonella enteritidis. American Journal of Public Health, vol. 66, no. 1, pp. 82-84.
A dog became infected with Salmonella after drinking contaminated chicken broth, and experienced vomiting and diarrhea. A 16-month old child came into contact with the sick dog and developed a severe case of salmonellosis, requiring hospital treatment.


Reports such as these show conclusively that dogs and cats are able to carry and transmit harmful bacteria. Sometimes, the animals suffer from diarrhea or vomiting; sometimes, they show no apparent signs of illness. Either way, the Salmonella or Campylobacter that may be in your dog or cat’s feces or vomit can end up infecting you, a family member, or a friend.


Watch for Part 4 of this series, “What’s In It For Fido?”, which will appear on Saturday, March 15th.

It's A Dog's Breakfast - Part 2: Common Misconceptions

It’s time to set the record straight on some of the most common rationalizations used by people to justify the safety of feeding raw meat and poultry to their dogs.


Misconception #1. A dog’s stomach acid is stronger than a human’s. Therefore, all harmful bacteria will be killed in the dog’s stomach.

Stomach acid is an important defense against food-borne infection. The normal stomach pH* in humans while fasting (that is, with no food in the stomach) is approximately 2. Stomach pH rises (becomes less acid) for a period of time after a meal, because the stomach acid is diluted and buffered by food, then falls again.

The stomach’s digestive juices, which contain a combination of hydrochloric acid and the enzyme pepsin, will kill bacteria within 15 minutes when the pH in the stomach is lower (more acid) than 3. But if the pH rises above 4 for any reason, bacteria can survive – and even multiply – in the stomach.

The pH of digestive juices in the empty canine stomach – as in the human stomach – is approximately 2 at its most acid. As with humans, feeding alters the pH in a dog’s stomach, causing it to shift between strong acid and weak acid or even neutral conditions. But there is one difference.

In dogs, some of the contents of the small intestine are “burped” back into the empty stomach from time to time. This periodic “burp” raises the dog’s stomach pH to nearly 7 (the neutral point) – an ideal pH for bacteria to multiply.

Think about it. Dogs carry bacteria in their intestines, and dog poop is full of bacteria. There is only one way for bacteria to get into the intestines, and that is via the dog’s mouth and stomach.

*Acidity is measured by pH, which ranges over a scale of zero to 14, with zero being the most acid, 14 being the most alkaline, and 7 being exactly neutral.


Misconception #2. A dog’s intestinal tract is short. Stuff passes through too fast for bacteria to take hold.

The essential first step to infection - attachment to the cells that line the intestine wall - is very rapid. Salmonella and other pathogens can attach irreversibly to a susceptible cell immediately upon contact. It doesn’t matter how quickly the food passes through an animal’s intestine. Once attached to its target cell, the pathogen will stick like Krazy Glue and invade the cell at its leisure - usually, within one hour after adhering to the cell.


Misconception #3. A dog’s saliva contains lysozyme, an enzyme that destroys bacteria. Therefore, the bacteria get killed before they are swallowed.

Dog saliva and human saliva both contain lysozyme, an antibacterial enzyme, which is also present in some other body fluids, including tears.

Bacteria are divided into two major groupings – Gram-positive and Gram-negative – based on the chemical structure of their cell walls. Lysozyme destroys the cell walls of Gram-positive bacteria, but cannot harm Gram-negative bacteria, such as Salmonella, E. coli and Campylobacter.


Misconception #4. Dogs don’t get sick from bacteria and, therefore, can’t infect their human companions.

Dog may be less susceptible than humans to becoming sick from Salmonella, but they are not immune. And, just like Typhoid Mary, apparently healthy dogs can shed Salmonella in their feces. Furthermore, Salmonella isn’t the only pathogenic microbe that can infect dogs. Campylobacter, which is prevalent in raw poultry, can also be carried by dogs. Parasites such as Giardia can be spread from dogs to humans, too. I'll provide specific examples in Part 3 of this series.


Sorting through conflicting statements about health and safety issues can be both confusing and frustrating, especially when those statements are not backed up by independent scientific evidence. If you’d like to delve more deeply into the technical details, the links I’ve provided will give you a place to start.


Watch for Part 3 of this series, “Getting Down To Cases”, which will appear on Friday, March 14th.

It's A Dog's Breakfast - Part 1

The unprecedented 2007 pet food scandal sent a large number of dog owners on a search for a nutritious, safe alternative to dried or canned pet food. One option that many people investigated, and some people switched to, was a raw meat diet.

Feeding raw meat - either a commercial product or direct from the supermarket meat counter - has become increasingly popular in the last several years. Advocates of “raw feeding” claim that their pets are healthier, live longer, and are free from allergies and chronic diseases.

Poultry is a major component of most noncommercial raw food diets. Dogs are fed chicken wings, breasts, legs, backs and necks - all “on the bone”. Beef and lamb may also be part of a “raw meaty bone” diet, as is venison (especially in deer-hunting season) and other types of meat.

An indication of the increased popularity of raw meat pet diets is the availability of a very large selection of commercial “raw” products - typically in the form of frozen or freeze-dried patties. These are more convenient than do-it-yourself diets, and freeze-dried patties are much more practical when either boarding or traveling with a pet. There’s also comfort in feeding a commercial product - the feeling that the product is consistent in quality and is safe to use. After all, aren’t commercial pet foods regulated?

Unfortunately, in the United States, there are no regulations - other than the usual “truth in labeling” laws and the prohibition against knowingly selling adulterated products - that govern the safety of commercial raw pet foods. All that exists is Guideline #122, a Guidance Document issued in 2004 by the FDA’s Center for Veterinary Medicine (CVM). In this document, the FDA states that it “... does not believe raw meat foods for animals are consistent with the goal of protecting the public from significant health risks, particularly when such products are brought into the home and/or used to feed domestic pets."

The CVM hasn’t proposed a formal set of regulations to govern the safety and quality of commercial raw pet food. With just two people within CVM assigned to the entire pet food sector, the agency has neither the money nor the manpower to enforce any new mandates. But there is a much larger problem than the lack of FDA regulation of these products. Raw food diets, whether commercial or homemade, may make your pet and your family ill.

Watch for Part 2 of this series, “Common Misconceptions”, which will appear on Wednesday, March 12th.