Periodontal Disease:The Pet food Industry, Veterinary Profession and You.

Presentation to: 37th Annual Australian Veterinary Students Association Conference
University of Sydney
20th - 26th January 1996

Table of Contents


The Pet Food Industry

The Veterinary Profession
Suggested Further Reading


"If you are not part of the answer you are part of the problem" J.F.K.

The first rule of medicine entreats us to do no harm. How then can the veterinary profession be in such flagrant and persistent breach of the rule? Although the question seems simple enough the answer has many interdependent parts. As a starting point I believe that we could consider the impact of human nature and cultural conditioning on our conduct as veterinarians. To do the matter full justice we would need to explore biological, historical and psychological issues including the denial of common sense in favour of abstruse medical jargon. Unfortunately space and time do not allow and instead an examination of immediate issues will be undertaken. The role of the pet food industry will be considered alongside the veterinary profession. Periodontal disease aetiopathogenisis and sequelae will be reviewed with suggestions for your involvement in the big tasks ahead.

The Pet Food Industry


Prior to the the nineteenth century domestic dogs were fed left leftovers. In 1868 Jack Spratt invented the dog biscuit. In 1922 horse meat was canned for dogs 1. In the twentieth century technology made huge leaps putting American companies at the forefront of a world wide economic colonialist drive. In 1966 the giant Mars corporation opened its pet food business in Australia. Simultaneously they established Uncle Bens of Australia as the manufacturing division and a group known as Petcare Information and Advisory Service (PIAS). PIAS is euphemistically described as 'an autonomous, non commercial organisation committed to promoting socially responsible pet ownership.' According to the Australian consumers association magazine Choice (October 1995) the processed pet food market is now worth eight hundred million dollars annually. Uncle Bens controls more than sixty percent of the market. Friskies, a division of Nestlé, owns about twenty percent with the rest shared by a number of smaller companies several of which specifically target veterinarians.

Contents of the can

If one considers that, as a result of 4 billion years of evolution, whole raw carcasses should make up the bulk of a carnivorous diet then the manufacturers' offerings bear little resemblance. Their raw ingredients comprise offal, soya bean, a variety of grains and a series of artificial additives designed to overcome the most obvious shortcomings. After processing the mix is rendered physically and biochemically remote from the biological definition of what constitutes food for carnivores. Now our domestic carnivores are fed dry, semi moist, rolls, canned and more recently liquid concoctions. Some of the brands are promoted as adjunct feeds but the majority make grandiose claims to be complete and balanced. The implication being that anything else must necessarily be inferior and the user of the inferior products must therefore be less competent, intelligent, wealthy or simply inferior.

Examining the small print for disclaimers or words of modification indicating that the product is artificial or substitute food reveals no such admissions. On the contrary every implication is of a superior vitamin and mineral fortified formula promising miraculous nutritional value. The RSPCA when promoting its brand of processed pet foods squarely stakes its reputation on the contents of the packet.
"RSPCA pledge. The RSPCA monitors the processing of this pet food to ensure your pet's vitamin and mineral requirements are considered. Proceeds from sales are devoted to upgrading and expanding RSPCA shelters for dogs and cats. We pledge to help all creatures great and small - especially yours.Thank you for your support."
Underpinning the manufacturers' hype is the dependence upon two lists of nutrient profiles entitled NRC Nutrient Requirements of Dogs(1985) 2 and Nutrient Requirements of Cats (1986) 3. The authors make the surprising claim that, "Dogs/cats require specific nutrients, not specific feed stuffs." The list supplied, although supposedly complete and balanced, is frequently revised in the light of newly generated laboratory data. Unfortunately the eminent nutritionists engaged in this ongoing project have not considered how the whole raw natural food is completely altered both chemically and physically by their analytical process. As a further supposed validation of the nutrient profiles, diets are compounded according to the formula and fed to test animals. Compliance with The American Association of Feed Control Officials (AAFCO) trials is a boast printed on many pet food labels 4. In keeping with other aspects of the artificial pet food industry these claims do not stand up to scrutiny.

The AAFCO feeding trials require that eight animals be fed exclusively on the test diet for a period of six months. A principal criterion for success is that the animal should not lose weight over the period. Certain blood parameters need to fall within a given range. Unfortunately these tests are not carried out by independent scrutineers but instead they are performed in house by the pet food company. Adverse outcomes of a test would be most unlikely to be reported to AAFCO. For other reasons companies would be unlikely to wish to market products where consumption of the same resulted in early death. Non the less the AAFCO feeding trials allow that should two of the eight animals entering the test die during the six month period then the food may still meet the requirements. It should be born in mind that no control group of naturally fed animals are utilised in the test protocol. Judging by the number of foods claiming to be AAFCO approved, periodontal disease is not a disqualifying feature in the test system.

The $ maintains insidious control

With monopoly easy money the industry increases its strangle hold on the community. Despite the existence of strong laws regarding truth in advertising, labelling provisions, trade practices legislation and cruelty to animals acts the industry boldly promotes its wares. Wide media advertising and cunningly contrived advertorials compliment the label claims and point of sales marketing hype. Pet food companies target dog clubs and shows and have gained a favourable reception from some of the biggest animal welfare organisations. The World Wide Fund for Nature and Guide Dogs for the Blind receive hefty payments. As previously remarked the RSPCA now markets its own brand of pet foods. PIAS, the UBA offshoot targets schools, government departments and the AVA. Theirs is a subtle blend of pet care information and direct encouragement to feed more processed food and keep more pets.

The Veterinary Profession,

Living a lie

The companies have engaged in a cunning and successful strategy of manipulation. As with conventional colonialists they have simply paid or flattered the community leaders. In the case of pet health the community is led by the veterinary profession which in turn is led by the veterinary teachers and the AVA. From this position of dominance the pet food companies have been able to take almost complete possession of the thought processes of the veterinary profession. Veterinary research is often funded as are in kind donations to universities and veterinary schools. One company has a permanent student representative on the campus of each university. Veterinarians appear almost daily in advertisements on the television and in shows extolling the (supposed) benefits of processed foods. Whilst it is true many vets are unabashed at taking pet food company funds there are those who are careful not to disclose their source of funds or free air trips or hotel expenses, etc. Neither is there any legal requirement for them to do so. These same veterinarians, during the course of their teaching subtly overlook adverse pet food information, however relevant. In this as in any other area of legitimate concern what is not said is often as important as what is.

Individual veterinarians fall easy prey to the pet food dollar. Sometimes they perform for surprisingly small amounts of money seeming only to need the approval of the 'master'. This could be said of the AVA as an organisation which receives just a few thousand dollars but continues to promote the interests of the pet food industry in numerous ways. Despite diet being of consequence to one hundred percent of animals and periodontal disease affecting in excess of eighty five percent of animals over three years of age the AVA banned members from corresponding on these subjects through the AVA News. Meanwhile the AVA News continued to publish pet food advertisements and promotional pieces whilst lauding the benefits of the special relationship with the pet food sponsors.

A wolf in sheep's clothing-the AVA Pet PEP propaganda campaign

A deliberate strategy of the AVA in conjunction with PIAS is to disseminate, via the Pet PEP Programme, information in primary schools. Choice in the October 1994 edition advised consumers to adopt "a little healthy scepticism" regarding advice provided by vets. Their reasoning being that vets sell artificial pet foods, the AVA is heavily sponsored by the pet food industry and some officers work directly for the industry. It is hard for one to know how young consumers can be expected to exercise a little healthy scepticism if they are being carefully programmed as to how to think by these self interested organisations. Unfortunately teachers and State Education Departments do not realise how damaging processed pet foods can be. Neither do they realise that the AVA are acting as agents by proxy for the pet food industry.The upshot is that at the time of writing Pet PEP is being promoted in most Australian States.

Legal advice obtained in 1992 suggested that the profession in general and the AVA in particular are in likely breach of a number of statutes in respect to the sale of and or promotion of harmful artificial feedstuffs. All State Boards and Australian Veterinary schools have been provided with this information and the issue was raised during the recent AVA executive elections. In an attempt at getting the profession to confront its own apparent breaches of the Trades Practices Act 1974 a motion was put to the 1995 AGM. "That the AVA Executive be reminded that knowingly or recklessly disseminating false or misleading dietary information to primary school children via the AVA Pet PEP program is detrimental to the health of pet animals, the community and the AVA". A procedural motion "That this motion be not now put" was moved by Dr Plant (past president of the AVA) and as a consequence the important debate was aborted.

Changing the Understanding

Periodontal disease has been identified as a problem in domestic pets for at least seventy years. In recent times the major push to educate the profession commenced in December 1991. Breck Muir published a letter in the AVA News and a paper entitled Oral Disease in Cats and Dogs appeared in Control and Therapy. Robust correspondence ensued until March 1993 when the AVA banned further correspondence in the columns of the AVA News. "AVA News believes that this issue has been aired fully over the past year and does not intend to run further correspondence. -Ed." This directive carried an air of finality such that oral disease affecting greater than 85% and diet affecting 100% of animals was to be factored out of all further correspondence. Issues of AVA member rights, scientific curiosity and freedom of speech were all trammelled under this ruling.

In response a motion was put to the 1993 AGM seeking the establishment of a committee to look into aspects of diet and disease and for the termination of the literature ban. The AGM in a rare moment of independent thought voted against the wishes of the AVA executive. The correspondence ban was lifted and a committee was to be formed without any influence from protagonists or antagonists. In the event the AVA executive limited the investigation to the connection between periodontal disease and processed food. Despite the wishes of the AGM an employee of a large pet food company and a veterinary dentist with pet food industry sympathies both had major input into the workings of the committee.

With the admitted involvement of interested parties the committee reported that processed foods could be considered responsible for an increase in health of pet animals. No evidence was proffered in support of this assertion, only the statement that nutritional secondary hypoparathyroidism, hypovitaminosis A and thiamine deficiency had declined in recent years. Of greater significance was the welter of evidence presented to show that periodontal disease is unquestionably a product of soft/artificial diets 5. AVA News February 1994 carried the report: "further research is required to better define the relationship between particular diet types and oral health in dogs and cats. Those investigating small animal health problems should also take diet and diet consistency into account when researching systemic diseases - possible confounding effects of diet and poor oral health must be considered in such studies." Clearly this alludes to the fact that veterinarians have not previously taken diet and diet consistency into account. If this is the reality then modern veterinary research and practice would appear to have proceeded without control groups of normal animals. Biological information derived without reference to normal controls must be treated as tentative and unreliable.

A profession genuinely interested in self preservation and responsiveness to the needs of the community would be expected to take these matters seriously. In the case of the AVA the $7000 report and its implications have been shelved without comment. In a show of unity with the executive the 1994 and 1995 AGMs voted neither to obtain more information nor disseminate that information for the benefit of the public. This idiosyncratic approach appears curiously at odds with the current trend in human medicine the natural sciences where basic tenets and practices are being reexamined.

Periodontal Disease, The Process

Heat treated processed foods may contain the same chemical elements but they are completely dissimilar to the intricate biochemical make up of the natural raw diet. Diseases of straight forward chemical excess or deficiency are compounded by problems of direct toxicity or microbial overgrowth producing indirect toxicity within the bowel lumen. Unravelling the complex chemical interactions within the body is exceptionally difficult and perhaps impossible without the aid of natural food fed controls.

Periodontal disease does not arise as a result of chemical imbalances but derives from the lack of cleaning and physical stimulation of the oral cavity. Periodontal disease is described by Harvey and Emily as; "periodontal disease is caused by accumulation of bacterial plaque on the teeth and their supporting structures. Periodontal disease includes gingivitis (inflammation confined to the gingival soft tissues) and periodontitis (the more severe form in which bone supporting the tooth is lost, with eventual loss of the tooth). It is a progressive, usually non regenerative and incurable disease if plaque is not controlled, but it is preventable and manageable with proper treatment techniques."6.

Plaque organisms number in excess of three hundred different species and one cubic millimetre contains three hundred million bacteria 7. The microbial ecosystem within the oral cavity is highly evolved and both creates and depends on the micro environmental conditions. Consequently many oral bacteria cannot be grown in vitro. The microbes exert their direct destructive action upon the periodontium in a number of chemically induced ways. These include the production of exotoxins, endotoxins, proteases, fibroblastic cytotoxins, potent lymphocyte mitogens, chemotactic inhibitors and other damaging metabolites. In response the hosts immune system becomes activated producing cellular changes involving neutrophils and lymphocytes. Lysosomal enzymes are released by the damaged cells including elastases, hyaluronidase, collagenases, lympokines and prostaglandins 8. This is a perpetual process associated with pain, inflammation and suppuration leading to destruction of the supporting tissues of the teeth with eventual disease and loss of bone and teeth.

In domestic carnivores, known for their ability to disguise signs and corresponding inability to speak about symptoms, we need to look carefully for outward indicators of disease. An offensive odour is often times the first and persistent noticeable effect. Carnivores frequently resist being examined in and around the mouth and so subtle changes in gum colour and thickness are easily overlooked. With the aid of general anaesthesia a more thorough assessment can be made but even then a full appreciation is difficult to obtain. In human periodontal disease assessment gingival probing, radiography, subtle temperature differential detection and a host of serological tests can be employed but none with dependable accuracy. In veterinary medicine oral disease is frequently in an advanced state before detection occurs.

A range of diseases (bacterial endocarditis, glomerulo nephritis, polyarthritis, polyvasculitis, leucopenia 9.) have now been shown to be associated with the persistent toxic and microbial challenge of periodontal disease. Some authors acknowledge the association of periodontal disease with organ dysfunction in geriatric animals but, appear to disregard the early consequences in juveniles. Based on my experiences in clinical practice and observation of the natural world it is my belief that periodontal organisms exert a profound and continuing influence from the time of deciduous tooth eruption 10.


The cure and prevention of periodontal disease

Under the present conditions humble butchers cure and prevent more periodontal and associated disease than a host of veterinarians. The leaders of our profession have ignored this situation and have continued to inculcate veterinary students with an outmoded set of beliefs. A number of possible outcomes can ensue and whether good or bad will mostly fall upon the coming generations of veterinarians.

You cannot rely upon your teachers to steer you from danger towards positions of advantage. You must rely upon and inform yourselves to the best of your abilities.

In this way you may gain influence over your teachers and rescue the good name of the veterinary profession. Your future as veterinarians and the carnivores in your care depends upon the cure and prevention of periodontal disease.


1. Kronfeld D.S. (1983) Commercial pet foods. Proceedings 63 Nutrition. Post Graduate Committee in Veterinary Science, University of Sydney. Sydney pp225-230

2. Nutrient Requirements of Dogs (1985) Formulated diets for dogs. National Academy Press. Washington pp42-43

3. Nutrient Requirements of Cats (1986) Formulated diets for cats. National Academy Press. Washington pp30-33

4. AAFCO Yearbook (1993) Pet food committee report. Association of American Feed Control Officials. Atlanta pp280-302

5. Watson, A.D.J. (1994) Diet and periodontal disease in dogs and cats, Australian Veterinary Journal, 7:313-318

6. Harvey, C. E. & Emily P.P. (1993) Periodontal Disease, Small Animal Dentistry, Mosby, St Louis, 89

7. West-Hyde L., Floyd M. (1994) Dentistry. Textbook of Veterinary Internal Medicine, Fourth edition. W. B. Saunders, Philadelphia.

8. Liebana, J & Castillo, A. (1994) Physiopathology of primary periodontitis associated with plaque. Microbial and host factors, A review. Parts 1 and 2. Australian Dental Journal, 39:228-232 & 310:315

9. Lonsdale T. (1995) Periodontal disease and leucopenia. Journal of Small Animal Practice 36, 542-546

10. Lonsdale, T. (1993) Cybernetic Hypothesis of Periodontal Disease in Mammalian Carnivores,Journal of Veterinary Dentistry, 11:1, 5-8

Suggested further reading

Billinghurst I.,(1993) Give Your Dog A Bone., I Billinghurst, Lithgow NSW Australia

Lonsdale, T.(1993) Preventative Dentistry, Veterinary Dentistry, Post Graduate Committee in Veterinary Science, University of Sydney, Sydney, Proceedings 212:235-244