Periodontal Disease:The Pet
food Industry, Veterinary Profession and You.
Annual Australian Veterinary Students Association Conference
University of Sydney
20th - 26th January 1996
Table of Contents
"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.
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.
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
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.
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
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
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
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
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
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