Dry Pet Food and Dental Disease in Dogs and Cats

One of the most common diseases in cats and dogs that I see in practice is dental disease. According to the American Veterinary Dental Society, by three years of age 70-80% of dogs and cats will have signs of oral disease. Unfortunately,  many people think that dental disease is only cosmetic or not a real health problem for dogs and cats. However, in humans it is clear that poor oral health is not only a source of discomfort but a significant risk for other serious diseases. While there is little research on the subject, there is no reason to believe that the same is not true for dogs and cats. There is certainly no question that oral disease is a source of real suffering for our pets.

Unlike humans, dogs and cats rarely get cavities. This is probably due to differences between the bacterial flora that normal inhabits human mouths and that which lives in the dog and cat mouth. Genetics also likely plays a significant role, as this is one of the most important determinants of susceptibility to dental disease in humans. Most dental disease in dogs and cats is periodontal disease, inflammation of the gums and the tissues that hold the teeth in the jaw. Periodontal disease is responsible for pain, trouble eating, tooth loss, and potentially diseases in other organs.

Periodontal disease begins with the accumulation of plaque, a biofilm containing proteins and oral bacteria. Plaque, and the subsequent mineralized material known as calculus or tartar, initiates a cycle of inflammation in the periodontal tissues which can ultimately lead to severe pain, swelling, and tooth loss. Periodontal disease can be treated, but this requires general anesthesia and often involves extraction of diseased teeth, so of course prevention is preferred to treatment whenever possible.

While genetic factors are significant in determining if an individual is likely to develop periodontal disease, these are not readily controlled, so the focus of preventing periodontal disease is primarily on reducing plaque and calculus accumulation and maintaining healthy periodontal tissues. The most effective method for preventing periodontal disease is regular, proper home care. Brushing, in particular, is a great way to remove plaque and prevent oral disease, and many dogs and cats will tolerate it well if it is introduced when they are young.

In addition to brushing, and especially for those pets that do not tolerate it, there are innumerable products marketed for preventing periodontal disease. Most of these have little to no supporting evidence for their claims. Whenever considering using one of these products, it is useful to look for the Veterinary Oral Health Council (VOHC) seal of approval. The VOHC is an independent organization which requires reasonably rigorous, scientific evidence demonstrating efficacy in preventing plaque (which is most important) and calculus accumulation (which is somewhat less useful in preventing periodontal disease) in order to obtain their seal. Such products, including oral rinses and gels, treats, and chews, are not a substitute for brushing or regular veterinary prevention and treatment measures. But there is good reason to believe that if they have obtained VOHC approval then they have some value.

One of the most common actions recommended, by veterinarians and others, to minimize the development of oral disease is feeding dry commercial pet diets. It is often argued that chewing on kibble cleans the teeth and slows the development of periodontal disease. However, there is some reason to doubt this claim. Most dry diets made for dogs and cats do not require chewing, and the kibble is often swallowed whole. And typical kibble is very easily broken apart, so it does not seem likely that it is very effective in cleaning teeth, especially under the gum line, where  plaque and calculus cause the most inflammation and disease. And at least one study looking at the effect of diet and chewing materials on oral health did not find that feeding a dry diet only was associated with any less periodontal disease than other feeding methods.

Of course, there is also no evidence that dry diets are a significant cause of dental disease, as is often alleged by proponents of other feeding methods, and there is no evidence to support claims that feeding canned, homemade, or raw diets is better for oral health. And while there is some evidence that bones, like any abrasive chewing material, can help clean teeth, the many risks of bones, including fractured teeth and potentially life-threatening injuries to the gastrointestinal tract, likely outweigh any benefits. So while dry diets in general may not be of benefits in terms of preventing periodontal disease, this does not automatically mean that the alternatives to commercial dry foods are any better.

In fact, a new study suggests that the opposite might be true, and that dry commercial diets may have some value in preventing dental disease after all.

Catherine Buckley, Alison Colyer, Michal Skrzywanek, Katarzyna Jodkowska, Grzegorz Kurski, Jerzy Gawor, Michal Ceregrzyn.. The impact of home-prepared diets and home oral hygiene on oral health in cats and dogs. British Journal of Nutrition (2011), 106: S124-S127.

This survey of thousands of dogs and cats seen by veterinarians in Poland identified brushing and the use of dental treats as significant factors reducing the risk of oral disease. No surprise there. However, the results also showed that homemade diets were associated with an increased risk of oral disease and that exclusive feeding of dry diets reduced the risk of oral disease.

The present study aimed to elucidate the influence of feeding home-prepared (HP) food v. commercial pet food on oral health parameters in these animals and to investigate the effect of home oral hygiene on oral health. The study surveyed 17 184 dogs and 6371 cats visiting over 700 Polish veterinary surgeries in 2006–7 during a Pet Smile activity organised by the Polish Small Animal Veterinary Association. All animals underwent conscious examinations to assess dental deposits, size of mandibular lymph nodes and gingival health. An oral health index (OHI) ranging from 0 to 8 was calculated for each animal by combining examination scores, where 0 indicates good oral health and 8 indicates poorest oral health. Information was collected on age, diet and home oral hygiene regimens. There was a significant effect of diet on the OHI (P < 0·001) whereby feeding the HP diet increased the probability of an oral health problem in both cats and dogs. There was a significant beneficial effect of feeding only commercial pet food compared with the HP diet when at least part of the diet was composed of dry pet food. Daily tooth brushing or the offering of daily dental treats were both effective in significantly reducing the OHI in both cats and dogs compared with those receiving sporadic or no home oral hygiene. Feeding only a dry diet was beneficial for oral health in cats and dogs. Tooth brushing and the offering of dental treats were very effective in maintaining oral health, provided they were practised daily.

Obviously, this is only a single study, and it is impossible to evaluate the methodological quality of it from the abstract alone. Many details, such as what kind of homemade diets were included and whether there might be differences among them, are not. However, it does provide at least a bit of evidence against the often made claim that dry diets have no value in preventing dental disease or that homemade diets, such as raw or BARF diets, are superior.

There are undoubtedly many good reasons to consider alternatives to feeding only commercial dry diets. Specific medical conditions may require diets of a composition or consistency other that dry kibble. And while much of the propaganda about the health risks of commercial dry diets for cats is irrational and not supported by evidence (e.g. 1, 2), there is some reason to believe that moist diets may be superior for cats in some respects. So this study is by no means a reason to recommend feeding exclusively dry commercial diets. The overall nutritional needs of each individual must be assessed, not simply the question of dental disease.

However, for those patients, especially small breed dogs, at high risk for severe dental disease, it is important to consider the potential value of commercial dry diets in preventing the significant health risk. Diets that have obtained the VOHC seal for plaque prevention, in particular, should be considered a legitimate tool in the management of periodontal disease, and the overall health and well-being, of individual patients.

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19 Responses to Dry Pet Food and Dental Disease in Dogs and Cats

  1. Art says:

    The pet toothbrushing data I have seen years ago show a 3 percent compliance rate among clients 5 percent among vets. There is a vohc seal of approval for one drinking water additive and I wonder if it is similar to the new human dental additive for tarter and gingivitis called cpc. To add confusion about the need for sedation or anesthesia the majority of vets i know of just lately non offer awake dental cleanings in south fla. Some who do awake dentals promote they can do periodontal treatments awake. I have not found a vet school that does awake dentals or data to know how often dogs bite during the awake dentals.
    Art Malernee dvm
    Fla lic 1820

  2. Art says:

    Should read “now offer” not “non offer”. I could copy and paste a medical release form that vets in south fla have the client sign before doing awake dentals if anyone wants to see them. Since dentals are shopped for items and vets promoting dental cleanings are not required to have dental xray machines in their offices like human dentist the issue of awake dental cleanings is dividing. I do not know of any boarded vet dentist doing them but they have dental xray machines and want to take dental xays. One boarded pet dentist got up in front of the fla vet board to request anyone advertising dental cleanings have a dental xray machine. I would support that proposal but less than 10 percent of the vets I know now have dental xray machines.

  3. skeptvet says:

    We have several full-time dental technicians, one of whom is working towards her certification in veterinary dentistry, and we have a boarded dentist who sees patients at our practice once a week. It seems pretty cear that accurate diagnosis of the degree of periodontal disease, retained roots, periapical abcesses, and other relevant pathology requires taking x-rays. And the kind of work we routinely do, such as root planing and packing of periodontal pockets, cannot b done awake. So i think the case against non-anesthetic dentistry is pretty clear. Perhaps one could make an argument that an incomplete cleaning is better than no cleaning at all if clients are unable or unwilling to have a thorough dentistry done under anesthesia, but I don’t think the two procedures are at all equivalent.

  4. Art says:

    If the dog will co- operate I think you could do a root canal with a local. I think that’s the thing that has got everyone offering awake dentals. If you do not offer them people call other vets shopping and awake dentals are offered by most vets now. I do what is called deep cleanings in human medicine. My own dentist did a deep cleaning on one side of one tooth with out drugs. So it can be done if you will accept the pain. Here is a concent form posted on a vets website.

  5. Art says:

    Best I could get iPad to do was copy link to awake dental consent form


    Art Malernee dvm
    Fla lic 1820

  6. v.t. says:

    “Awake”-dentals are crazy. Without xrays and exploration, you’re missing the entire picture. Those vets performing awake-dentals aren’t following code of ethics in my opinion. How many disease factors and underlying factors are missed until one sees under the gumline, under the tooth, the root, etc!

    We’re already fighting the commercial “non-anesthetic” dentals performed by laypersons in the pet shops, grooming facilities, etc. Maybe in large part, we have them to thank for, for convincing pet owners their pets don’t need veterinary oral care.

    The only reason(s) I personally feel an awake “cleaning” could or should be done is if the pet is not an anesthesia candidate, has underlying renal, liver or heart disease that would be compromised under anesthesia, etc. (to address an abscess or help decrease painful inflammation in order to keep the pet’s appetite sufficient etc)

    Perhaps keeping the cost of a dental would help clients get their pets’ oral health under control. A $250.00-300.00 charge for one extraction, for example, is just one area that turns pet owners off; or the itemized charges like anesthesia/pain med injections/topicals/blood work/xrays/extractions/polishing/cleaning, etc that add up quickly – in this economy, who can afford that, particularly with multi-pet households. 10% off in February? (dental month) – make it 15% or slightly more, and you might get more clients more focused on prevention. The dental posters in the exam room obviously aren’t cutting it, pet owners need real education/warnings from the vets during EVERY exam.

  7. art malernee dvm says:

    “Awake”-dentals are crazy. Without xrays and exploration, you’re missing the entire picture. Those vets performing awake-dentals aren’t following code of ethics >>>>

    Here is a prospective unpublished awake dental study done by the boarded dental vet in my area that wants the fla vet board to require dental xray machines if you advertise dentals in florida. I am not sure why the study never got published.
    About two years ago out of curiosity and to try to prove in the literature that non-anesthetic dentistries fail on every level, I conducted a study at our office– 30 dogs and cats (combined) first cleaned by a non-anesthestic technician from a company that is in our area immediately followed by an anesthetic oral hygiene visit performed by our staff with dental films. The clients were informed that both procedures would be performed.

    The non- anesthetic dental technician ( flown in from California ) sat cross legged on the floor with the dog or cat in his lap and gently he used a curette to hand clean the crowns he could get to, and then used a mechanical polisher. He also charted with a dental probe.

    The study was set up to show what they found vs. what we found plus what they left behind. Unfortunately because there was not a third independent party it became an us vs. them exercise where we found significant pathology they did not plus subgingival plaque and calculus. Not sure if it will ever be published but it was educational.

    In the end I was amazed how well their technician controlled the patient– even cats.

    Jan Bellows, Dipl. AVDC, Dipl. ABVP

  8. v.t. says:

    Maybe taking at least 5 readings of BP/pulse and heartrate would paint a different picture.

    Not to mention, cats are good at hiding pain, whether restrained or not.

    I think it’s asking for trouble to do non-anesthetic dentals. Period. The anecdote reference above means nothing. It would be interesting to see what the “tech” missed. Let’s not mention the fact the poor pets were put through an unnecessary procedure (that by all accounts could have been painful and/or harmful).

  9. art malernee dvm says:

    I have ask a vet friend who has awake dentals done in the office what percent of the pets will allow them to do it and the reply I got was less than ten percent but that is not supported by dr bellows amazed comment. The ultrasonic dental tip when it touched my root on one side of my tooth hurt me. If I had needed my entire mouth deep cleaned I would have wanted drugs. With no prospective studies to support i am reluctant to tell clients they should not have awake dentals. I do think all dentals awake or druged using ultrasound or scalers should be done by someone who has a licence to do them. Sad to say in florida most dentals done in vet hospitals are done not by the licensed vet but by their unlicensed employees. The person cleaning your teeth in florida has a licence to do so but not for pets in the state of florida except for the few licensed vets who do not have their employees do the dental. If the people doing dentals in our offices do not need a licence its difficult to say the groomers cannot do them.
    art malernee dvm

  10. rita says:

    Don’t suppose there are any studies done on feral dogs?

  11. rita says:

    The state of their teeth.

  12. skeptvet says:

    There is one study that looked specifically at oral disease in African Wild Dogs and found that there was no evidence that their natural diet prevented the occurrence of the same kinds of disease seen in domestic dogs:

    Steenkamp, G. Gorrel, C. Oral and dental conditions in adult Afircan Wild Dogs skulls: A preliminary reportJ Vet Dent. 1999 Jun;16(2):65-8.

  13. art malernee dvm says:

    Steenkamp, G. Gorrel, C. Oral and dental conditions in adult Afircan Wild Dogs skulls: A preliminary reportJ Vet Dent. 1999 Jun;16(2):65-8.>>>>

    good find.

    I have a memory that cat absorptive lesions were not found in museum cat skulls from the ninetieth century that would ad some support to the hypervit d theory some still think is a factor in cat absorptive lesions.

    art malernee dvm

  14. rita says:

    Interesting, thanks for the ref.

  15. Aleja says:

    Interesting – I hadn’t heard of vit d being a potential factor in reabsorption in cats. I have a 13 year old Siamese who has had a bad mouth most of his life despite routine oral care and will soon have to get his teeth yanked. He recently was found to have a very low b12 level and thought to have IBD given his other symptoms, yet we’ve been remarkably successful in reducing his GI issues with a diet change. His littermate has
    always had good teeth, however, but unfortunately suffers from asthma and is on Flovent.

  16. Amy says:

    The naturalistic argument fails to consider longevity in feral or long-deceased animals. Natural selection requires an animal to live only long enough to have one litter to pass on their DNA. In order for any comparisons to be valid, wouldn’t they have to be matched for age? How many museum cats were over 10 years old at the time of their demise? How long do feral dogs survive in the wild? Wouldn’t they succomb to infectious disease long before developing gingivitis?

  17. skeptvet says:

    Yes, making comparisons between wild and captive or domesticated animals and then drawing conclusions about the factors that account for differences seen, and what they mean for husbandry, is a highly problematic enterprise. It is easy to bias such comparisons to support a pre-existing opinion.

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