Canine Dental Health
Owners will generally be prompted to seek advice about their pets’ teeth due to socially unacceptable breath, however, periodontal disease carries far more significant implications, both locally within the oral cavity and with the potential for systemic effects. Though veterinary practices are increasingly acknowledging the importance of dental disease and equipping themselves more effectively to perform routine dentistry, the integral role that homecare should provide in both prevention and maintenance of oral health following a dental procedure is often understated. This article aims to discuss normal tooth anatomy, the development of periodontal disease and focus on preventative homecare options.
Normal Dental Development and Anatomy
Puppies initially develop their primary, or deciduous, dentition between the ages of 3-6 weeks. At 3 months of age, the permanent (adult) teeth begin to erupt and the deciduous teeth are shed. By 6-8 months of age, most dogs will have their full set of adult teeth, 42 in total.
Normal tooth anatomy is demonstrated in Fig 1.; the crown of the tooth is the portion that is visible above the gingiva (gum) and the root of the tooth is the portion existing below the gum line, encased in the jaw bone. The crown of the tooth is covered in a very hard enamel layer; directly below this is dentine which is the main supporting structure of the tooth. The periodontal ligament anchors the tooth root to the alveolar bone. The pulp cavity is the living tissue of the tooth, comprising of blood vessels, nerves, lymphatics and connective tissue.
Development of Dental Disease
In terms of gingivitis and periodontal disease, plaque is the source of all evil as it is the cause of both of these conditions. It is a soft, sticky, tooth-coloured paste-like mixture of salivary glycoproteins, sloughed epithelial cells, white blood cells and bacteria, which is tooth coloured and therefore only clearly visible when stained with a discloser.
Within hours of eating dental surfaces become coated in a layer of glycoproteins which are then colonised by bacteria. As this immature plaque matures it becomes more organised and firmly adhered to the teeth. Mature plaque consists of 75% structural matrix and 25% bacteria and it is only as it matures that it becomes more harmful. Plaque builds on all surfaces in the mouth but more so on teeth as they have a static surface. Plaque bacteria produce various products but two of the most significant groups are volatile sulphides that cause bad breath (halitosis) and toxins which cause tissue inflammation. Plaque is the precursor to tartar (calculus) and tartar always has plaque on and in its surface.
Just as in human dentistry, the regular removal of plaque, particularly from the gingival sulcus, is central to the control of gingivitis and periodontal disease. If plaque is not removed from the teeth, ongoing tissue inflammation and irritation results which begins to affect the gingival attachment to the tooth and formation of a periodontal pocket at the gingival sulcus. As dental disease progresses, ultimately the bone support and gum attachment for the tooth is lost, with high levels of sub-gingival infection present. This development of dental disease may be graded from 1 to 4 in terms of severity, which is a representation of tooth structures affected, degree of reversibility and level of intervention required. Grade 1 is the mildest level of dental disease and represents gingivitis only, with no loss of gum attachment. At this stage, it is completely reversible with good home care. Grade 4 represents the most severe level, with deep periodontal pockets and advanced loss of bone support and gum attachment. The later in the course of dental disease that intervention is attempted the more aggressive therapy has to be and the poorer the prognosis. Damage to the periodontal ligament is irreversible and once this has occurred, the objective is to halt or slow down the progression of disease in order to conserve the teeth. Periodontal disease is self-perpetuating as the deeper the periodontal pocket the greater the amount of plaque that will be deposited sub-gingivally. As a consequence of these greater levels of plaque, diseased teeth are also associated with higher levels of bacteria.
As previously mentioned, halitosis is one of the commonest reasons an owner may seek veterinary advice regarding dental health, even if the other disease processes progressing in their pets’ mouth have gone unnoticed. It is also important to note that dental disease can be a source of chronic pain, resulting in behaviour modification that is only identified once that pain is removed and the positive change in the pets’ demeanour is noted by the owner.
Homecare
With the importance of dental health highlighted throughout this article, it should be clear that on-going dental hygiene is vital to maintain a healthy mouth, however, it also needs to be regarded as an integral part of any dental procedure carried out at a veterinary practice to maintain the benefits provided by the intervention. There are a number of options available for dental homecare and time must be taken to assess which will be most suitable for both the client and the patient, in order to maximise compliance.
Tooth brushing is the gold standard of dental care; the abrasion provided by brushing provides physical removal of plaque and a veterinary formulated toothpaste can aid in inhibiting plaque bacteria. Only those toothpastes specifically designed for animals should be used as human toothpastes are not designed to be swallowed and can cause problems due to their high fluoride content and frothing agents. Pet toothpastes will also improve compliance as they are designed to be palatable, which can increase acceptance. Ideally, tooth brushing should be introduced when the animal is still young, but even adult dogs can be taught to accept this as part of their daily routine as long as the introduction is gradual with positive reinforcement.
Despite being the best method for home care oral health, tooth brushing may not be possible for some owners or some pets, therefore it is important to offer other alternatives in these situations. Chlorhexidine gluconate rinses can be used as either an adjunct or alternative to brushing; these are very broad spectrum antiseptics and can inhibit the development of plaque. One application can be effective for up to 12 hours so twice daily use is ideal, and they are helpful for animals that will tolerate oral application of a rinse but not a tooth brush. Again, it is important to use only veterinary specific rinses as human preparations often contain alcohol. Oral rinses, which can easily be added to drinking water also provide a less intrusive option for owners whose pets don’t tolerate brushing.
Dental chews are a third option for owners and these are the easiest method of introducing oral homecare. The design of the chew is important, both in shape and consistency; ideally they should conform to tooth shape when bitten into to improve effectiveness. Though these options represent a low maintenance way of providing dental homecare, owner expectations should be realistic; these will never be as effective as brushing as they cannot remove plaque from the gingival sulcus, which is the site of the main disease processes. Considerations also need to be made with regards to the patients’ preferences; if the dog doesn’t like to chew very much, this will limit the effectiveness further. Ideally, these options should be seen as adjuncts to tooth brushing or chlorhexidine rinses, or as a ‘fall-back’ option where these have not been possible to instigate.
In conclusion, dental disease represents a significant health and welfare consideration in pets but with the correct education and advice, owners are able to contribute greatly in maintaining the oral health of their dog and significantly reduce the development of dental disease. In cases where veterinary dental intervention has been necessary, it is also vital that on-going homecare is seen as essential rather than optional, in order to maintain the benefit achieved following dental procedures.
References:
1. Hamp S E et al (1984). A macroscopic and radiologic investigation of dental diseases of the dog, Veterinary Radiology 25: 86-92.
2. Kortegaard H A, Erikksen T and Baelum V (2008). Periodontal disease in research beagle dogs – an epidemiological study, Journal of Small Animal Practice 49: 610-616.