Dental Chews

Introduction

The act of chewing itself produces more saliva and physically helps to reduce plaque accumulation. Salivary flow also contributes to protection of the oral cavity and teeth by bathing all oral structures and washing bacteria away. Saliva contains numerous antibacterial substances which contribute to the defense mechanism in the mouth, but also contains products like lactoferrin which binds to iron, a mineral needed for bacterial growth. Other enzymes present in saliva help neutralize potentially harmful by-products released by bacteria.

Cats

Many cats will not chew or spend a long time chewing. Cats tend to tear food into smaller pieces rather than spending a long time chewing and grinding the food. Finding a product that creates a good chewing action in cats, whilst maintaining their interest is not easy. At this time there are fewer products on the market for cats than for dogs to aid chewing.

Dogs

Certain dog chew treats have been shown to have a beneficial effect in reducing plaque and calculus and are recommended as part of a daily oral care program. Always check the scientific evidence for any claim on a commercial diet ensuring that the claim is relevant for the target species as well as having published clinical trials in peer reviewed journals.

The shape and design of the chew helps reduce the build-up of plaque on the tooth surface by its mechanical action. The shape is often chosen to maximize contact with the crown of the tooth, for example an x-shape. A more unique design of a chew recently launched has a spongy loofa texture allowing the tooth to penetrate right into the chew without the chew breaking. This has been shown to be very effective in removing plaque at the gingival margin, and in so doing having a direct effect on maintaining healthy gums and reducing gingivitis.

Chews may also contain additives to help reduce plaque and calculus. Two active ingredients present in some chews are sodium tripolyphosphate and zinc sulphate which bond with calcium in saliva and thus reduce the calculus build up by reducing the calcium availability.

Other active ingredients are added to chews to help freshen breath. For example, a blend of green tea extract and eucalyptus oil freshens breath by reducing bacteria that cause halitosis. Volatile Sulphur Compounds (VSCs) are produced by bacteria in dogs’ mouths and are the cause of halitosis but have also been shown to be directly linked to periodontal disease and its destructive processes.

All dental chews are different and not all chews have the same properties or qualities of others. Whenever deciding on what chew to recommend for passive oral homecare ensure that any additives are not harmful, and are beneficial and the product design is correct for what it should achieve.

Some chews available are too hard and may result in tooth fracture despite being marketed as having a dental benefit. Examples would include all natural bones, whether processed or fresh from the butcher and dried cow hooves. Hard-pressed rawhide bones, or knotted rawhide, and nylon bones are too hard and may cause dental fracture. The general rule of thumb is that the product should be pliable and not as strong as the tooth enamel in order to prevent fractured teeth.

Pig’s ears are available at many pet stores and markets. They are basically just pig skin and cartilage, often dried and smoked to prevent decay. They have a mild abrasive effect on the tooth surfaces without great risk of being too abrasive. The thin and flexible nature of pig’s ears makes them very unlikely to cause dental fractures. Some dogs tolerate these very well, while others may experience digestive upset. As the ears are sold from bulk bins generically, there is no assurance of quality control and there have been reports that they may harbour bacterial pathogens such as Salmonella. If a large chunk of an ear is swallowed, it will likely be broken down by gastric juices and pass without incident. However, choking and oesophageal blockage are possible. Rawhide strips are a consumable treat that many dogs really love, however as they provide non-digestible protein, they do not add greatly to the caloric intake. Use thin strips as this makes it very unlikely that any teeth will be damaged whilst the dog is chewing. The abrasive action of chewing the rawhide does help reduce plaque, calculus and gingivitis. Once again, quality control varies and some raw hide has been shown to be contaminated with pathogens for example Salmonella.