WO2002078462A1

WO2002078462A1 - Methods and products for removing tartar from the teeth of a pet

Info

Publication number: WO2002078462A1
Application number: PCT/EP2002/003512
Authority: WO
Inventors: John Russell-Maynard
Original assignee: Societe Des Produits Nestle S.A.
Priority date: 2001-03-30
Filing date: 2002-03-25
Publication date: 2002-10-10
Also published as: AU2002302478A1; WO2002078462B1

Abstract

Products and methods for maintaining or improving the dental hygiene of a pet are provided. The product includes an effective amount of a tartar softening agent. The agent may be contained in a chewable structure that may be administered to the pet as a treat or as a portion of a meal.

Description

"METHODS AND PRODUCTS FOR REMOVING TARTAR FROM THE

TEETH OF A PET"

BACKGROUND OF THE INVENTION The present invention generally relates to dental hygiene. More specifically, the present invention relates to improving the dental hygiene of pets.

It is of course known that there are many different products for improving the health and well-being of animals, especially pets. These products run a vast array including products designed to improve dental hygiene i pets.

It is known that poor dental health is very common in animals, including pets such as dogs and cats. Poor dental hygiene can result in periodontal disease. Periodontal disease is one of the most commonly treated diseases by veterinarians in the Unit d States.

.e lonj., urn impact of poor dental health can be devastating to an animal.

Poor dental health is thought to be a contributing factor in the death of dogs, cats, and other mammals. In pets, it has been linked with serious diseases of the heart, liver, kidney, and other internal organs. Indeed, one study demonstrated that every dog with periodontal disease had pathological changes in the heart, liver, and kidneys.

Most periodontal disease starts with the formation of a film of a soft amorphous material called plaque, consisting primarily of oral bacteria, bacterial byproducts and oral debris. This film typically covers both the exposed tooth surface and the area lying under the gum line, the gingival cavity. Through the deposition of calcium and othei mineral salts, this layer hardens and develops into tartar. Although tartar is hard, it is also porous and adheres to the tooth surface. It appears to be progressively deposited in layers and provides a rough surface onto which more plaque is deposited. As tartar builds up, a broad range of microbes can attach. The byproducts of metabolism from these bacteria cause inflammation of local tissues including those surrounding the gingival cavity. This ultimately leads to periodontal disease. The earliest stage is gingivitis, characterized by inflammation of the gums. As periodontal disease progresses, gingivitis becomes periodontitis, with inflammation extending into the connective tissues surrounding the tooth. Through gingivitis and periodontitis, it is thought that harmful bacteria enter into the blood stream and ultimately lodge in the heart and other internal organs.

It has been found that the sides of the teeth facing the cheeks, i.e. located in the buccal cavity, have a greater incidence of gingivitis and plaque/tartar build-up than the sides of the teeth facing the tongue, i.e. the lingual side. It has also been found that the rear teeth, i.e. the pre-molars and_. molars, more rapidly develop plaque and tartar than the front teeth.

A variety of different development efforts have focused on cleaning teeth and improving dental hygiene in animals. One simple method is to initially have a veterinarian remove existing tartar by complete dental prophylaxis (ultrasonic cleaning and polishing) and have the owners regularly brush their pets teeth thus stopping plaque build-up and tartar formation. Unfortunately, few pet owners are willing or able to maintain this level of veterinarian or home care. Another option is to provide pets with products that can clean while being chewed and there are a number of such products that claim to help clean pets teeth. In United States patent number US5,407,661 there is disclosed a dental product comprising a biscuit treat item having a cellular matrix and containing abrasive fibres as well as a pyrophosphate salt as a tartar control oral care additive in the matrix. The tartar control additive is incorporated in these chew products at a concentration effective to inhibit tartar formation on the animal's teeth.

Although US Patents 5,000,940 and 5,000,943 propose baked dog biscuits that contain an inorganic pyrophosphate salt to cause a reduction in tartar accumulations on their teeth when chewed by dogs, they do not propose a solution to the problem of removing tartar after it has already formed.

Again these initially rely on the owners having the existing tartar removed by a veterinarian through complete dental prophylaxis. They function by the chewing action causing the product to abrade the tooth surface thus dislodging the plaque and reducing its build-up. Some even incorporate chemicals to try and inhibit the formation of tartar. Few are totally effective.

Moreover, all suffer from the disadvantage that none help remove existing tartar and all rely on owners regularly visiting veterinarians to have tartar removed, which few pet owners are willing or able to do on a regular basis.

There is therefore a need for an improved product and method for maintaining and enhancing dental hygiene of a pet.

SUMMARY OF THE INVENTION

The present invention provides improved products and methods for maintaining or improving the dental hygiene of a pet. More specifically, the present invention provides improved methods and products for facilitating the removal of tartar from the teeth of a pet. To this end, in an embodiment, the present invention provides a product for facilitating the removal of tartar from the teeth of a pet. A chewable product is provided that includes a therapeutically effective amount of a tartar softening agent selected from the group consisting of mild chelating agents, proteases, dextranases and weak acids and their salts. The salts may be inorganic or organic. In an embodiment, the chewable product is designed to remove tartar, at least in part, by an abrasive action. hi an embodiment, the chewable product is in an elongate, generally rectangular shape. hi an embodiment, the chewable product is in the shape of a bone. hi an embodiment, the chewable product is in the shape of a biscuit.

In an embodiment the weak acid is selected from the group consisting of those acids that preferentially react with the anions contained in tartar, but not with the tooth structure. In a preferred embodiment, the weak acid preferentially reacts with carbonate. Examples include: carboxylic acids, polycarboxylic acids, salts of sulphates, salts of phosphates, sulphonic acids, sulfamic acids, amino acids, organic acids based on sulfur or phosphorous; organic and inorganic acids derived from phosphoric acid, organic acids derived from phosphinic acid, acidic polypeptides and proteins; organic or inorganic acids based on silicon, ammonium salts, salts of amines, amino containing compounds, salts of heterocyclic compounds containing nitrogen; inorganic substances derived form soil, clays, and other inorganic compounds that act as phosphate, carbonate or hydroxide scavengers; and salts complexes and derivatives of, and polymers containing all of these. In an embodiment, the mild chelating agent is one that preferentially binds calcium and magnesium. Examples of such agents include: carboxylates, polycarboxylates, polyamino organic compounds, amino-polysaccharides, sulphonic acids, sulfamic acids, amino acids, organic acids based on sulfur or phosphorous; organic and inorganic acids derived from phosphoric acid; organic acids derived from phosphinic acid; compounds containing quaternary ammonium or phosphonium moieties, including acidic polypeptides and proteins; organic or inorganic acids based on silicon, silicates and polysilicates; and salts, complexes and polymers containing any of the above. In a preferred embodiment, the tartar softening agent is citric acid.

In an embodiment, the tartar softening agent comprises approximately 0.2% to about 10.0 % by weight of the product.

In another embodiment of the present invention, a method of controlling tartar on the teeth of a pet is provided. The method comprises the steps of: contacting a pet's teeth with an agent that disrupts an inorganic layer of a tartar structure on the pet's teeth; and subjecting the teeth to an abrasive action.

In another embodiment of the present invention the agent that disrupts an organic layer of the tartar structure on the pet's teeth is selected from a group that includes proteases and dextranases. In an embodiment of the method, the agent is in the form of a liquid.

In an embodiment of the method, the agent is contained in a structure that provides the abrasive action. h an embodiment of the method, the abrasive action is created, at least in part, by brushing the pet's teeth. In an embodiment of the method, the agent is selected from the group consisting of: organic acids and salts; chelating agents; proteases; dextranases and inorganic salts and acids. hi an embodiment of the method, the method includes the step of causing the pet to chew a product including the agent. In an embodiment of the method, the product is a bone.

In a still further embodiment of the present invention, a method of manufacturing a product for controlling tartar on a pet's teeth is provided. The method comprises the steps of preparing a chewable structure including an agent that is designed to disrupt the layers that define a tartar material located on a pet's tooth.

In an embodiment of the method, the product is constructed so as to have a bone shape. In yet a further embodiment of the present invention, a product for controlling the tartar on a pets' tooth is provided. The product comprises a chewable product including a continuous and a discontinuous phase and a tartar softening agent.

In a further aspect, the invention provides a method of maintaining or improving the health of a pet by inhibiting the spread of pathogens, having oral origin, from the mouth of the pet to other areas of its body, the method comprising facilitating the removal of tartar from the pet's teeth. The method may include the step of administering to the pet a tartar softening agent in an amount effective to soften tartar present on its teeth. The step of administering the agent may be carried out repeatedly at intervals. In an embodiment of the method, the said agent may be administered as a component of a structure that provides an abrasive action when contacted with the pet's teeth. The method may therefore further includes the steps of providing a chewable structure wherein the agent is containable, including the agent in the chewable structure in a tartar softening effective amount when the structure is orally administered according to a predetermined regimen, and administering the structure containing the agent to a pet according to such regimen.

The invention extends also to the use of a tartar softening agent in a method of inhibiting the spread of pathogens having oral origin from the mouth of a pet animal to other areas of its body, the method comprising administering to a pet a tartar softening agent in a tartar-softening effective amount, thereby facilitating the removal of tartar from the pet's teeth.

The invention provides further for the use of a tartar softening agent in the manufacture of a product comprising a chewable structure wherein the agent is included in a tartar softening effective amount when administered to a pet according to a predetermined regimen. The regimen may include administering the product as part of a meal, or as a supplement to the pet's diet. When administered as a supplement, the product is preferably provided as a treat. The invention provides generally for a method of maintaining or improving the condition of a pet, the method including the step of improving or maintaining the oral health of the pet. The oral health of the pet may be thus maintained or improved by the step of maintaining or improving the dental health of the pet. This method may include the step of facilitating the removal of tartar from the pet's teeth. Tartar removal may be achieved by orally administering to the pet a tartar softening agent in a tartar softening effective amount.

An advantage of the present invention is to provide an improved product for providing dental hygiene to a pet. Moreover, an advantage of the present invention is to provide an improved method for providing dental hygiene to a pet.

Still further, an advantage of the present invention is to provide an improved product that facilitates the removal of tartar from the teeth of a pet.

Another advantage of the present invention is to provide an improved method for removing tartar from the teeth of a mammal.

Furthermore, an advantage of the present invention is to provide an improved method for cleaning the teeth of a pet.

Yet another advantage is to provide a method for assisting in maintaining and improving the general health and condition of a pet. Additional features and advantages of the present invention will be described in and apparent from the detailed description of the presently preferred embodiments and the figures.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 illustrates a cross-sectional view of a mouth of a pet.

Figure 2 illustrates schematically dog tartar as seen under a scanning electron microscope.

Figure 3 illustrates an embodiment of a product for enhancing the dental hygiene of a pet.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS The present invention provides improved products and methods for providing dental hygiene to a pet. More specifically, the present invention is directed to products and method for enhancing the removal of tartar from the teeth of a pet.

The invention further provides a method of maintaining or improving the health of a pet by inhibiting the spread of pathogens, having oral origin, from the mouth of the pet to other areas of its body, such as its vital organs. Through facilitating the removal of tartar from the pet's teeth, the accumulation, propagation and spread of such pathogens is inhibited. This is expected to have a beneficial effect on the general or overall health and condition of the pet. The method may include the step of administering to the pet a tartar softening agent in an amount effective to soften tartar present on its teeth. The step of administering the agent may be carried out repeatedly at intervals accordmg to a predetermined regimen. For example, the agent may be administered daily and as a component of a structure that provides an abrasive action when contacted with the pet's teeth. An embodiment of such a structure will be described in greater detail below.

The tartar softening agent of the invention may be used in the manufacture of a product having a chewable structure and where the agent is included in a tartar- softening effective amount when the product is admmistered to a pet according to a predetermined regimen. The regimen may include administering the product as part of a meal, or as a supplement to the pet's diet. When administered as a supplement, the product is preferably provided as a treat. The agent may be included by mixing it in with the remaining ingredients for producing the chewable structure. This method is appropriate where the structure is to be extruded. If the structure is of a porous nature, the tartar-softening agent may be infiltrated or impregnated into the product matrix. Alternatively, it may be sprayed, dusted or coated on, according to techniques well known in the art.

Referring to Figure 1, a cross-sectional view of the mouth 10 of a pet is illustrated. The portion of mouth 10 illustrated includes the cheek 12 and buccal cavity 14. Located within the mouth 10 are the gums 16 and teeth 18. The area between the gums and teeth is the gingival cavity 20.

It is of course known that tartar can accumulate on the surface 22 of the teeth 18 of a pet. As set forth in the background of the invention, tartar build-up in the gingival cavity 20 can be especially detrimental. Further, as set forth in the background of the invention, it is more difficult to clean the teeth 18 located in juxtaposition to the buccal cavity 14.

Referring now to Figure 2, a schematic cross-sectional view of an electron microscope view of tartar 24 is illustrated. The inventors have found, through electron microscope studies on dog tartar, that tartar 24 has an unusual structure. It comprises a number of layers. Illustrated in Figure 2 are four representative layers, 26, 28, 30, and 32. Layers 26 and 30 are layers comprised of inorganic material such as calcium salts and complexes incorporating carbonate and phosphate anions. These are typically the thickest layers of the tartar 24 and comprise primarily porous, inorganic material. This porous material includes holes typical of oral bacteria. Underneath each of the inorganic layers 26 and 30 are layers 28 and 32 composed of proteinaceous organic material.

The inventors have surprisingly found that it is possible to soften tartar 24 by disrupting either of the inorganic layers 26 and 30 and/or proteinaceous organic layers 28 and 32. Accordingly, in an embodiment pursuant to the present invention, the inorganic layers 26 and 30 are subjected to a composition that disintegrates, or at least disrupts, the inorganic layers and turns them into a soft mucus similar to the proteinaceous mass. For example, Applicants have surprisingly discovered that when placed in a 3% solution of citric acid that pet tartar disintegrates and turns into a soft mucus-like proteinaceous organic mass.

Therefore, pursuant to the present invention, in an embodiment, a product is provided that includes an agent that is designed to disintegrate, or at least soften, the inorganic layers 26 and 30 of the tartar 24. The agent can be supplied in a variety of types of products.

Referring to Figure 3, an embodiment of a product 40 that can be used to facilitate the removal of tartar is illustrated. The product 40 includes an active agent that will dissolve or soften the inorganic layers of tartar. A variety of active agents can be utilized. For example, the active agent can include an organic acid or salt, a mild chelating agent, proteases, dextranases or weak inorganic acids and salts. A preferred organic acid is citric acid. Preferred chelating agents include those that preferentially bind calcium and magnesium, e.g. EDTA, cyclodextrans, chitosan and derivatives. Other possible active agents include inorganic or organic agents that can react with or solubilise anionic components of the tartar - especially carbonates and phosphates - but not react with the tooth surface. These may include: sulphonic and sulfamic acids, organic acids based on sulfur or phosphorous, organic and inorganic acids derived from phosphoric acid, organic acids derived from phosphinic acid, compounds containing quaternary ammonium or phosphonium moieties; amino acids, including acidic polypeptides and proteins; organic or inorganic acids based on silicon, silicates and polysilicates, as well as salts and complexes of, and polymers containing the above. The active agent should be included in the product so that it comprises approximately 0.2 % to about 10 % by weight.

The body portion 42 of the product 40 can comprise a variety of different substrates. An example of a product that can be utilized is set forth in U.S. Patent Application Serial No. 60/280,064 entitled. In that application, a body 42 having a continuous and discontinuous phase is provided. As set forth in that application, the continuous and discontinuous phases provide a number of advantages in that it facilitates a cleaning action. When this cleaning action is coupled with the active agent of the present invention, Applicants believe that synergistic results are provided.

It should be noted that although Figure 3 illustrates a bone shaped embodiment of the product 40 of the present invention, a variety of products can be utilized to deliver and facilitate the removal of tartar. Such products include shaped products such as biscuits and other chew products as well as mouthwashes, drinks, toothpastes or tooth gels, toothbrushes impregnated with the agent, and the like.

By way of example and not limitation, illustrative examples of the present invention will now be given:

Example 1

An edible chew style product for dogs was made by extrusion in accordance with the following formula.

A mixture of dry ingredients was prepared by adding to a Sovemeca Mixer (Sovemeca Ltd, Vermand , France). These ingredients were mixed intimately before being fed to a long barrel twin screw Clextral extruder. Applying SME of about 320J/J, with the simultaneous addition of 1 part glycerol to 3 of the powdered ingredient mix, the total mixture was heated to a plastic state. Without raising the internal pressure above 2 atmospheres, the plastic mixture was released through a die to form a strip about 12 mm thick and transferred on a belt heated to about 50°C to a cutting station, where a rotary cutter was employed to divide the extruded stream into blocky, rectangular bodies of dimensions about 125mm x 52mm x 12mm. These were allowed to cool gradually to 18°C before being hermetically packaged for later addition to a pet meal.

Example No. 2 To demonstrate the effectiveness of the product of this invention as exemplified in example 1, 3 g of the product was thinly shaved with a razor blade and placed in ajar together with 15ml of water. It was designated "Product IT." A second jar was filled with 15ml of water and designated "Water Control." Two extracted dogs' teeth (Premolar 4) were selected for testing. Each of these teeth had an equivalent heavy coverage of tartar. One tooth was placed into each jar. The jar was then sealed and left undisturbed for 3 hours. The teeth were removed and gently washed with water and air dried.

The surface of the tartar on both teeth was gently scratched with a fine probe. It was found that the tartar on the tooth in "Product IT" was distinctly softer and easily etched by the probe, h contrast the tartar, on the tooth in the "Water control" was not easily scratched. The tartar on the tooth in "Product IT" had also significantly lightened in color. Applicants believe this indicates a change in its chemistry.

This experiment demonstrated that the components of the product of the present invention help soften tartar. This makes the tartar on teeth more susceptible to the abrasive mechanical action that occurs when a pet product is chewed.

Example No. 3

Each day, over a period of 21 days, each member of a group (designated "NewProd") of 12 beagle dogs was individually fed one of the products made pursuant to example 1 above, in addition to a diet of a canned commercial petfood. The product of example 1 constituted approximately 25% of the dog's total diet by weight.

A second group (designated "Control") of 12 beagle dogs was simultaneously fed on only the canned commercial pet food. At the end of the period, both groups were assessed for the accumulation of tartar on their teeth.

For further comparison purposes, a third group of dogs was defined and, instead of being fed the product of the present invention, this group (designated "Biscuit") were fed commercial dog biscuits in an equivalent quantity (i.e. at -25% of diet by weight). Before commencement of the test, an oral examination had been conducted on each dog prior to selecting it for the trial. Dogs with known or observed dental/oral problems (e.g. severe periodontal disease, excessive number of missing teeth etc) were not included.

Each dog was put through preliminary screening to check its feeding behaviour. Prior scoring was done to assess how each of the dogs chewed a standard treat. They were grouped into blocks depending on their observed behaviour. The behaviour groupings were very fast chewers, moderate chewers and slow chewers.

Dogs were blocked for assignment to the diets on the basis of this chew score, age and sex. Diets were assigned randomly within blocks. The dogs were confined indoors to eat. For the groups receiving the Example 1 product and the comparative commercial dog biscuit, these was given in a bowl, 4 hours after the main meal, in the morning. The bowl was removed 1 hour after and the amount of treats not eaten was scored and measured.

A complete dental assessment was performed on all dogs on the first day of the test period to determine their existing tartar scores. On day 21, the examination was repeated. On each occasion the dogs were sedated for a brief period of time (several minutes) to enable their tartar scores to be determined. The teeth were first gently brushed with a toothbrush, rinsed with a forced stream of water, then air-dried. The tartar was then visually recorded for the proximal, distal and mesial thirds of the buccal surfaces of the teeth. The amount of the surface covered with tartar in a particular 1/3 segment was scored as 0 = no plaque; 1 = < 25 %; 2 = 25 - 49 %; 3 = 50 - 74 %; 4 = 75 - 100 %. The thickness of the tartar was scored as 1 = Light; 2 = Moderate; 3 = Heavy. Total score for one tooth was achieved by multiplying the thickness and coverage scores for each segment and summating the resultant values of the 3 segments. The scores for all surfaces for each animal were added and divided by the number of teeth to provide each animal's individual score. A mean group score was obtained by averaging the scores of all the members of the group. A note was also made of the incidence of gingivitis on the adjacent gum line.

The results in table 1 show that the product of the present invention is significantly more effective in actually reducing existing tartar on dogs' teeth when compared to the control and even to competing biscuits.

Table 1: Mean Group Tartar Scores

It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.

Claims

CLAIMS:

1. A product for facilitating the removal of tartar from the teeth of a pet comprising: a chewable product including a therapeutically effective amount of a tartar softening agent selected from the group consisting of organic acids and salts, mild chelating agents, proteases, dextranases and weak inorganic salts and acids.

2. The product of Claim 1 wherein the mild chelating agent preferentially binds calcium and magnesium.

3. The product of Claim 2 wherein the mild chelating agent is selected from the group consisting of: carboxylates, polycarboxylates, polyamino organic compounds, amino-polysaccharides, sulphonic acids and salts and complexes or polymers containing these ; sulfamic acids and salts complexes or polymers containing these; organic acids based on sulfur and salts, complexes or polymers containing these; organic and morganic acids derived from phosphoric acid and salts complexes or polymers containing these; organic acids derived from phosphinic acid and salts, complexes or polymers containing these; organic acids based on phosphorous and salts, complexes or polymers containing these; chemicals containing quaternary ammonium or phosphonium moieties; amino acids and salts, complexes or polymers containing these including acidic polypeptides and proteins; organic or inorganic acids based on silicon and salts, complexes or polymers containing these including those based on the silicates and polysilicates. Also possible are microbial fermentates containing carboxylic acids and salts, complexes or polymers containing these and polysaccharide or sacchride based chelating agents.

4. The product of claim 1 wherein the tartar softening agent is selected to react with/ solublise the anionic components of the tartar but not the tooth surface. The product of Claim 4 wherein the tartar softening agent is selected from the group consisting of: sulphonic and sulfamic acids, organic acids based on sulfur or phosphorous, organic and inorganic acids derived from phosphoric acid; organic acids derived from phosphinic acid, compounds containing quaternary ammonium or phosphonium moieties; amino acids, including acidic polypeptides and proteins; organic or inorganic acids based on silicon, silicates and polysilicates, and salts, complexes and polymers being of or containing any of these.

The product of claim 5 wherein the tartar softening agent is selected from the group consisting of microbial fermentates containing carboxylic acids, polysaccharide or sacchride based chelating agents, and salts, complexes and polymers being of or containing any of these.

The product of Claim 1 wherein the tartar softening agent is citric acid.

8. The product of any one of the preceding claims wherein the tartar softening agent comprises approximately 0.2 % to about 10 % by weight of the product.

9. The product of any one of the preceding claims wherein the chewable product is designed, in part, to remove tartar by an abrasive action.

10. The product of any one of the preceding claims wherein the chewable product is in the shape of a bone.

11. The product of any one of the preceding claims wherein the chewable product is in the shape of a biscuit.

12. The product of any one of the preceding claims having a continuous phase and a discontinuous phase.

13. A method of controlling tartar on the teeth of a pet comprising the steps of contacting a pet's teeth with an agent that disrupts an inorganic layer of a tartar structure on the pet's teeth and subjecting the teeth to an abrasive action.

14. The method of Claim 13 wherein the agent is in the form of a liquid.

15. The method of Claim 13 or Claim 14 wherein the agent is contained in a structure that provides the abrasive action.

16. The method of any one of claims 13 to 15 wherein the abrasive action is created, at least in part, by brushing the pet's teeth.

17. The method of any one of claims 13 to 15 including the step of causing the pet to chew a product including the agent.

18. The method of Claim 17 wherein the product is bone shaped.

19. The method of any one of claims 13 to 18 wherein the agent is selected from the group consisting of: organic acids and salts, chelating agents, proteases, dextranases and inorganic salts and acids.

20. A method of manufacturing a product for controUmg tartar on a pet's teeth comprising the steps of preparing a chewable structure and including in it an agent that is designed to disrupt at least one layer of a tartar material located on a pet's tooth.

21. The method of Claim 20 including the step of forming the chewable structure in a shape to resemble a bone.

22. The method of Claim 20 including the step of forming the chewable structure as a biscuit.

23. Use of a tartar softening agent in a method of inhibiting the spread of pathogens having oral origin from the mouth of a pet animal to other areas of its body, the method comprising administering to a pet a tartar softening agent in a tartar-softening effective amount, thereby facilitating the removal of tartar from the pet's teeth.

24. Use as in claim 23 including administering the agent repeatedly at intervals.

25. A method of maintaining or improving the overall condition of a pet, the method including the step of administering to the pet an agent that is effective to maintain or improve its oral health.

26. The method of claim 25 wherein the agent is effective in maintaining or improving the dental health of the pet.

27. The method of claim 26 wherein the agent is effective in facilitating the removal of tartar from the pet's teeth.

28. The method of claim 26 or claim 27 wherein the agent is a tartar softening agent.

29. The method of any one of claims 25 to 28 including the step of providing a chewable structure wherein the agent is containable, including the agent in the chewable structure in a tartar softening effective amount when the structure is orally administered according to a predetermined regimen and administering the structure containing the agent to a pet according to such regimen.

30. The method of claim 29 wherein the structure is capable of abrading tartar on the pet's teeth when chewed.

31. The method of claim 29 or claim 30 wherein the structure is edible

2. The method of any one of claims 29 to 31 wherein the structure has a continuous phase and a discontinuous phase.