Feline dentistry - how homecare can help

Dental disease is a very common problem in both young and old cats. It is thought that as many as 85% of cats aged three years and older have some sort of dental disease. This lecture aims to give you information about some of the most common types of dental disease, what signs your cat will show, how this is diagnosed, what this means for your cat and how you may be able to prevent some of these diseases.

Although domestic cats can live without teeth, teeth are important, especially for wild cats, for a number of reasons. These include: -

Each tooth sits in a socket held firmly in place by ligaments, cementum (bony like substance) soft tissue and bone. The tooth is divided into the crown and the root. The crown of the tooth is the visible part of the tooth above the gingiva. Below the gingiva is the tooth root. The point at which the crown and the root meet is termed the neck of the tooth.

Pulp – Pulp lies within the centre of the tooth called the pulp cavity. Pulp enters the cavity at the tip of the root and contains cells nerves and blood vessels. Because of this, damage or inflammation of the pulp is extremely painful.

Dentine – Dentine covers the pulp and is the main bulk of the root as well as providing a middle layer between the pulp and the enamel on the crown of the tooth. Dentine is hard and mineralised but is very sensitive making root exposure or enamel damage very painful.

Enamel - Enamel is a hard, mineralised substance, which is insensitive. Enamel covers the crown of the tooth protecting the dentine and therefore preventing sensitivity when the animal is eating. However, feline dental enamel is thin, measuring only 0.2mm thick compared to canine dental enamel, which is 0.5mm thick. Damage to the enamel exposing the dentine will result in a very sensitive tooth, which is susceptible to infection.

During evolution, the feline dental arcade has precisely developed so that each tooth plays an important role in the ability for a wild cat to survive. A cat has thirty teeth in total. The different types of teeth are: -

Incisors (I) – These are the very small teeth at the front of the mouth (see diagram). Incisors have minimal use but are used to help hold prey in the mouth. They only have one root and are quite often unstable making extraction easy. A cat should have twelve incisor teeth in total (six at the top and six at the bottom) but quite often some of these teeth will fall out or not even develop.

Canines (C) – The cat is a true carnivore, and these are the teeth responsible for killing and shredding prey. They only have one root but this root is very long and is supported by strong ligaments and bone making removal difficult. Cats should have four canines.

Pre-molars (PM) – Cats should have six upper pre-molars (UPM)(three each side) and four lower pre-molars (LPM)(two each side). The two lower pre-molars are labelled as PM2 and PM3 (see diagram below). They are used for chewing prey and have various roots: -

When removing these teeth it is essential to know how the tooth roots are divided to ensure the tooth is split in the correct place allowing easier extraction.

Molars (M) – Cats should have two upper molars (UM) (one each side) and two lower molars (LM)(one each side). Molars are also used for chewing but upper and lower molars have different roots. These are: -

Upper molars are usually easy to remove as they have short roots with no bone attachment. Lower molars are more difficult to remove as these have one thick root and one small root with bone and ligament attachment.

Plaque is a complex film of bacteria that develops on the surface of teeth. Initially the layer of plaque is not readily visible, but it can be demonstrated by using a disclosing solution that stains the plaque film. As the plaque layer grows and becomes thicker, it can often be seen as a soft, grey or white film on the tooth surface. Plaque is important because it is the most common cause of dental disease. Taking measures to help reduce dental plaque development is therefore an important step in trying to prevent dental disease in cats. Plaque can be removed with brushing helping to keep the gums healthy.

If plaque is left undisturbed it can become hardened due to deposition of substances such as calcium in the plaque layer. Hard, calcified plaque is known as tartar or calculus. Tartar is clearly visible and looks like a cream/yellow or brown hard deposit on the tooth surface. Tartar cannot usually be removed by simple measures such as brushing, consequently professional scaling is required to remove it.

Dental disease can affect cats of any age and varies in severity - disease is not necessarily worse in older cats. Several factors affect the likelihood of disease occurring, including the following: -

Teeth that are positioned abnormally in the mouth are more likely to accumulate plaque and tartar than those which are correctly positioned. Reasons for misalignment include: -

Short nosed breeds e.g. Persians, Chinchillas, British and Exotic Shorthairs often have abnormally positioned teeth. Their jawbones are often too small to accommodate the dentition, resulting in overcrowding and misalignment of teeth.

In some circumstances, deciduous teeth (baby/milk teeth) are retained after the permanent teeth have grown through (erupted). If the adult tooth does not push out the deciduous tooth when it erupts the adult tooth may be forced to grow in an abnormally resulting in permanent misalignment.

Sometimes the jaw of a cat may be of an abnormal shape. If a cat is born with a jaw defect then this can be associated with tooth misalignment and developmental abnormalities e.g. undershot/overshot jaws. Another cause would be trauma resulting from a road traffic accident.

Diet is thought to play a role in the progression of dental disease. It is arguable that soft, wet foods provide no abrasive action against the teeth when chewing and so offer no prevention of plaque formation. These foods collect and attach to teeth encouraging bacteria and plaque formation. Dry foods are more abrasive and encourage chewing. They are less likely to attach to the teeth and so plaque formation is slower. Diets specifically aimed to help prevent tartar formation are now readily available. These diets are designed to increase tooth penetration of the kibble/ biscuit and so provide a more abrasive action against the tooth to reduce tartar accumulation. However, at present, their long-term efficiency in reducing gum disease is unproven.

Brushing a cat's teeth is likely to be the single most effective way to reduce plaque. Like humans, brushing will not only prevent plaque and tartar formation; it will also promote healthy gums and reduce halitosis (bad breath). Daily or even twice daily brushing is recommended and can be introduced to a cat at any age. However this must be done gradually and guidance will be discussed later.

Some cats will always seem to be prone to dental disease in spite of every effort made to prevent this. It is thought that the chemical make up of the saliva is one factor affecting dental and gum disease in these cats as well as host factors including immune response. Rigorous home care or in severe cases multiple teeth extractions, may be needed to help them.

Some infectious diseases are associated with gingivitis and the vet may advise screening for Feline Immunodeficiency Virus (FIV), Feline Leukaemia Virus (FeLV) and Feline Calicivirus.

Cats should ideally have their teeth professionally examined at least once every 12 months and cats that have had dental problems once every 3-6 months depending on their condition. Generally, the sooner the problem is identified, the easier and quicker it is to treat. Even if the cat's mouth is being examined every day, dental disease will develop and gradually progress. Cats will quite often not show clinical signs until the disease is advanced by which time many teeth may need to be extracted.

Periodontal disease means any disease around the outside of the tooth. The most common types of dental disease are as follows: -

Gingivitis means inflammation of the gingiva (gum surrounding the tooth). Gingivitis is extremely common, found in cats of all ages and varies widely in severity.

Mild gingivitis is very common in cats of all ages. It can occur as quickly as 48 hours after cleaning when plaque formation will have begun. Mild gingivitis does not effect the tooth root and brushing the teeth on a daily basis easily reverses most cases.

Moderate gingivitis is also very common. If plaque is allowed to form on the teeth then the gingiva will become more inflamed as time progresses. Sometimes gum recession can be seen at this stage. Gingival "pockets" may also be evident. A gingival pocket is where the gum has started to separate from the tooth, providing a perfect site for food, bacteria, plaque and tartar to form. If calculus hasn't already formed, most cases of moderate gingivitis can also be reversed with regular daily or twice daily brushing. However pocket formation is difficult to reverse.

Severe gingivitis can be very painful for a cat. The cat may show signs of hypersalivation (drooling), halitosis, pawing at the mouth and difficulty eating. Severe gingivitis is common in cats that have a lot of plaque and calculus on their teeth. Gum recession is also common, but may not always be obvious since the gums are so inflamed. Gingival pockets can sometimes be seen and are usually deeper than those found with moderate gingivitis. Severe gingivitis cannot usually be reversed with brushing, and often the mouths are too sore to brush. The cat will usually require a general anaesthetic to carry out a scale and polish of the teeth. If there is a severe degree of gum recession exposing the tooth root then the tooth may need to be extracted. Brushing is strongly advised post operatively to prevent the disease from recurring.

Cats of around five months of age quite commonly develop gingivitis and sometimes owners will notice a more obvious smell to their cats breath. This is usually due to permanent teeth erupting through the gums and loss of deciduous teeth causing gum disturbance and inflammation. Sometimes owners will report that they have found a tooth lying on the carpet at home! This is completely normal and will normally take 4-6 weeks to settle down. However if the cat is showing any signs of discomfort then the cat should be examined by a vet.

Periodontitis is gum disease that is very advanced and more commonly found in older cats. The gums are usually very inflamed and often recessed. Large amounts of calculus are usually present on the teeth. The ligaments surrounding and supporting the tooth are also diseased and have begun to break down exposing the tooth root and causing the tooth to be very unstable. Infection is common and often pus can be seen surrounding the tooth. Clinical signs can be seen to those of severe gingivitis. At this stage the tooth is so diseased that extraction is the only treatment option.

Stomatitis means inflammation of the oral cavity. Cats can suffer from a condition known as Lymphocytic Plasmacytic Gingivitis Stomatitis Complex (LPGC) where the entire oral cavity becomes severely inflamed. The exact cause is still unknown. This is an extremely painful disease and cats will commonly stop eating, hypersalivate (drool), paw at the mouth and show other signs of mouth pain. They will quite often lose weight as of consequence of their reduced appetite. Various treatments including antibiotics and anti-inflammatories have been used with mixed results. Treatment often includes an initial anaesthetic to clean and remove any diseased teeth followed by daily mouth washes with a chlorhexidine solution to reduce bacteria in the mouth and brushing if the cat will tolerate this. Very often cats will need to be managed on antibiotic and corticosteroid therapy. In some very severely affected cats, extraction of all of the cheek teeth is required.

Feline odontoclastic resorptive lesions (FORL) are very common in both young and old cats. It has been estimated that 72% of cats over five years have at least one FORL. A FORL is a cavity in the tooth, commonly formed around the gum line but can also be found below the gum line. The cause of them is unknown but cells called odontoclasts are found in the cavities. Odontoclasts are cells that breakdown the substance of the tooth. When examining a cat's mouth a FORL can look like there is a small amount of gum growing up the tooth. In fact the gum is inflamed due to the cavity and reacts by "filling in" the hole in the tooth. FORLs can be diagnosed by radiography and also by probing the tooth to check for a cavity. Probing should only be performed when under the cat is under general anaesthesia as FORLs are extremely sensitive and cats will classically chatter their jaw in pain if the area is touched. If FORLs are left to develop then gradual erosion of the tooth resulting in root retention will occur. Cats can show signs similar to those with periodontitis, and jaw chattering when eating is also common. The cavities produced by FORLs are not due to decay like human and canine dental cavities. Therefore filling is unsuccessful as the tooth will continue to erode. Unfortunately teeth with FORLs need to be removed.

Fractured teeth need to be assessed individually before deciding if extraction is necessary. As a general rule, teeth that have fractured through to the dentine or pulp cavity (affecting the nerve and blood supply) are likely to need extraction as the tooth will be painful and it will be at great risk of developing an infection and tooth root abscess. If only the tip of a crown is fractured, and the dentine or pulp cavity are not exposed then the tooth may not need to be extracted. However, the enamel covering a cats tooth is so thin that the majority of fractured teeth will almost certainly have to be removed. A probe can be used to assess if the tooth needs extracting. Signs such as pawing at the mouth, hypersalivation and favouring one side of the mouth when eating may be seen in cats with a fractured tooth.

Understandably animals will not sit still and “open wide” for dental work to be done therefore dental work should always be carried out under a general anaesthetic. Conscious hand scaling of the teeth is not advisable as this may expose a cavity hidden by the tartar, which will cause intense pain to your cat, therefore making your cats mouth worse.

Dental disease can quite often be overlooked and there can be a tendency to “put dental work off” as the cat may not be showing clinical signs, and anaesthetising an older cat can be very worrying for owners. However the longer the teeth are left, the longer the anaesthetic and procedure will take if done at a later date when dental disease has progressed. Measures can be taken to reduce the risk of an anaesthetic. Blood tests can be taken preoperatively to check various parameters including liver and kidney function. Because anaesthetics can lower your cats blood pressure, intravenous fluid therapy can also be given to help support the circulation throughout the anaesthetic. If you are worried about your cat undergoing an anaesthetic then you should discuss your concerns with your vet.

Homecare

Once a cat has had dental work, it is usually advisable to give the cat a few days to allow its mouth to heal before starting homecare, particularly if your cat has had any teeth removed. After this time, homecare should be started as soon as possible.

Homecare can be started at any age, but as a general rule the earlier the cat is introduced to it the easier it is for the cat to adapt to the routine and procedure. Kittens usually do not take long to become accustomed to brushing, whilst older cats may need a slow and gradual approach. Whether it is a kitten or an elderly cat, homecare should be performed in the same way.

It is useful for both the owner and cat to establish a routine, so it is advised to choose a time that is convenient to make sure brushing is done everyday. Homecare is ideally done after the cat has eaten but this is not essential as you may wish to give the cat its meal as a reward after brushing.

When planning to brush a cat's teeth it is important to use the correct equipment. Never use human dental products on a cat. Specific animal dental products are readily available.

• One cat toothbrush per cat. Never share a toothbrush between two cats, as saliva is a major route for cross infection.

• One tube of animal toothpaste - Animal toothpaste doesn't foam in the mouth as with human toothpaste. Not only is this better tolerated by cats but also it is suggested that the foaming agents can cause gastritis. Also the toothpaste contains no fluoride. Fluoride can cause possible toxicity if swallowed. The toothpaste usually comes in multiple flavours such as chicken, beef, fish or mint so ask the owner which one the cat may like best.

Cat starter kits are available and sometimes contain a finger brush but these should be used with extreme caution.

• For the first couple of days, build up your cat's trust by placing a small amount of toothpaste onto your finger and offering it to him/her. Some cats will instantly love the taste while others may be a bit reluctant. If this is the case, place a tiny amount onto your cat's nose. He/she will hopefully lick it off and usually once they have had a taste of it they will take it from your hand. It is useful to use the first couple of days to familiarise yourself with how you are going to hold your cat's head when brushing. To avoid startling your cat, try this when your cat is sleepy and at a different time to when you will brush. If possible try this several times a day, as you will be more confident when it comes to brushing the teeth.

It is usually better to have your cat with its back towards you rather than approaching him/her from the front. Not only is this less confrontational but if your cat wriggles then they will usually wriggle backwards. This way they will move towards you and you'll have better control over your cat rather than him/her running away!

Spread your hand wide, as a good firm but gentle grip is needed, and place the palm of your hand on top but towards the back of your cat's head and use your thumb and second finger to grip around the cheek bone under the eyes. Your index finger should be lifted so not to cover your cat's eyes.

Gently tilt your cat's head slightly upwards and then use your thumb to gently lift your cat's upper lip

Use the thumb on your other hand to gently pull down your cat's lower lip. This should give you a good view of all of one side of your cat's teeth.

• For the next 2-3 days take your cats head in the same way but instead of using your second hand to hold the lower lip down, apply some toothpaste to a cotton bud and gently rub the toothpaste onto the teeth in a circular motion. Start at the back teeth as these are usually the ones that are the most difficult to reach but are the most important teeth to brush. They are also usually less sensitive than the front teeth. Gradually work your way forwards until reaching the canine (fang) teeth.

If your cat tries to obstruct you with its feet, it is better to have an assistant to hold your cat's front legs to prevent this. If you are by yourself it may be necessary to wrap your cat in a towel if necessary. However this should be avoided if your cat gets stressed. It is far better to try to get your cat used to having its mouth touched by repeating this step little and often until you feel ready to progress to the next stage.

• It is at this stage that you may find using a finger brush useful. It can sometimes be useful as an intermediate stage before moving onto the toothbrush as you are still following the same procedure but adding the feeling of the texture of the bristles against the teeth. However you may wish to skip this stage as sometimes a finger brush can be too cumbersome to reach the back teeth and cats sometimes resent this more than a real toothbrush. If you do wish to incorporate finger brushing into your regime, extreme care must be taken to avoid being bitten.

• Finally you can start using the toothbrush. The procedure is the same; moving in small circular motions and starting from the back. Start by brushing for approximately ten seconds each side but gradually increase the time to 30-45 seconds each side.

When you first start to brush the teeth there may be a small amount of gum bleeding. This is common and you will find that as you brush more regularly the bleeding will stop as the gums become healthier.

If you find that a couple of days at each stage is too quick for your cat then take as many days as you need for your cat to adapt and feel comfortable with the procedure. The main thing is to see homecare as something pleasant and not to battle between you and your cat. Sometimes it is easier to see somebody demonstrate homecare on your cat. Most veterinary surgeries offer appointments with the nurse for this to be done so if you're having problems then contact your veterinary surgery.

Some cats will not tolerate brushing no matter how much you persevere. In these cases, there are still ways in which you can help prevent plaque and tartar formation.

• If your cat is on soft food then changing to or adding dry food to your cats diet may help to reduce plaque and tartar accumulation. However veterinary advice should be sort to ensure a change of diet is suitable for your cat.

• Cat dental chews are available and can usually be purchased from your vet. They come in fish and chicken flavours so are well accepted by cats. These may help to reduce but not prevent plaque and tartar formation.

• If your cat likes the toothpaste you can try applying some toothpaste to dry food or dental chews to allow the toothpaste to rub against the teeth

• Chlorhexidine mouthwashes/gels are available. This mild antibacterial gel which helps to reduce bacterial growth in the mouth, however prolonged use can discolour the tooth enamel.

While it is likely that your cat will need dental treatment at some stage of their life, regular homecare can dramatically improve oral health and reduce the necessity for dental procedures, which can only be of benefit to you and your cat.