Dental Archives - Birnam Veterinary Clinic

What is the brownish yellow discolouration on my pet’s teeth?

Just like humans, dogs and cats have two different sets of teeth. The first set, known as the deciduous teeth or “baby teeth", erupt between three to six weeks of age. The permanent or “adult” teeth start erupting around three months of age and are all present around six months of age.

The teeth are also very similar in structure to human teeth, with the crown that sits above the gum line and the root which is located below the gum line. All teeth are made up of an outer protective coating of enamel. Enamel is a very hard structure that protects the more sensitive dentin. The dentin sits over the even more sensitive pulp cavity which contains nerves and bloods vessels, which nourish the tooth.

A discoloured tooth is any variation from the normal colour. A normal and healthy tooth can be various different shades of white or cream and the gum should sit tightly around it. The normal colour can vary depending on the shade, thickness and translucency of the enamel. There are several different reasons for teeth to discolour and these reasons may be due to factors affecting the tooth from the outside or inside. Outside factors are referred to as extrinsic and mainly affecting the enamel. Inside or instrinsic factors affect the sensitive dental pulp or can affect the development of the tooth in general. Trauma or chronic wear, infection or inflammation, metabolic disease, some developmental conditions and certain drugs can all causes changes to the teeth.

If a tooth does not appear normal or changes in colour, it is important to have your pet’s mouth examined by the veterinarian to determine whether one or multiple teeth are affected. It is important to consider the pet’s age and stage of dental development and whether the dentition is deciduous, mixed or permanent. It is also important to note how long the tooth has been discoloured for. All these factors will help determine potential causes as well as treatment. Some conditions may need further testing, such as X-rays to help with the diagnosis.

What are the different causes of tooth discolouration?

Trauma – dogs can be quite persistent when chewing objects such as toys or bones. Some dogs get into a bad habit of chewing rocks or other very hard things. These can cause chips and fractures but can damage the tooth without breaking it. Accidents such as being hit by a car, or cats falling from a height, can also cause tooth trauma.

Initially the pulp becomes inflamed and bleeds. This results in a pink colour to the tooth and is referred to as pulpitis. The pulpitis may resolve and the tooth can return to normal but more commonly the tooth changes to purple, tan, brown, black or any intermediate colour. It can be painful initially but the pain usually resolves with time. The tooth often can become infected with bacteria and this infection can spread throughout the body.

Plaque – Just as with humans, animals can also suffer from plaque and calculi build up on teeth. Plaque formation is due to bacteria that naturally occur in the mouth that, together with the cells on the inside of the surface of the mouth which are replaced with new cells, create a film over the surface of the teeth. This film thickens and hardens with time. In very severe cases, it can cover the whole tooth. The bacteria present in plaque can penetrate below the gum line and start to affect the tooth root too.

Calculi – Calculi is the hard yellowish brown substance that “grows” on teeth when the plaque is not properly removed from the teeth and starts calcifying and hardening over a period of time. Imagine the results of not brushing your own teeth for months on end. The harder and more irregular the surface becomes, the more plaque tends to build up leading to a vicious cycle of the dental health deteriorating.

Foods and medications – some pigmented foods and certain medications can cause discolouration to teeth. Tetracyclines which is an antibiotic (which by the way is very rarely used these day any more) used in young dogs while the teeth are erupting cause a distinct yellow discolouration as they affect the formation of the enamel.

Systemic infection and fever – In young dogs and cats, illness while teeth are erupting can cause defects in the enamel. As the enamel is the protective layer of the tooth, any defect makes the rest of the tooth more susceptible to infection and damage. In some dogs, a distinct line in the enamel may be noted and this usually correlates to the time of infection.

Developmental conditions – amelogenesis imperfecta is a condition in which the enamel does not calcify enough and so is softer than it should be which may cause discolouration. Dentinogenesis imperfecta is a condition where the dentin does not develop properly and the structure and integrity of the tooth is compromised and once again may cause a change in colour of the affected teeth.

What can be done?

The treatment for discoloured teeth will depend on the cause. Sometimes all that needs to be done is a “dental” by the vet which entails an ultrsasonic scaling and polishing of the teeth to remove the plaque and calculi build up. Unfortunately with dogs and cats, this needs to be done under general anaesthetic as we cannot ask them to sit still and keep their mouths open. Brushing teeth with special pet tooth paste and giving dental treats and chews can delay the buildup of calculi but unfortunately some pets are more prone to developing dental calculi and plaque than others. In some cases, if the root is exposed or infected it will need to be extracted.

It is very important that if you do brush your pets’ teeth that you do not use human toothpaste but instead get a special veterinary toothpaste from your vet.

If the tooth is traumatised, some cases may require root canal treatment. This is where the pulp is cleaned out, disinfected and then filled with a hard substance that sets. This is not suitable in all cases and is considered a specialist dental procedure. In most cases the veterinarian will advise extraction of the affected tooth or teeth.

Defects in the enamel can be difficult to correct and manage. The vet should be equipped to deal with most of these conditions but may recommend that you seek a veterinary dental specialist’s advice for complicated cases. The veterinary dentist specialist may attempt to remove the affected enamel and apply a bonding agent but the success of this will depend on the extent of the lesions.

Discoloured teeth in animals instead of a “bright and healthy set of pearlies” in most instances indicate that something is wrong with the animal’s teeth. Always ask the vet for advice and rather be pro-active and have it addressed properly than wait and in the end let the animal lose their teeth.

Periodontal disease in dogs and cats

“My dog/cat has bad breath!” This is probably one of the most common complaints vets hear from pet owners. Halitosis (bad breath) can be caused by many things, but is most often related to dental disease.

Nowadays pets are part of the family. They sit next to us on the couch when we watch television, they sleep with us in our beds and we even take them on holiday – they are practically human! This means we take better care of them and they therefore live much longer. Fortunately, as a result of this close relationship, we notice problems like bad breath much earlier (one cannot help but smell something if you share your pillow with a furry friend) and we can do something about it so much sooner.

Periodontal disease in a nutshell:

“Peri” is the Greek word for “around” and “don't" is related to dental or teeth. So, periodontal disease refers to disease of the area around a tooth.

This comes about by food and bacteria collecting along the gum line to form plaque. If this plaque is not removed it can lead to a hardened form of plaque called tartar or calculus which sticks strongly to the teeth. It is caused by the continual accumulation of minerals from saliva on plaque on the teeth.

Plaque can be removed by brushing but calculus or tartar is too hard and attached too firmly to the teeth to be removed with a toothbrush or by eating pet food, even if it is in a dry pellet format (kibbles).

The tartar is irritating to the gums and causes inflammation; this is referred to as gingivitis and can be recognised by bad breath and reddening of your pet's gums. When the gingiva or gums become so irritated that there is a loss of the connective tissue fibres that attach the gums to the teeth and the bone that surrounds the tooth, this is known as periodontitis.

If the calculus is not removed, it builds up under the gums. It separates the gums from the teeth to form “pockets” and encourages even more bacterial growth. At this point, the damage is irreversible and called periodontal disease. It can be very painful and can lead to loose teeth, infection, abscesses and even bone loss of the jaw.

What signs would you see in your pet?

In cases where the condition has not deteriorated significantly you may not notice any signs and therefore it is important to lift up your pet's lips and look into their mouths to see if any calculus (tartar) has started building up. The sooner one addresses the onset of periodontal disease, the less likely your pet is to lose any teeth and the better the chance of preventing further complications like heart or kidney disease.

Once the disease has progressed further varying degrees of the following symptoms may be noticed:

Bad breath (Halitosis)
Drooling
Mouth pawing/rubbing
Not eating or eating less
Difficulty chewing
Red and inflamed gums (Gingivitis)
Gums that bleed easily
Loose teeth, missing teeth
Pus around a tooth
Irritability or depression

Many things can play a role in the development of dental disease:

Some breeds are more prone than others.

In dogs we see it more commonly in smaller breeds (yorkies, poodles etc). Their teeth are often crowded together or they may have extra teeth because of retaining some of their baby teeth. Breeds with flat faces like pugs, bulldogs and boxers are also prone to dental disease because their teeth are not always well aligned.
In cats it is more common in Oriental short-hairs and Siamese cats.

The age of your pet.

Dental disease more often affects our older pets and research has shown that more than 65 % of pets older than 7 years of age have some form of dental disease.

The food we feed our pets can play a role as well.

Studies have shown that hard kibbles are slightly better than soft food in reducing plaque. The grinding action required by chewing this food tends to clean teeth better.

Chew toys

Dogs that chew on various toys or special dental chews have less plaque than those who do not.
The wrong chew toys can also have an effect. Very hard chews (dried cow hooves) or bones can cause the teeth to break or wear down faster. Many people will then wonder why wild carnivores can eat bones and not have problems. Unfortunately they do! Up to 50% of them have broken teeth as a result of this. We should also remember that they do not live as long as our pets (maximum of up to 4-5 years) and therefore do not often show symptoms, where many of our little ones have a lifespan of nearly 15 years. Can you imagine living with toothache for that long!

Inappropriate chewing

Some dogs chew inappropriate things such as sticks and stones. This will have the same effect as having the wrong chew toys. Unfortunately, this is a behaviour problem in many dogs and can be very difficult to unlearn. They also often swallow these things, which in turn lead to other major problems. Correct training at a young age is therefore very important.

Why do vets make such a fuss about dental health?

You might think that bad breath is normal for a dog or cat and that worrying about it is a waste of time. Well, it is not! Bad breath can be just the tip of the iceberg. The sooner we treat dental disease the better. The horrifying thing is that periodontal disease is irreversible and it can also cause major organ disease. Most people do not know that bad teeth can cause heart disease and kidney and liver failure. These are deadly!

What can you as a pet owner do about it?

The best thing for your pet is to go to his/her veterinarian on at least an annual basis! In human terms this would translate to visiting the doctor roughly every seven years. Your vet will not only check their teeth, but will also quiz you on their general well-being and behaviour. With this information the vet can make an informed decision on how to proceed. Most commonly the vet will suggest a dental scale and polish. This is the same procedure we go for to clean our teeth at a human dentist but with one BIG difference – our pets need a general anaesthetic as they do not respond well to „sit still? and „open wide?. This obviously carries risks, making the general check-up extremely important. Conditions such as heart and kidney disease may affect your pet during anaesthetic.

To most of us our pets are very special and much loved. It is our duty to keep them healthy and fit – just as we do ourselves. The small things we do can make such a big difference in their lives, even smelling their breath every now and then!