Friday, March 7, 2014

Why do pets need dentals? Interview with dental veterinarian Christine Hawke

Dr Christine Hawke with a patient.
Dr Christine Hawke, founder of Sydney Pet Dentistry, and dental veterinarian at the Animal Referral Hospital, is a wonderful human being. She taught immunology and dentistry when I studied veterinary school, and she's made a huge dent (no pun intended) in companion animal welfare by promoting awareness of their dental health. I've consulted her over some tricky cases including Phil's extraordinary dental disease

SAT had a chat with her about her career, and why dental treatment important to animal welfare. (Readers who missed it might also like to read my summary of Dr Hawke's awesome feline dental extraction lecture last week).

Tell us a bit about yourself. Who are you and what do you do?

I am a dental veterinarian, meaning I only do mouths (dentistry and oral surgery). I also do a lot of teaching in vet dentistry.

Was there a lightbulb moment in your life when you decided you wanted to be a vet?

I have wanted to be a vet since I was five. My whole life plan was based on the whim of a five year old!! Luckily, I was obviously very in touch with myself at that age, as it was definitely the right decision (thankfully!). I did consider other options briefly (novelist, photographer, paediatrician) but really, it was always going to be vet science. Funnily enough, dentistry itself never crossed my radar!

Were any non-human companions influential in this decision. Who were they?

Not really. I have always loved animals, I grew up with cats (my brother was allergic to dogs), and went to an agricultural high school so there was a lot of exposure to farm animals there, but the decision was made very early on. The animals in my life just confirmed it along the way.

What moved you to focus solely on dentistry?

It’s funny, I actually hated dentistry when I was working in general practice for my first few years after graduating. We were not taught dentistry at university, so I did not understand it, and I don’t enjoy doing things I don’t understand! My plan in my early career was to travel a lot (which was made easy being a vet), then to settle down and specialise in internal medicine.

I completed a PhD in immunogenetics before my career went on hold when I fell pregnant with my first child. I then started working at the University of Sydney in the veterinary teaching hospital. As part of that job, I had to either teach desexing or dentistry – and I chose dentistry (anything to avoid doing big dog speys!). The rest is history!

Dentistry is an area that has only recently received attention in the last decade or so. Why has companion animal dentistry been neglected for so long and do we still have a way to go?

Dental disease is THE most common health problem in dogs and cats – far more common than heart disease, cancer, diabetes, and even obesity! An estimated 80% (yes that is not a misprint) of pets over the age of three have dental or oral disease.

Severe gingivitis in a cat.
I think the main reason dentistry has been relatively neglected is that people (many vets included) have simply not realised how important it is. Dental disease is insidious, silent and hidden in the dark. Unlike the obvious signs we see with other painful issues (like limping with a sore leg, weeping red skin or head-shaking with an ear infection), dental issues cause few signs. Bad breath, often the only sign in animals with infected mouths, is widely believed to be ‘normal’ for dogs and cats (there is nothing normal about bacteria, pus and rotten egg gas, which is what you are really smelling!). Signs that we’d associate with dental disease, such as dropping food or not being able to eat, only develop very late in the process, after months or years of infection and pain.

The improvement in dental health for animals has been fantastic over the past few years, thanks largely to the work of groups such as the AustralianVeterinary Dental Society. But, with many animals still affected, we still have a big job ahead to increase awareness.

As part of your role you teach veterinarians how to expand their dentistry skill set. What are common weaknesses people ask you to help them address?

Most vets really don’t like dentistry, mainly because they don’t get great dental training in university (I can totally identify with this). I help them become confident in recognising disease and competent in treating it, so they can learn to love it as much as I do! A really big part of it is helping vets and nurses communicate with pet owners so they really understand the need for dental care – if the animals won’t tell us they are struggling, then it is up to us to speak up on their behalf. Often pets don’t get dental treatment because people think they are fine because they are eating – nothing could be further from the truth.

The other main skill I love to teach is extraction technique – dental extractions can be difficult (the roots of carnivore teeth are massive!), and so it is a real thrill to help others learn better surgical skills to make this less stressful, both for the vets and the patients!

What do you do that ordinary vets may not?

In general practice, most vets can perform professional scaling and polishing, and extractions. While I still spend a lot of time extracting teeth (especially those big nasty ones), I can also offer alternatives that may save teeth, such as root canal therapy, periodontal surgery, and even orthodontics! People always ask whether we do braces for dogs and, yes we can, but not for purely cosmetic purposes. Any treatment we do is aimed at fixing issues that cause pain, infection or problems with eating.

Another big part of our service is dental radiology and imaging. About two thirds of each tooth is buried in bone, so xrays are very important tools in dental diagnosis and treatment. We also have in-house CT and MRI if needed.

An infected premolar post extraction.
What's involved in a root canal and why would someone have it performed on their dog? Isn't it easier just to pull a tooth out?

A root canal procedure is most commonly performed on a tooth that has been fractured or damaged, and the pulp tissue (living tissue inside the tooth) has died. Basically, it involves removing all of the dead and infected material from the root canal inside the tooth, filling the tooth with a material that stops bacteria from resettling inside the canal, and sealing the tooth with a filling.

While root canal surgery has a bad reputation in people, it is not as stressful for our patients, as they are anaesthetised and we aim to do it in one procedure (in humans it usually takes multiple visits, but we do it in one stage to minimise the number of anaesthetics needed). Almost all patients are home within a few hours, and eating the same day as if nothing has happened.

Extracting a dead or damaged tooth is always a better option than leaving it to rot in place. However, root canal treatment can be a lot less invasive and allows the animal to keep the function of the tooth. For smaller teeth, this may not be as important (unless the animal is a show animal or working dog). The main teeth we treat are the big canines (fangs) and carnassials (large cutting teeth). The root of the lower canine, for example, makes up more than half of the front of the lower jaw, so extraction is a big deal!

While no tooth is critical in a pet living in modern society (as long as we do the food hunting for them of course!), preserving teeth allows better function (for example, the canine teeth are a dog’s equivalent of an opposable thumb), and can help avoid complications of extraction such as jaw fracture, tongue drooping and lip damage.

Delicately suturing an oronasal fistula in a microdog.
What sort of conditions do people refer to you?

I see all sorts of things, including broken teeth needing root canal treatment, bite abnormalities needing orthodontic intervention, oral tumours, fractured jaws etc. While some hospitals now have dental radiology, those that don’t may refer patients in for xrays to allow better diagnosis and treatment of dental problems.

Often vets will refer in cases that need a lot of teeth extracted (such as severe periodontal disease or gingivostomatitis) as I am a pretty fast surgeon, so the time under anaesthesia can be greatly reduced. This is particularly important for patients with other conditions such as heart or kidney disease, where the risks with anaesthesia are higher.

I see a lot of puppies with bite abnormalities, as we can sometimes intervene and improve their development when they are young and still growing. Sometimes I will also help when there has been a difficult surgery, for example if a tooth root is difficult to extract, or there have been unexpected complications. I love a challenge!!

Do you ever get sick of teeth?

No. Not a bit. Never. Scary, huh? Maybe I should get out more….

Why do we so often underestimate dental pain in animals?

Animals are so good at hiding dental pain. Dental disease is hidden in the dark, inside the mouth. While an animal may not be able to hide a limp, it can always chew on one side, or swallow food whole, and this can go unnoticed for months or years. Dogs and cats can suffer extraordinary dental disease before they get to the point of not eating – they will soldier on until the prospect of starving to death is preferable to the pain of eating.

Do you have any tips around dentistry for vets and vet students?

Always look in the mouth – don’t expect pets to tell you, or their owners, that they have dental issues. Plan your dental surgeries, such as extractions, with the same consideration as you plan other surgeries – lack of planning is the biggest reason dental disasters occur. Dental radiographs are SO important for diagnosis and treatment planning – about two thirds of each tooth is buried in bone, so without xrays you are truly operating in the dark. Use good quality, sharp instruments. Finally, have patience - this is a lifelong learning exercise, but it pays off.

Thank you Dr Hawke! If you're seen for more dental tips, Dr Hawke will be running a workshop through the Centre for Veterinary Education in May (read more here) and will also be speaking at the AVA 2014 Annual Conference (registration here).