Updated November 28, 2020
Sometimes when a tooth needs removal, there’s plenty of time to explain why. However, most of the time, you get a hurried phone call while your dog or cat is asleep. There’s really nothing you can do but trust us.
Let’s pull back the curtain. Here I want to show you, using the latest best practice guidelines, how vets decide when a tooth should be extracted (never pulled), and what your choices are.
We’ll look at each of the reasons why a tooth might cause enough pain to require extraction.
Tooth fracture is most commonly caused by chewing on hard objects such as antlers, fences, stones or even raw bones. While shallow fractures can be tolerated, those that involve the the tooth’s central pulp cavity require urgent care.
You can see a picture of an exposed pulp cavity at the start of our page on What to expect after tooth extraction. There’s also a discussion of costs of removal.
Such a tooth is destined to die, and then form a tooth root abscess. They can be below the eye like the one pictured here, or hidden in the jaw like the xray at the start (green arrows). These teeth always cause severe and ongoing pain, even if your dog appears normal.
General Rule: tooth fracture involving the pulp cavity requires immediate pain relief and either referral for root canal endodontics, or removal. Removal is a practical and low-cost option chosen by most owners..
Tooth resorption is the most common cause of tooth loss in cats, but it’s increasingly being seen in dogs too. Despite being everywhere, we still know very little about why it happens. It occurs when the tooth is invaded by special bone-destroying cells called odontoclasts.
Resorption below the gumline is probably painless. However, when it spreads or starts higher up, it causes painful cavities called odontoclastic resorptive lesions. You can sometimes identify these by red areas where gum is growing into a hole on the tooth.
The xray at the start shows the appearance of Type 2 resorption (red arrow), as seen by a loss of both the internal structure of the root and the periodontal ligament (the dark line on the adjacent good roots indicated by the yellow arrow).
General Rule: part or all of a resorbed tooth must always be removed.
- Type 1 resorption requires complete removal of the tooth including its roots as they remain intact and will not resorb by themselves.
- Type 2 resorption only requires removal of the part above the gum line. Attempting to remove roots in such cases is extremely difficult, as well as unnecessary.
Buildup of plaque on the teeth causes infection and damage to the periodontal ligament that holds the tooth in its socket. We call this process periodontal disease (PD).
As attachment is lost, the tooth becomes mobile, or even wobbly. Eventually it causes too much pain to be used.
General Guideline: a tooth should be removed when movement in any direction (other than axial) is greater than 0.5 mm.
PD in multi-rooted teeth, which is most of them, will eventually expose the junction between the roots. We call this the furcation. Once it’s exposed, food and plaque accumulate underneath the tooth and cause painful infection.
General Guideline: a tooth should be removed when a probe can be passed in one side of the furcation and out the other. In other words, when there’s a hole under the tooth.
The loss of attachment caused by PD also causes pockets to form between tooth and gum (‘3’ on the diagram). Once the pocket gets deep enough, food and plaque accumulate and the pocket gets harder and harder to manage.
General Rule: pockets deeper than 6 mm in dogs, or 4 mm in cats require advanced care. Most teeth like this are removed, and that’s a valid approach given the poor outlook. The ideal is periodontal flap surgery, but this is rarely available outside specialists. A bare minimum is cleaning under anaesthetic at least every 6 months.
Management of the pockets is one of the most important parts of a routine scale and polish. I hope you can see that it’s completely impossible to do with anaesthetic-free dentistry.
There are only two other common situations where tooth removal is indicated. The first is in cats with severe gingivitis and stomatitis, where even healthy teeth are sometimes removed to reduce the disease burden. The second is preventative extraction of puppy teeth that haven’t fallen out by themselves. You’ll find a whole article about this (and pictures!) at the link.
In closing, I can promise you something with my whole heart: your vet would always rather a clean mouth than a dirty one, and a dental procedure without extractions. The advice I give you on cleaning teeth in dogs and ways to keep cats’ teeth clean is designed to prevent you ever being in this position.
The reality is though, that in a long life nearly all pets need at least one tooth taken out. I hope this helps you for when the time comes.
By Andrew Spanner BVSc(Hons) MVetStud, a vet in Adelaide, Australia. These blogs are from a series regularly posted on email and Twitter. Subscribe via email here to never miss a story!
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