Tooth pulp inflammation in dogs

Overview

Inside the tooth

Pulp contains blood vessels and nerves. It extends from the visible crown into the root canal. Enamel is the hard outer crown covering. Beneath it lies dentine. Living pulp also forms dentine internally. This gradually narrows the canal during maturation. Dead pulp no longer produces dentine. Vessels and nerves enter through small root-tip openings. Damaged circulation has no alternative vascular network. Mild injury-related inflammation can resolve with surviving pulp. Severe injury can make inflammation irreversible.

Causes

Fractures, impacts and wear

Deep crown fractures expose pulp to oral bacteria. Fractures confined to dentine can still allow bacteria along microscopic tubules towards pulp over time. Strong impacts can damage blood supply without chipping the crown. Vascular injury can inflame pulp. Prolonged chewing of hard or sandy objects wears protective layers. Slowly wearing teeth can develop brownish reparative dentine. Deep cavities can reach pulp. Dental caries is relatively uncommon in dogs. Advanced periodontal disease can reach the root tip and damage pulp. Enamel developmental defects can permit bacterial access to inner tissues.

Risk factors

Young permanent teeth have relatively large pulp cavities and thin dentine walls. They fracture more easily than mature teeth. Bones, antlers and hard toys increase fracture risk.

US military dog examinations found at least one dental injury in 596 dogs, or 43.6%. Pulp exposure occurred in 647 damaged teeth, or 59.9%. Incisors and canines were susceptible to pulp-exposing fractures. Cause was unknown for 448 exposed fractures, or 69.2%. Bite work caused 41, or 6.3%, in the same group. Malocclusion can make an opposing tooth contact and damage an upper canine.

Typical symptoms

Dental pain can alter how food is taken despite normal overall intake.

• Chewing more often on only one side.
• Avoiding hard treats or chew toys.
• Increased drooling.
• A red or black spot in a broken tooth's centre.
• One tooth becoming pink, purple or grey.
• Swelling of the cheek on the affected side.

Chewing tenderness may cause reluctance to hold toys. Cold water can hurt exposed pulp. Pink discolouration can turn brown or grey as internal blood breaks down. Some dogs approach food but leave it through pain. Internal discolouration can follow impact despite intact enamel. Among 102 intrinsically discoloured teeth, 55 had no crown damage, or 53.9%.

Complications and consequences

Pulp death and root infection

Untreated inflammation can cause pulp necrosis. Bacteria reaching the root tip can form a tooth root abscess.

An infected large upper chewing tooth can drain through skin below the inner eye corner. Upper canine abscesses can swell the muzzle's side. Abscesses can also drain into the mouth as a red, discharging opening near the tooth. Pain can return in a dead tooth when root inflammation develops.

Deciduous root infection can damage the developing permanent tooth. Later enamel defects can result. The damaged permanent tooth may also fail to erupt.

Diagnosis at the vet

Examination and dental X-rays

Awake examination can identify visible fractures and malocclusion. Detailed assessment requires general anaesthesia. Health is assessed beforehand, with blood samples when needed. Dental X-rays assess crown-to-root extent. Inflammation can appear as darker bone around the root tip. Dead pulp may leave a wider canal than the opposite corresponding tooth. Inflamed pulp can sometimes produce dentine faster, narrowing the canal. Dental charts record mobility and surrounding pocket depths, among other findings. X-rays can check retained roots when a tooth appears missing after trauma.

Intact-looking or discoloured teeth

Among 111 upper fourth premolar crown fractures without visible pulp, 27 had endodontic X-ray lesions, or 24.3%. None occurred in 500 unfractured control premolars. Histology found necrosis in 85 of 97 intrinsically discoloured teeth, or 87.6%. Twelve, or 12.4%, had pulpitis.

Endodontic X-ray findings occurred in 58 of 102 discoloured teeth, or 57%. All teeth with dark periapical areas had necrotic pulp. Nevertheless, 19 of 102 looked radiographically normal, or 18.6%.

Cone-beam CT can identify periapical bone changes missed by standard dental X-rays. Visible pulp exposure also influences treatment decisions. Inflamed teeth can still contain living pulp at examination.

Treatment

Preserving living pulp

Treatment depends on fracture extent, tooth development and time since injury. Partial pulpotomy removes damaged pulp while aiming to preserve living root canal tissue. Protective material covers apparently healthy pulp and the opening is restored. A young permanent root can then continue developing. Success is most likely with prompt treatment, ideally within 24–48 hours. Initial follow-up X-rays may be taken after three to six months.

One evaluation involved 190 teeth in 138 dogs. Treatment was successful or without evidence of failure in 162 teeth, or 85%. Success indicators included new dentine on follow-up imaging. Twenty-eight teeth failed, or 15%.

A later 68-dog study found success in 96 of 100 teeth treated for malocclusion, or 96%. Only two of seven fractured teeth succeeded, or 28.6%. Median time to final anaesthetised follow-up was 248 days.

Root canal treatment, extraction and monitoring

Root canal treatment removes all pulp contents. The canal is cleaned and filled with sealing material. A restoration blocks oral bacterial entry. Functionally important canines and large chewing teeth are often considered. Every canal in a multi-rooted tooth needs cleaning and filling. Extraction removes the source of a root abscess. With sudden facial swelling and delayed dental treatment, antibiotics can control infection beforehand. Definitive tooth treatment remains necessary despite reduced swelling. Deep subgingival fractures may require extraction. Advanced periodontal disease can preclude preservation. Pulp-exposing deciduous fractures are extracted.

Radiographic root canal outcomes were followed in 281 teeth from 204 dogs. Complete success occurred in 199, or 71%. Seventy-one, or 25%, had no failure evidence despite possible persistent prior root-tip changes. Eleven failed, or 4%. Mean follow-up was 437 days. Another study found 90.83% success in 120 fractured upper fourth premolars in small and medium dogs. Pre-existing periapical changes worsened prognosis in that group.

Prevention

Antlers, hooves and hard bones can fracture teeth, so softer toys reduce hard-chewing stress. Test flexibility by checking whether a fingernail indents the surface. Constant chewing of sandy tennis balls can wear teeth. Brushing may reveal chips before obvious pain. It reduces plaque that can cause periodontal inflammation. Gradual introduction from a few teeth in puppyhood makes habituation easier.

Important for dog owners

Record injury timing because it affects treatment options. Photograph damage only without forcing the mouth open. Stop hard chews until assessment. Follow the clinic's fasting instructions before anaesthetised dental care. Root canal-treated teeth need dental X-ray follow-up. Soft food may be advised for one to two weeks afterwards. Follow recovery instructions particularly on the anaesthetic day, when drowsiness can remain.

Frequently asked questions

Can dogs eat normally with dental pain?

Yes, even a painful fracture may not stop normal eating. The only change you notice may be that your dog chews food on the other side of the mouth. Some dogs avoid hard treats or chew toys they previously enjoyed. The painful tooth may also be sensitive when your dog drinks cold water.

What does a grey tooth mean?

Grey discolouration can come from inside the tooth after an impact damages the pulp blood supply. This colour change can be visible even when the crown remains intact. Dental X-rays can investigate whether there are signs of inflammation around the root. A tooth can look normal on X-rays even when its crown is clearly discoloured.

Why examine even a small chip?

Even a chip can expose small channels within dentine, allowing bacteria to travel towards the pulp. The vet assesses how deep the damage extends and examines the root area on dental X-rays. In some circumstances, a superficial lesion without inflammation can be treated with a sealant. Follow-up of the restored tooth can identify inflammatory changes developing later.

When can a fractured tooth be saved?

Permanent teeth can be considered if structure and attachment remain adequate. Recent injuries can sometimes retain living pulp through partial pulpotomy. Root canal treatment can sometimes preserve teeth with dead pulp.

Why repeat X-rays after treatment?

Images assess whether periapical inflammation shrinks after root canal care. After pulpotomy they also show continued root growth in young teeth. New or larger root lesions can indicate failure.