Tooth Root Abscesses in Horses

Key takeaways

Tooth root abscesses are infections occurring at the base of the tooth, known as the root in horses.

  • Infections in this area often affect the surrounding bone, ligaments, and in the case of upper teeth, the sinuses can become infected
  • Common symptoms of tooth root abscesses include foul smelling breath, swelling on one side of face or jaw, decreased appetite, weight loss, and indentations or weeping sores on the upper or lower jaw
  • Diagnosis involves an oral exam and diagnostic imaging
  • The condition is most commonly resolved by extraction of the affected tooth or teeth, combined with antibiotic treatment
  • The prognosis is good with prompt treatment in most cases
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A closer look: Tooth Root Abscesses in Horses

Tooth root abscesses are also referred to as tooth root infections or apical infections.

Tooth root abscesses are a common dental condition in horses, but are avoidable with routine dental care and easily resolved when they do occur. Prompt veterinary assessment is encouraged to prevent the infection from spreading.

Risk factors

Abscesses occur in horses of any age, but are more common in younger animals. Commonly, cheek teeth are affected. Newly erupted teeth in young horses are at higher risk of infection due to the increased blood flow and inflammation. Prognosis is good when treated promptly by a veterinarian.

Sinusitis is a common secondary condition when the abscess is in the upper teeth, due to the close proximity to the nasal cavity. If sinusitis is present in conjunction with the abscess, prognosis is poorer than with a dental abscess alone, but still good.

Possible causes

Causes of tooth root abscesses include dental fractures, overcrowded teeth, and gaps between teeth. The most common causes are blood-borne infections. In these cases, infections travel from other parts of the body and settle in the tooth root, causing a tooth abscess as a secondary condition.

In addition, generalized symptoms of oral discomfort may be present. Examples include

  • Resistance to rein contact under saddle
  • Head shaking when bridled
  • Reluctance to consume feed that is cold or hard
  • Presence of uncrushed/improperly chewed grain in feces
  • Pausing during chewing

Testing and diagnosis

Diagnostic tests on horses are commonly performed under sedation, although certain animals may require general anesthesia due to temperament.

Diagnostic tests include:

  • Physical examination
  • Oral examination
  • Diagnostic imaging, including X-rays, CT, or bone scans

Steps to Recovery

Treatment commonly includes;

  • Extraction of affected teeth under sedation or anesthesia, depending on severity
  • Insertion of a plug and antibiotics into empty tooth socket, which is removed after 2 weeks
  • Antibiotics
  • Anti-inflammatories

If secondary sinusitis is present, treatment may also include;

  • Sinus lavage after tooth extraction
  • In severe cases, sinus trephination (surgical formation of a hole or flap in the sinus) may be required for adequate drainage and treatment

Tooth root abscesses are commonly resolved by tooth extraction, with a follow-up veterinary appointment to confirm the extraction was curative. Managing dental issues quickly is important to ensure ideal outcomes by preventing progression to adjacent structures.

In rare cases, untreated or severe cases of sinusitis can lead to bacterial meningitis. Bacterial meningitis is an infection of the membranes surrounding the brain and spinal cord, and is often fatal.


Tooth root abscesses are preventable with routine dental and veterinary care, including annual or semi-annual dental floats. The frequency of floating depends on the horse’s age and living conditions. Horses younger than 5 years of age and senior horses require more frequent floats to maintain their dental health.

Are Tooth Root Abscesses in Horses common?

Tooth root abscesses are an avoidable, yet common, dental issue. The most commonly affected teeth are the cheek teeth located in the back of the mouth, composed of the molars and premolars. Abscesses can occur at any age, but are more common in younger horses. In cases where the upper teeth are infected, sinusitis is a common secondary condition.

Typical Treatment

Treatment typically includes removal of the affected tooth or teeth.

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