Treatment of sinus infections in horses

At first, the eight-year-old eunuch noticed small discharge from the nose. It comes from the left nostril and smells a bit unpleasant. Harmless, the owner thinks and wants to wait and see; Perhaps the discharge will clear up on its own. He does not do this, on the contrary: after a few days, the secretion is still bleeding from his nose. Additionally, the chestnut welder began hitting his head both while riding and at the grooming station. The owner calls the vet. Its diagnosis is not harmful: the testicle suffers from sinusitis, that is, inflammation of the sinuses associated with the teeth.

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Sinusitis in horses: diagnosis and treatment

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Interesting facts about anatomy

There are a total of seven paranasal sinuses in horses – two of which are the maxillary and frontal sinuses, which are the most common in inflammation. The sinuses are air-filled extensions of the mucous membranes (called alveoli) from the nasal cavity. “The maxillary sinus consists of an anterior and a posterior sac. The posterior sac is connected to the frontal sinuses,” explains veterinarian and dental specialist Sigrun Klose. The sinuses are connected to the middle meatus through an opening. So diseases of the nasal mucosa can easily spread to the sinuses. It is no different with humans.

On the other hand, the mucous membrane of the sinuses is well supplied with blood. On the other hand, the openings between the nasal passage and the sinuses are very narrow; Therefore, accumulations of exudate (such as pus in case of infection) can quickly occur here.

The horse’s maxillary sinus is accessed from the middle nasal meatus. Here in the upper jaw are the roots of a total of twelve molars (another twelve molars in the lower jaw), which are surrounded only by a thin layer of bone (alveolar) at this stage.

What causes sinusitis in horses?

Sinusitis is either primary or secondary. The primary inflammation is caused, for example, by bacteria or fungi (see also “Other causes” section). Secondary sinusitis is more common. In rare cases, it is caused by tumors in the paranasal sinuses. Diseases of the nasal mucosa often spread to the paranasal sinuses.

If the inflammation originates in the upper molars, it is referred to as odontogenic sinusitis. Molars grow up to the age of six, and then are four inches long. Abrasion is one to three millimeters per year; This is how far the teeth are pushed. The dilemma: there is only a small space between the root of the tooth (Appex) and the sinus.

If a tooth becomes inflamed, for example due to tooth decay or in the form of gum disease (ie gingivitis), this can lead to an infection. Crown fractures due to poor stress distribution (due to inadequate dental examinations) can cause inflammation. If these rise above the root of the tooth and attack it, it can also affect the adjacent sinuses if dental problems are not detected in time.

In principle, horses of any age can develop sinusitis. However, animals up to 15 years of age, whose teeth are still relatively long, are especially vulnerable. Their roots are still very close to the maxillary sinus.

How can sinusitis be observed in horses?

It is difficult to identify toothache as a cause of sinusitis because horses can hide it for a long time. Sigrun Klose says that some animals start hitting their heads at some point or suddenly become unscathed. Unridable means: “In such cases, they defend themselves against the knight’s hand, and, for example, they can no longer be properly positioned.”

sinusitis summary

Lisa Radlin

Increased head banging and bad riding can be signs of sinusitis.

Changes in eating behavior, such as chewing more slowly than usual or food falling out of the mouth, also indicate early dental problems. “This should be checked immediately and carefully,” says veterinarian Sigrun Klose.

Unilateral nasal discharge, usually purulent and with an unpleasant odor, is typical of dental sinusitis. In addition, the enlargement of the lymph nodes in the jaw area on one side also indicates the disease, and is often associated with fever.

sinusitis summary

Lisa Radlin

Especially if there is also one-sided nasal discharge.

Sometimes there are also small, hard bumps in the maxillary region: if the disease is particularly bad, then the inflammation causes swelling of the tissues of the jawbone, which is called edema, explains Sigrun-Klose.

How does a vet make a diagnosis?

It is not easy. In order to correctly diagnose the disease, “real investigative work” is required, says Sigrun Klose. Clicking on the skull in the sinus region can actually provide initial insights. This is where the sound comes in: Normally, healthy sinuses fill with air and appear hollow. However, if it has liquid (such as pus) in it, it looks somewhat faint when tapped.

The second step is a comprehensive examination of the oral cavity and an endoscopic examination of the nasal passages and paranasal sinuses. Detailed x-rays are also taken of the affected area. In this way, it is possible to observe whether the roots of individual teeth are diseased and whether there is fluid in the sinuses.

sinusitis summary


Then you should definitely do an examination of the teeth and oral cavity.

“If the teeth responsible for sinusitis cannot be determined with certainty, a computer tomography (CT) scan is necessary.” This happens in the clinic. But in the head region, explains Sigrun Klose, the horse does not need general anesthesia, since a CT scan is performed on the anesthetized standing horse. The procedure is not cheap: about 1,000 euros is due here for each examination.

How do vets treat sinusitis in horses

The following applies to treatment: no experiments, the tooth must come out! The veterinarian Klose asserts that “treating him with medication alone is of no use.” “Because then it will only take a few weeks or months and new inflammation will form again.” The appropriate antibiotic is given anyway, and the vet also administers anti-inflammatory drugs to reduce the swelling of the mucous membranes.

For this purpose, the sinuses are cleaned endoscopically through the nasal entrance. If you cannot reach the sinuses through your nose to rinse them, a so-called burrow must be performed. For this purpose, a hole is drilled in the skull at the appropriate point on the outside, allowing external irrigation.

Either way, the horse should definitely go to the clinic for a few days, just because it needs to be washed twice a day. The horse should also be fed off the ground during this time so that the pus and secretions can drain. Skull injuries heal within about a week and a half.

How can you prevent sinus infections in horses?

The realistic answer: Barely. But healthy teeth are the answer and the end, and so regular dental checkups are essential, even for young horses. In this way, changes can be detected and processed in a timely manner.

If this is no longer possible, a decayed tooth should be treated by a dental professional or extracted. It is also important to respond in time to periodontal disease.

sinusitis summary


In the case of sinusitis, the treatment is straightforward: the diseased tooth must be removed, otherwise the next infection will soon follow.

Horse owners can also contribute to ensuring that dental health is “at risk” from the outside as little as possible by feeding them appropriately for the species. Hay, straw or grass is good for teeth. On the other hand, meals that contain sugar, such as muesli or foods high in molasses, can lead to food-related tooth decay. So Sigron advises Klose not to “handle every right step”.

other reasons

No matter how they are kept and fed, bacteria in the bloodstream also cause sinusitis. This is caused by a temporarily weakened immune state. A fungal infection can also lead to sinusitis. Primary inflammation of the paranasal sinuses (primary sinusitis) can be successfully treated with antibiotic therapy alone, since often the accumulation of exudate must be removed by additional therapeutic measures (rinsing the sinuses).


sinusitis summary

Sigrun Klose runs his veterinary clinic in Hagen, near Bremen. Among other things, Klose specialized in equine dentistry. She is an IGFP Certified Equine Dental Practitioner. Her other areas of expertise include hoof disorders and chiropractic.

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