Secondary Sinusitis
Have you ever seen a horse with thick, smelly, discharge from one nostril? The most common cause of a one-sided nasal discharge is a sinus infection (sinusitis).
A horse with sinus disease may show any of the following signs: a one-sided nasal discharge of thick white or yellow pus or mucus, blood, or a distinctive unpleasant odor from one nostril.
The horse has several sinus cavities, three of which are the ventral conchal, and rostral and caudal maxillary sinuses. The roots of some of the upper molars lay in these sinuses and are only separated from the sinuses by a thin sheet of bone. These teeth can develop an infection that travels into the sinuses, which is called secondary sinusitis. Secondary sinusitis means a sinus infection caused by another problem, such as a tooth infection, periodontal disease, cyst, or mass. The most common cause of secondary sinusitis is a dental infection. Primary sinusitis is caused by a bacterial or fungal infection without a secondary cause.
A horse with sinus disease may show any of the following signs: a one-sided nasal discharge of thick white or yellow pus or mucus, blood, or a distinctive unpleasant odor from one nostril.
The horse has several sinus cavities, three of which are the ventral conchal, and rostral and caudal maxillary sinuses. The roots of some of the upper molars lay in these sinuses and are only separated from the sinuses by a thin sheet of bone. These teeth can develop an infection that travels into the sinuses, which is called secondary sinusitis. Secondary sinusitis means a sinus infection caused by another problem, such as a tooth infection, periodontal disease, cyst, or mass. The most common cause of secondary sinusitis is a dental infection. Primary sinusitis is caused by a bacterial or fungal infection without a secondary cause.
Left untreated, these infections can become quite serious. With time, the sinuses can become filled with fluid, inspissated material, and even food. Antibiotics may temporarily clear up the sinus infection, but because bacteria can hide inside the tooth despite long courses of antibiotics, once the antibiotics are discontinued, the sinus infection will return. This type of sinusitis can be complicated to treat. Antibiotics alone will not cure a sinus infection caused by a diseased tooth, the infected tooth must be extracted.
An oral examination, endoscopy and radiographs will help to confirm a secondary dental sinusitis. Regular dental exams by a veterinarian can often catch infected teeth or periodontal disease before they cause a sinusitis.
An oral examination, endoscopy and radiographs will help to confirm a secondary dental sinusitis. Regular dental exams by a veterinarian can often catch infected teeth or periodontal disease before they cause a sinusitis.
As you can see on this CT image, the sinuses should be black - showing that they are empty (filled with air). However on the left side of the CT image you can see a tooth with an apical infection and a surrounding gray area - showing that the sinus is filled with material. When a sinus infection progresses this far, removing the infected tooth may not be enough to clear up the sinus infection. These horses might also need a sinus surgery to remove the inspissated material, as well as antimicrobial treatment.
If your horse has smelly, one-sided nasal discharge, it is highly recommended that you have a veterinarian out to do an oral exam and take radiographs to evaluate the health of the teeth.
If your horse has smelly, one-sided nasal discharge, it is highly recommended that you have a veterinarian out to do an oral exam and take radiographs to evaluate the health of the teeth.