Monday 29th of May 2023
Vet Advice

Equine nasal discharge: When a snotty nose isn’t just a snotty nose.

By Chris Neal, Towcester Equine Vets

Last year, we were called out to see a young horse that had a unilateral purulent nasal discharge present for about a week. New horses had come on to the yard in the last week, but they showed no signs of ill health and were fully vaccinated. She was bright, alert, had a good appetite and was working normally. No obvious swellings were noted, she had a normal temperature and a cough could not be elicited. For these reasons, infectious conditions like equine influenza and strangles seemed unlikely (usually cause dullness, inappetence and bilateral nasal discharge). She was therefore treated with a long course of antibiotics for a primary infectious sinusitis, a very common condition.


Things progressed well and the discharge cleared up quickly after starting the course of antibiotics. However, after 24hrs of the antibiotics finishing, the discharge came back. She was therefore admitted to the clinic to try to find the underlying cause of her sinusitis.


Firstly, we performed a complete oral examination, including placement of a gag and oroscopy (where a camera is placed into the mouth, allowing us to accurately image the surface of the teeth and check for decay).  These revealed no abnormalities, and so radiography was performed to check for fluid or swellings in and around the sinus.


These were initially a little unremarkable, however, when we enlarged the images we could make out the faint outline of a circular swelling in the rostral maxillary sinus, with a radiolucent middle – check the radiograph, its difficult to see! Based on this, we made a diagnosis of an encapsulated mass that was likely to be causing the sinusitis. This type of pathology in young horses is more often than not cystic, enabling us to make a provisional diagnosis of a paranasal sinus cyst.

 Diamond Calvert Sinus Cyst (1)

Diagnosis made, but we now had to remove it! A flap of bone was dissected away from the maxillary sinus, allowing us to accurately visualise what lay beneath. This could be done under local anaesthesia and nerve blocks with the horse conscious and standing in the stocks, minimising the risks of general anaesthesia. Low and behold, a large cyst was present that had to be carefully dissected away, ensuring no residue was left that could seed the formation of another one. This took time, but after a couple of hours we were happy that it was removed and the sinus and bone could be reconstructed. A head bandage was placed and a catheter sutured directly into the sinus allowing us to flush out any remaining infection for 5 days post surgery.




The horse made an amazing recovery, and was back out on the cross country course within a couple of months of surgery. She has had no further nasal discharge and a very happy owner! Although this is rare, this case shows a snotty nose doesn’t have to mean infection, and there are many other causes out there like this one that can cause it. Careful examination and an accurate history from yourselves can lead us down the correct path and reach an accurate diagnosis. 


NEWS: Due to increasing demand the Towcester Veterinary Centre Group have opened a new clinic at Onley Grounds Equestrian Complex, Rugby. In line with the expansion of this leading equestrian complex, clients in the north of the practice can now benefit from a local veterinary centre with four day boxes, spacious, examination room, indoor school and outdoor trot-up and lungeing areas.

The facility is also available for the treatment of horses competing at the complex and the purchase of non prescription drugs and disposables such as bandages, wound creams and feed supplements. Visit for more information.


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