Dr. Andrea SteinmetzDr. Andrea Steinmetz is a specialist veterinarian for small animals with the additional title ophthalmology and for small animal surgery. She is head of the ophthalmology department of the small animal clinic at the University of Leipzig. She is also a member of the Dortmunder Kreis, the society for the diagnosis of genetic eye diseases.
Clinic for Small Animals of the University of Leipzig
Unilateral purulent eye discharge in dogs – what can be behind it?.
The Irish setter "Paul" is a cheerful dog who enjoys exercise. His left-sided purulent eye discharge, which he had been suffering from for several weeks, did not change that. Initially, conjunctivitis was suspected. However, the eye medications administered so far had not brought any improvement. Also an antibiotic, which was given after determination of an antibiogram (effectiveness test in the laboratory), alleviated the problem only briefly. Obviously, this was not a "simple" conjunctivitis.
The ophthalmological examination – the eye examination
In addition to the obvious watery-purulent eye discharge, "Paul" also had a mild swelling of the nasal lower eyelid. The entire conjunctiva and the area behind the third eyelid were searched thoroughly under local anesthesia with the help of special forceps, but without success, for a foreign body. During the examination with Slit lamp (light source with magnifying function) the cornea and the anterior interior of the eye were inconspicuous.
During the observation of the Tear spot (these represent the openings for the lacrimal fluid draining into the lacrimal duct) it could be seen that, especially with prere on the nasal lower eyelid area, the flow of pus had its source here. The secretion was originally "worm-like" here.
With a thin plastic cannula, the tear duct can usually be flushed well under local anesthesia. The animals tolerated it very well. With "Paul" it was different: only pus came out of the lower tear spot when flushing over the upper tear spot. Nothing at all drained through the nose and "Paul" was visibly uncomfortable with the procedure. So there was now the suspicion of a foreign body in the so-called lacrimal sac. A "simple" inflammation was considered improbable.
The tears and the nasolacrimal duct system
The lacrimal fluid is a very valuable substrate, which in the form of the tear film u.a. is of enormous importance for the nourishment, moisturization, care and transparency of the cornea. Its composition is complex – it is formed from the Lacrimal glands (in the dog two; an additional one at the third eyelid = aqueous portion), the goblet cells of the conjunctiva (mucous part) and the Meibomian glands at the eyelid margin (oily part) consistently reappears.
"Spent" or excess amounts are drained as rinsing fluid via the nasolacrimal duct system derived. This system consists of the two orifices (the lacrimal puncta), the two lacrimal tubules, a lacrimal sac located deep in the orbit where both tubules meet, and the duct itself, which initially runs in the inner bony portion of the nose. Thus, these structures are difficult to access from the outside. It is possible to visualize the nasolacrimal duct by filling it with a viscous contrast medium in X-rays or computer tomography. A contrast stop would indicate an obstruction.
The surgical therapy
In the present case, contrast imaging was not used. The danger of pushing a foreign body from the lacrimal sac into the even less accessible bony nasolacrimal duct would be too great. Surgical therapy was targeted instead. "Paul" had to be put under general anesthesia for this and positioned so that the area could be easily visualized under the surgical microscope. Pus drained. After extensive rinsing. A granule could then be removed from the lacrimal sac by suction. After extensive rinsing and suctioning, a granule could then be removed from the lacrimal sac.
In the further course, the Irish setter showed no more irritation symptoms or ocular discharge even without ophthalmic medication.
In case of purulent eye discharge and/or irritation symptoms (eyelid pinching, redness of the eye, itching) the animal should be presented to a veterinarian."
Purulent eye discharge in dogs
In fact, bilateral purulent conjunctivitis without another underlying disease (z.B. dry eye, systemic infectious diseases) are rather rare and can often be brought to healing without an antibiotic eye medication, for example with caring rinses. In case of persistence or. severe irritation, however, the cause must be clarified promptly.
Suddenly occurring unilateral eye discharge should always be reason for a prompt visit to the veterinarian, since here a foreign body can be the cause. Often, especially in the summer months, these are awns which, because of their shape, can get into the lacrimal sac and, more often, through the conjunctiva behind the eye.
While a foreign body trapped in the lacrimal sac "only" causes persistent ocular discharge, free migration of a granule past the eye into the orbit results in abscesses there, which put the eye and vision at risk. If a foreign body is removed in time, the symptoms heal quickly – and late effects are then not to be feared.