Epiphora in Dogs
Epiphora is a condition that causes an abnormal overflow of tears. Causes of epiphora due to the shape of the eyes is seen in many breeds. The overproduction of tears can be congenital due to distichiasis – turning in of the eyelashes, or entropion – the turning in of the eyelid. Young shelties, shih tzus, Lhasa apsos, cocker spaniels, pekingese, bulldogs, dachshunds, and miniature poodles are most commonly affected with distichia. Entropion is most commonly seen in some Chinese shar peis, pugs, mastiffs, poodles, Labrador retrievers and chow chows. The upper or lower lid may be affected. This condition may occur secondary to eye irritation.
Symptoms and Types
Epiphora is evident with the observation of an overflow of tears, tear drainage and/or staining on face. Other signs include:
- Redness and irritation
- Discharge from eye
- Ulcers of the cornea
- Skin around eye is loose or sagging
Congenital abnormalities include the occurrence of too large an opening of the eyelids, causing increased exposure of the eyeball in brachycephalic breeds. Ectropion, a turning outward of the eyelid, is commonly found in Great Danes, bloodhounds, and spaniels. Entropion is seen at birth in some breeds and can be acquired due to post-traumatic eyelid scarring and facial nerve paralysis.
Conditions acquired by a dog can lead to epiphora. These conditions include rhinitis/sinusitis, which causes swelling adjacent to the tear drainage system; trauma or fractures of the bones in the face; foreign bodies in the eyes (e.g., grass, seeds, sand, parasites). Tumors of the third eyelid, the conjunctiva of the eye, eyelids, nasal cavity, maxillary bone in the face, or in the sinuses located around the eyes will also be considered. A condition which causes the nasolacrimal duct (tear duct) to be obstructed, whether through inflammation due to an acquired condition, or because of a congenital abnormality, may also cause an overflow of tears.
Blockage of the nasolacrimal drainage system can be caused by congenital lack of normal openings on the eyelids into the tear drainage system, as seen in cocker spaniels, bulldogs, and poodles. Extra openings can also form into the tear drainage system in abnormal positions, such as openings along the side of the face below the corner of the eye, closest to the nose. Other possibilities include lack of openings from the tear drainage system into the nose.
Acquired conditions involving corneal or conjunctival foreign bodies are seen usually in young, active, large-breed dogs. Inflammation of the eyelids and conjunctiva can be due to infectious or immune-mediated causes. Disorders of the cornea are characterized by the presence of scratches/ulcers with or without inflammation. Inflammation of the front part of the eye, including the iris, can be present. Glaucoma is a condition in which the pressure within the eye is increased. Eyelid tumors are typically seen in older dogs of all breeds.
Your veterinarian will perform a thorough physical exam on your pet, taking into account the background history of symptoms and possible incidents that might have precipitated this condition.
Your veterinarian may order radiographs to check for lesions in the nose or sinus area, and contrast material may be used to help differentiate structures. Your doctor may also order a magnetic resonance imaging (MRI) or computed tomography (CT) scan. In addition, a culture of the material in the eyes will be taken for laboratory analysis. However, surgical exploration may be the only way to obtain a definitive diagnosis. A flushing of the tear ducts may be sued to dislodge any foreign material.
If irritation is evident, your veterinarian may also employ the use of a fluorescein stain, a non-invasive dye that shows details of the eye under blue light, in order to examine the eye for abrasions or foreign objects.