This article is dedicated to understanding Epiphora in dogs better.
Why do Dog Eyes Tear?
Tears function as a lubricant of dogs’ eyes to protect them from drying and any irritants. When tears overflow, it causes watery eyes. This is a condition known as epiphora in dogs, and it often is an abnormal ophthalmologic condition that requires treatment.
Common Signs and Symptoms Associated With Epiphora in Dogs
An evident sign of epiphora is watery eyes. This can be slight, moderate, or severe.
You may overlook a volume of tears in slight or moderate cases. This is especially true in breeds with certain traits and characteristics. Some examples are listed below.
- Long fur (e.g., Shih Tzu, Lhasa Apso, Maltese, Old English Sheepdog, etc.)
- Small eyes (e.g., Bull Terrier)
- Natural periocular folds (e.g., Sharpei, Neapolitan Mastiff, Bulldogs, Dogue de Bordeaux)
The severe case will likely have tears overfilling the eyes, causing wet damped fur surrounding the eyes. The damped fur is often visible with a reddish-brown coloration as a result of porphyrins.
Porphyrins are naturally occurring molecules that contain iron byproducts triggered by heme biosynthesis (a breakdown of red blood cells). This is a part of the normal homeostatic process to remove iron-containing wastes out of the body system.
Having the porphyrins themselves is not harmful to the dogs, but it should not be leaking out so much to stain the fur.
The affected dogs may also experience other symptoms, such as squinting or frequent blinking, ocular inflammation (red eyes or conjunctivitis), periocular inflammation (eyelid swelling), irritation/pruritus, corneal ulcers, ocular discharges (mucus, transparent, crusty), and/or nasal discharge (mucus, transparent, crusty).
There may be changes in demeanor and general behaviors. For example, the affected dogs may be quieter than usual, perhaps restless or winning frequently. In addition, they may suffer from low visibility /decreased vision, leading to reduced appetite and water intake.
Moreover, the dog may not want to participate in their usual daily routine due to visual impairment and discomfort.
What are the Causes of Watery Eyes in Canines?
Epiphora in dogs is a result of either excessive tear production or insufficient tear drainage.
The tears are produced in the lacrimal gland in response to a neural reflex on lacrimal nerves. Excess tears travel through nasolacrimal ducts with openings located in the eyelids near the nose (one in the upper eyelid and one in the lower eyelid) to be drained out the nose and mouth.
A central stimulant of the lacrimal nerves is the irritation on the ocular surface. Irritation can be caused by a number of different issues, including conjunctivitis, nerve injury, trauma, pain, foreign bodies, allergic reaction, chemical/smoke exposure, entropion/ectropion, blepharitis, glaucoma, uveitis, and distichiasis.
Constant exposure to the aforementioned stimulant/s can lead to excessive production of tears.
In rare cases, some dogs possess overactive lacrimal glands or excessively large lacrimal glands that may cause an overproduction idiopathically without an influence of the stimulants.
Congenital defects like shallow eye sockets (common in poodles, bichon frises, and brachycephalic dogs), traumatic scarring, foreign bodies, infection, inflammation, and Cherry Eye (a prolapsed nictitating membrane) are some of the conditions that can affect the patency of the lacrimal passage.
How is Epiphora in Dogs Diagnosed?
A comprehensive ophthalmic examination, fluorescein dye staining test, and Schirmer Tear test are commonly performed simultaneously by veterinarians during a consultation to identify visible symptoms and their severity.
These examinations are generally performed while the affected dogs are conscious and rarely need to have them sedated or put under anesthetics.
The ophthalmic examination involves a magnified analysis of the eyes, eyelids, and other associated regions using the ophthalmoscope.
The fluorescein dye applied on the cornea will be visible from the nostrils after several minutes in the functioning nasolacrimal ducts. The stain will adhere to any damaged area on the corneal surface and turn the area bright green when exposed to the cobalt blue light.
The Schirmer Tear test measures the production of tears. The special filter paper strip is inserted in the lower eyelid to let the moisture travel along the length of the strip. The result is measured after a minute to confirm the secretion rate.
Advanced imaging such as radiography, CT scan, scintigraphy, and endoscopy may be required to further investigate the lacrimal passage and surrounding organs and structures.
A combination of the relevant history, clinical findings, and diagnostic results will confirm the diagnosis of epiphora.
Effective Treatments in Combating Runny Eyes in Dogs
The treatment of epiphora varies depending on the underlying condition (excessive tear production or dysfunctional lacrimal passage). Therefore, the effective treatment is to treat the cause of the underlying condition.
Treatment options may be as simple as dietary changes or antihistamine to prevent an allergic reaction, course of antibiotics or antivirals to treat any associated infections, anti-inflammatory medication to treat inflammation, and/or unblocking the duct by manually flushing.
In some cases, the aforementioned options may not be applicable or ineffective. Then, a more intensive approach like a surgical intervention of the causal aspect may be required to resolve the condition. Examples are neoplasia, foreign bodies, and congenital defects.
Nasolacrimal duct surgery is required for blocked/non-patent ducts. The surgery may involve repairing the duct opening by removing the causal tissue or foreign bodies and widening the passage.
Another option to repair the ducts is Dacryocystorhinostomy. Dacryocystorhinostomy is a procedure to surgically create a complete new lacrimal passage.
Entropion (inward turning of the eyelids), ectropion (outward turning of the eyelids), cherry eye, and abnormal growth (i.e., tumors, pterygium, etc.) within the ocular region may be repaired surgically to relieve pressure, pain, and itchiness.
For long eyelashes that negatively impact the eyes, surgical trimming or electrolysis (removal of hair roots) may be required to relieve the discomfort and irritation.
How Can Epiphora in Dogs be Prevented at Home?
We all know prevention is better than cure and a regular veterinary check is an essential part of this, but what can we do at home to minimize the risk of our dogs getting epiphora?
Educate yourself and everybody that is involved in your dog’s care. It is essential that all of you have a clear understanding of the condition and are on the same page about what needs to be done at home to prevent epiphora, or in fact, any disease.
Daily check of your dog. No pet owner goes a day without spending time with their animals, and it certainly is common sense and is second nature to the owners. However, we still want to emphasize the importance of this daily ritual. It can detect any change or abnormality, even something very subtle. This leads to early detection and treatment.
It is vital to maintain good ocular hygiene. Clean the face regularly to keep it clean and free of dust, dirt, foreign bodies, and any possible contaminants.
There are many commercially available facial cleansing products for dogs, but some products’ chemical components or active ingredients may not suit your dog. Therefore, it is vital to make sure that you are using the ingredients that are dog-safe, veterinary-approved, and anallergenic for your dog.
We advise you to discuss with your veterinarian first to decide on a cleaning approach before jumping into the gun and starting home care.
Also, avoid exposing your dog to any stimulus that has been identified or known to be a risk factor. This may be difficult to achieve before developing epiphora, but it certainly is a measure that should be taken to prevent a recurrence.
Alianna graduated Massey University with a Bachelor of Veterinary Technology degree in 2015. She moved to Australia in 2016 to pursue her passion in reptiles and exotic animals and has been working as a veterinary technician/nurse in an exotic animal veterinary clinic. Since moving to Australia, she has gained several qualifications including advanced veterinary nursing of reptiles and amphibians, advanced veterinary nursing of Small mammals, and venomous snake handling. She is a big advocate of continual education and learning, and has presented at conferences including VNCA conference, AZVT (American Zoological Veterinary Technician) Conference, and UPAV (Unusual Pets and Avian Veterinarian) conference. Veterinary medicine and welfare of aquatic, herpatological, invertebral, and Australian fauna species are her special interests.