Our clients often seek advice on how to treat the messy, frustrating problem of tear staining. If you research “tear staining”, you will find numerous different products, ideas, and suggestions that claim to fix or prevent the staining. The fact that there are so many products available means that there is not ONE magic treatment or approach that will work for every dog.
The red/brown discoloration in tears comes from porphyrin. Porphyrins are iron containing molecules produced when the body breaks down iron. Porphyrins are excreted through the gastrointestinal tract, urine, saliva, and TEARS! All dogs have some porphyrin in their tears, but some dogs have more porphyrin and the staining is always more noticeable in white or light-colored dogs.
A common misconception about tear staining (Figure 1) is that it is due to excessive tear production. Most dogs with tear staining have normal tear production and do not have an underlying ocular problem. However, many dogs have a normal variation in their eyelid conformation that causes tears to drain onto their face rather than draining down the nasolacrimal puncta and into the nasolacrimal system.
There are three common variations in eyelid conformation that cause tearing onto the face rather than down the nasolacrimal system. They include:
Figure 2. Medial canthal trouging and haired caruncle in a dog.A medial canthoplasty is a surgical option to reduce tear staining in some dogs with these types of eyelid conformations. Cryotherapy can be used to treat a haired lacrimal caruncle. However, in most dogs neither procedure is warranted. Any ocular irritation in a dog with any of these variations in eyelid conformation will cause more than the typical tear staining. Allergies, teething, corneal ulcer or other ocular disease may be the culprit.
Some treatment options for dealing with tear staining in dogs include:
Dogs with tear staining should be evaluated to rule out an underlying ophthalmic problem that requires specific treatment. If the tear staining is secondary to conformation, the treatment plan should be an educational discussion focusing on proper cleaning and grooming. Referral to an ophthalmologist is appropriate to rule out underlying ocular disease and to discuss the possible surgical options.