What Causes Tear Stains in Chihuahuas?

Have you noticed dark-colored tear stains under your Chihuahua's eyes? Tear staining is a condition that's characterized by dark reddish-brown stains under the eyes. When a Chihuahua produces tears, those tears may drip below their eyes, creating these distinct stains.

Chihuahua with tear stains

Chihuahua with acute tear stains

Some owners disregard tear stains as being nothing more than an "aesthetic" problem with no real cause for concern. This is true in many cases, but in others it's a sign of an underlying problem. Turning a blind eye to what's causing your Chihuahua's tear stains could make the problem worse, or it could lead to other problems like a yeast infection. If you've noticed tear stains on your Chihuahua, you should follow the tips below to identify the cause.

Why Tear Stains are Reddish-Brown Colored

Tears are clear, so conventional wisdom should lead you to believe that tear stains are also clear, only revealing the color of the Chihuahua's fur. While the color of your Chihuahua's tear stains may vary, most are a dark reddish-brown. So, why aren't they clear instead?

Tear stains receive their characteristic color from compounds within them. A Chihuahua's tears are more than just water; they contain mucus, electrolytes, nutrients; and iron-containing molecules known as poryphyrins. It's these porphyrins that create reddish-brown stains through the process of oxidation, similar to the way in which iron and iron-based metal alloys rust over time. When tears drip down a Chihuahua's face, the iron reacts to light, moisture and air, creating this distinct color.

Normally, tear stains have a reddish-brown color (like rust), caused by the oxidation of porphyrins. If your Chihuahua's tear stains are brown with little-to-no red, it could indicate the presence of a yeast infection. Yeast infections are particularly common among Chihuahuas with tear stains because of the moist fur below their eyes. Yeast pathogens thrive in moist and warm environments, making tear-stained fur an ideal breeding ground. Owners can reduce the risk of yeast infection by cleaning and drying the fur below their Chihuahua's eyes.

Causes of Tear Stains

Chihuahua with tear stains

Up to 1 in 4 Chihuahuas develop tear stains

According to TheNest, 20-25% of all small dogs develop tear stains. While it can affect all dogs, short-nose breeds like the Pekingese, Maltese, Shih-tzu, pug and Chihuahua have a greater risk because of their shallow eye sockets. If a dog's eye sockets are too small or shallow, tears will spill out instead of being flushed through the tear ducts. Also, keep in mind that tear stains are more visible on dogs with a light-colored coat than a dark-colored coat.

Aside from the fact that Chihuahuas are predisposed to tear staining, the most common cause of this condition is an overproduction of tears (known as epiphora).  Chihuahuas don't necessary cry when they upset or frightened, but they will produce tears to lubricate their eyes; protect against foreign objects; improve visual clarity; and nourish their eyes with nutrients. If a Chihuahua suffers from an infection, blocked tear duct, allergies or irritation, however, they may produce an excessive amount of tears, which leads to tear stains.

Now let's take a closer look at some of the underlying causes of tear stains in Chihuahuas...

  • Conjunctivitis. Also known as pink eye, conjunctivitis is one of the most common causes of excessive tear production and subsequent tear stains in Chihuahuas. It's characterized by inflammation of the membrane covering the eyeball and inner eyelid (the conjunctiva). In addition to watery eyes, other symptoms of conjunctivitis include eye redness, inflammation, mucus discharge, squinting, and eyelids stuck together. Conjunctivitis is caused by viral and bacterial infections, allergies, irritation, or hereditary conditions. The good news is that most cases of conjunctivitis are easily treated using antibiotics for bacterial infections; antiviral medication for viral infections; and hydrocortisone drops and anti-inflammatory medication for allergies.
  • Blocked Tear Duct. In the corner of a Chihuahua's eyes are narrow ducts through which old tears are flushed. If one or both tear ducts becomes obstructed with dust, grass particles or other debris, the Chihuahua's tears will accumulate in the socket before spilling out. If you believe your Chihuahua has a blocked tear duct, schedule an appointment with your veterinarian. Vets can diagnose blockages by placing fluorescein dye drops into the Chihuahua's eyes and then inspecting the nostrils to see if it's being properly flushed. If no blockage is present, the fluorescein dye will appear in both nostrils. If there's a blockage in the Chihuahua's right-eye tear duct, however, the dye will only appear in the left nostril, or vise-versa for blockages in the left-eye tear duct.
  • Congenital Defects. Some Chihuahuas are just born susceptible to tear stains. Imperforate lacrimal puncta is a congenital defect in which the dog is born without tear duct openings. Surgery is typically the only treatment option for this defect. Other Chihuahuas are born with narrow tear ducts, making them more prone to blockages. In these Chihuahuas, the veterinarian may recommend flushing the blocked tear duct with a saline solution.
  • Entropion. This condition is characterized by inversion of the eyelid. When a Chihuahua's eyelid rolls inward and becomes inverted, it causes fur on the eyelid to make direct contact with the eyeball, causing irritation and excess tear production. Entropion can affect either a portion of the Chihuahua's eyelid or the complete eyelid. It typically affects both eyelids and is associated with aging.
  • Allergies. Exposure to common allergens such as tree, plant and weed pollen can also cause tear stains, usually affecting both eyes. For severe allergies, a veterinarian may prescribe steroidal medication like Vanectyl-P. Steroids work by suppressing the immune system, preventing it from going into "overdrive" when it detects an allergen. As a side effect, though, Chihuahuas are more likely to get sick from infection when taking them. Antihistamines like clemastine, chlorpheniramine, and hydroxyzine are used to treat acute allergies in Chihuahuas.
  • Glaucoma. Chihuahuas suffering from glaucoma have a greater risk of developing tear stains. Glaucoma is a condition in which excess pressure builds up inside the eyeball, often causing pain, watery eyes and eventually vision loss. It's either classified as primary when it's inherited, or secondary when other diseases or conditions trigger the pressure buildup. Certain breeds such as the American Cocker Spaniel, Basset Hound, Shar Pei and Jack Russel Terrier are predisposed to glaucoma. Chihuahuas generally have a low risk of developing glaucoma.
  • Irritation. Overgrown fur around the eyes is a common problem in long-coat Chihuahuas. When the fur becomes too long, it can poke against the eyeball while triggering excess tear production. Having your Chihuahua professionally groomed on a regular basis can prevent overgrown fur and its associated problems. Both short-coat and long-coat Chihuahuas are susceptible to eye irritation from foreign objects like splinters, grass awns and stray fur.
  • Poor Diet. Your Chihuahua's diet may influence their tear stains. Feeding your Chihuahua low-quality food consisting mostly of heavily processed "filler" ingredients can cause excess porphyrin production. With more porphyrins present in their tears, your Chihuahua will develop stains more easily. Even the water your Chihuahua drinks can affect their tear stains. Unfiltered tap water often contains iron, fluoride, chlorine, lead and other impurities, so try switching over to filtered or distilled water instead.

How to Treat Tear Stains

Chihuahua tear stains

Remove tear stains with a damp cotton ball

The method for treating a Chihuahua's tear stains varies depending on its underlying cause, and as you can see there are many different causes. Something as simple as flushing the eyes can eliminate tear stains if there's a blockage. If allergies cause your Chihuahua's tear stains, antihistamines or steroids may work. For tear stains caused by conjunctivitis, antibiotics or anti-viral medication is used.

Cleaning and Drying Your Chihuahua's Tear Stains

While it's best to treat the underlying cause of tear stains, owners can provide their Chihuahuas with temporary relief by cleaning and drying the stained fur. This serves two purposes: it keeps your Chihuahua's coat looking clean, and it reduces the risk of a yeast infection.

The next time you see tear stains on your Chihuahua, soak a cotton ball in lukewarm water -- just enough so that it's damp -- and gently blot the stained fur until it comes clean. If the stain has hardened, you may need to gently scrub the area using a moistened paper towel, after which you should go back over the fur with a dry paper towel to eliminate any excess moisture.

If water alone isn't enough to clean your Chihuahua's tear stains, try using a tear stain wipe. These are single-use wipes containing special ingredients to remove stubborn stains. When choosing a tear stain wipe, read the ingredients to ensure it doesn't contain alcohol, sulfates, phosphates or other harsh chemicals. Tear stain wipes should only contain gentle, non-irritating ingredients like water, aloe vera, glycerin, coconut oil, fruit oil, etc.

Also, owners should avoid using the Angels' Eyes and Angels' Glow tear stain removal products. The Federal Drug Administration (FDA) issued a warning, saying these products were being sold illegally. According to the FDA's statement, Angels' Eyes and Angels' Glow contain the antibiotic tylosin tartrate, which has not been approved for use in dogs or cats.

What About Vinegar, Hydrogen Peroxide or Other Home Remedies?

We've heard reports of owners cleaning tear stains with everything from apple cider vinegar and hydrogen peroxide, to milk of magnesia, Visine and corn starch. Even if home remedies such as these remove stains, we do NOT recommend using them. Apple cider vinegar and hydrogen peroxide burns the eyes, and corn starch can further obstruct your Chihuahua's tear ducts. You can add a teaspoon of organic apple cider vinegar to your Chihuahua's water dish to help flush toxins from their system and balance their pH levels, but you should not apply it directly on their eyes or skin.

Ultimately, you must identify the root cause of your Chihuahua's tear stains to effectively treat this condition. Drying and cleaning the stains is only a temporary solution, so schedule an appointment with your veterinarian for a professional diagnosis.

How do you manage your Chihuahua's tear stains? Let us know in the comments section below!

References:

http://www.akc.org/content/dog-care/articles/tear-stains/

http://healthypets.mercola.com/sites/healthypets/archive/2014/11/12/pet-tear-staining.aspx

http://www.vetstreet.com/care/conjunctivitis-in-dogs-and-cats




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