While the brown tear stains on your dog’s face are usually caused by excess tear production (called epiphora), there are many reasons why your dog might have them.
Some reasons for excess tear production are congenital, while others are related to environmental factors like diet, irritants, or allergens. Some, however, indicate underlying health conditions — so always consult your vet to rule these out.
Here are seven tear stain causes and what you can do to get rid of them.
1. Diet
Low-quality dog food usually contains poor-quality ingredients such as food additives, non-nutritive fillers, animal digest, and animal by-products — all of which can be highly allergenic and place undue stress on your dog’s body. Allergic reactions to the ingredients in these foods can also cause your dog’s eyes to water excessively — resulting in tear stains.
Check your dog’s food label and avoid common filler ingredients like wheat and other known allergens. In high-quality dog food, the first ingredient in the ingredients list should always be a named meat source (chicken, pork, beef, turkey, fish, etc.)
2. Conjunctivitis
If your mature dog suddenly develops tear stains, one of the most common causes is conjunctivitis. Conjunctivitis is inflammation of the eye lining, accompanied by discharge.
An injury can cause conjunctivitis to the eye or an allergy. In the summer, conjunctivitis is often caused by an irritation in the eye — such as pollen or a grass seed — which results in excess scratching, making the irritation worse.
Eye infections are also caused by viruses, bacteria, parasites, irritants like dust and smoke, and even dog shampoo ingredients.
Try to reduce your dog’s exposure to allergens (if possible). Your vet will prescribe eye drops that contain anti-inflammatory agents, antihistamines, or antibiotics.
3. Ear infection
Ear infections are common, and they can cause one or both of your dogs’ eyes to water more than usual.
If only one of your dog’s eyes has tear stains, your vet will usually check for an infection in the ear on the same side. Then, the vet will clean the ear thoroughly with a medicated ear cleanser. If the infection is severe, your vet may prescribe antibiotics and ear drops for you to administer at home.
4. Allergies
Allergens in your dog’s food, the environment, or even the cleaning products you use in your home can cause dog tear stains.
Another symptom of allergies is itchy skin — this is called allergic dermatitis. Often, dogs with allergies will chew their paws and scratch their muzzle excessively.
Try an elimination diet, or limit your dog to only one source of protein to see if his tear stains improve. Your vet may perform a RAST test (radioallergosorbent test) to find out what your dog is allergic to, prescribe antihistamines, and recommend a change in diet.
5. Glaucoma
Your dog’s tear stains may be caused by glaucoma, which is congenital. Glaucoma causes a build-up of pressure and fluids behind the eye, which damages the optic nerve. Glaucoma is more common among older dogs, and certain breeds like the Chow, Shar-Pei, Jack Russel, Husky, and Shih-Tzu are more prone to developing the condition.
To get rid of your dog’s tear stains, you need to treat your dog’s glaucoma. Your vet may prescribe medication to reduce the pressure and discomfort in your dog’s eyes or perform surgery to correct them.
6. Brachycephalic Syndrome
Certain breeds are more prone to tear stains due to multiple hereditary conditions involving their eyes — such as entropion, poor tear drainage, shallow eye sockets, and tear deficiency.
These conditions occur in brachycephalic (short-nosed) breeds such as the Boxer, Pekingnese, Pug, French Bulldog, and Lhasa Apso.
These breeds tend to have round, bulging eyes, which can make fully closing them difficult. The surface of their eyes is irritated or damaged because their eyelids don’t completely close.
Entropion is when the dog’s eyelids fold inward, resulting in irritation from the eyelashes making direct contact with the eyes.
Your vet will be able to prescribe eye drops for tear deficiency and to soothe irritation — however, entropion and poor tear drainage may require corrective surgery.
7. Ingrown eyelashes
Ingrown eyelashes can cause immense irritation, which leads to watering eyes and tear stains. This is often a hereditary problem in Cocker Spaniels, Pekingese, Dachshunds, and poodles.
In breeds that require clipping, take care not to cut the hair too short around the face. If you do, new hair growth may point inwards and cause eye irritation. Cairn Terriers and White Terriers are particularly prone to this condition.