8 Potential Causes of Bloodshot Eyes in Dogs
Bloodshot eyes in dogs may or may not be cause for concern. There are numerous reasons why your dog’s eyes are red. For example, some naturally have red in their eyes.4
In this article, we'll cover the following topics regarding bloodshot eyes in dogs:
- Common causes and their symptoms
- Potential treatment options
- When to see a veterinarian
1. Corneal Ulceration
Corneal ulcers happen if your dog gets a scratch on their eye or a foreign object stuck in it. As a result, the cornea can appear red.1
Symptoms
- Squinting with one or both eyes
- Discharge from the tear glands in the inner corner of the eyes
- Scratching or rubbing at the eyes
- Excessive blinking
Treatment
To treat a corneal ulcer, your vet might prescribe antibiotic eye drops to prevent infections from developing in your dog’s eye.
2. Eye Trauma
Eye injuries are common in dogs, especially if they get a foreign body stuck in their eye while playing. For example, if your dog fights with another dog or animal, that leads to an eye scratch or injury, it might appear red.
Symptoms
- Bleeding
- Discharge
- Watery eyes
- Bacterial infection from wounds
- Squinting
- Swelling
- Sensitivity to bright light
Treatment
The best treatment for an eye injury depends on the type. Your dog will need a proper diagnosis from a veterinary ophthalmologist.
In severe cases of physical trauma, your dog might need surgical treatment or stitches. The vet may prescribe pain medications.
3. Conjunctivitis
Conjunctivitis (pink eye) can occur in people and dogs. A viral or bacterial infection causes this condition and leads to your dog’s eyes reddening.2,3,8
Symptoms
- Itchiness
- Swelling
- Watery discharge
- Excessive blinking or squinting
Treatment
You can usually treat conjunctivitis with eye drops. They can also treat other symptoms of pink eye beyond eye redness. For example, they help lubricate your dog’s eyes and prevent pain and itchiness.
4. Environmental Irritants & Allergies
Certain environmental irritants can affect your dog’s eyes. These include dust or other allergens in the air.2 They can also have a food allergy that can cause red eyes.
Symptoms
- Itchy eyes
- Scratching or rubbing at the eyes
- Watery eyes
- Dry eye
- Inflammation
- Swelling
Treatment
If seasonal allergies are causing your dog to have bloodshot eyes, ointments or oral medications might help. In the case of seasonal allergies, bloodshot eyes and other symptoms typically subside on their own. Allergy testing, such as blood tests, can help determine or rule out specific food and pet care product allergies.
5. Infection
Redness is a common symptom if your dog’s eye has an infection. If left untreated, the condition and symptoms can worsen and become painful.
Symptoms
- Enlarged blood vessels
- Watery discharge
- Itchiness
- Pain
Treatment
If your dog has an eye infection, the vet may prescribe an ointment or medication to kill the bacteria causing the infection.
6. Eyelid Problems
Eyelid problems can also cause red eyes in dogs. It can happen if the eyelids fold out (ectropion) or in (entropion). When they fold out, your dog’s eyes are left unprotected. When they fold in, the eyelashes can irritate the eye's surface.
Symptoms
- Folded eyelids
- Itching
- Dry eye
Treatment
Many long-haired and flat-faced breeds have trouble with their eyelids due to fur and skin obstructing their vision. Keeping your dog’s eyes healthy by maintaining proper pet care is important.5,7
7. Glaucoma
Glaucoma is a common condition that affects many older dogs. It can lead to red eyes and other symptoms.6 It occurs due to a fluid build-up in the eye, which causes pressure.
Glaucoma is a serious eye condition that can lead to vision loss. Because of this, it's important to see a veterinarian immediately.
Symptoms
- Difficulty seeing
- Cloudy eyes
- Dry eyes
- Eye swelling
- Abnormal discharge
- Haziness in the eye
- Pain
Treatment
Glaucoma in dogs can get worse with age. Oral or injected medications can help treat glaucoma. In some cases, your dog may need surgery.
8. Dry Eye Syndrome
Dry eye syndrome or keratoconjunctivitis sicca (KCS) is a health condition that can affect people and dogs. It happens when the eyes do not produce enough moisture and feel very dry, causing redness.2
Some breeds of dogs are more prone to dry eye syndrome than others. It's typically caused by an injury or a weakened immune system, which can lead to infection or corneal ulcers.
Symptoms
- Dry eyes
- Difficulty seeing
- Eye redness
- Inflammation
- Mucus or eye gunk
Treatment
If your dog suffers from dry eye syndrome, your vet might prescribe artificial tears to help induce tear production and lubricate their eyes. They may also prescribe antibiotic eye drops or immunosuppressant drugs, depending on the cause.
When to See a Veterinarian
Typically, you can treat your dog's red eyes with medications. However, you should talk to your veterinarian if your dog’s red appears out of nowhere or gets worse over time. Especially if your dog's eyes don't improve with treatment.
Other signs that you should call a veterinarian include:
- Noticing something new or odd in your dog's eye
- Frequent eye scratching or rubbing
- Eye swelling
- Eye discharge or gunk
- Excessive squinting
How Do You Prevent Bloodshot Eyes on Your Dog?
There are various ways to prevent red eyes and keep your dog's eyes as healthy as possible. Here are a few things you can do to prevent red eyes on your dog:
- Grooming and hair trimming around the eyes
- Cleaning eye discharge or gunk
- Keep an eye out for excessive eye rubbing or scratching
- Regular veterinary exams
Summary
The recovery timeline depends on why your dog’s eyes are red. The outlook is generally positive since most cases resolve independently or with eye drops.
However, if a more severe condition like glaucoma is the cause, your dog might require lifelong treatment. If you’re concerned, talk to your veterinarian so they can determine a proper treatment plan for your dog.
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