My dog’s eyes are bloodshot. What does it mean?
This is the question we get asked most often. The quick answer: It means he is not 100%. There may be little you can do at home and there may be a lot that needs to be done, but no matter what: He is not 100%. What else could it mean? One of the things that vets look for when they suspect certain viral diseases (incl. canine distemper) is bloodshot eyes. My dog has this symptom and I don’t think it’s one of those diseases, so what does it mean? As always, the quick answer only deals with 95% of such cases: It means he is not 100%. Symptoms that may accompany bloodshot eyes: Loss of appetite, diarrhea, vomiting. Anything else? Not really. Bloodshot eyes are just one possible symptom of several diseases and they do not tell much about the severity of the disease or how far it has progressed or if there is any chance for recovery or not. Read on below to find out what blood-colored eyes could mean in dogs…

Top 5 reasons why your dog’s eyes are bloodshot
1 Infectious canine distemper (a viral disease)
2 Hormonal problems (disturbed thyroid gland function, Cushing syndrome)
3 Poisoning
4 Allergy (e.g., dust)
5 Internal bleeding
Read more about these topics here! Also, read about how to protect your pet from these diseases!
Why do dogs have bloodshot eyes – The answer in detail
1 Infectious canine distemper (a viral disease)
Distemper is a serious, contagious and often incurable viral infection. It usually manifests with the symptoms described above (“bloodshot eyes” being one of them). If you suspect that your canine companion might have contracted this disease, then take it to the vet immediately.
2 Hormonal problems (disturbed thyroid gland function, Cushing syndrome)
Canine hypothyroidism is one of the most common hormonal disorders in dogs all over the world. It literally means “underactive thyroid gland”. That’s why this disorder goes hand in hand with symptoms like lethargy, loss of appetite and weight in dogs. Disturbed thyroid gland function in dogs may also cause bloodshot eyes, but there are several more symptoms that your canine companion will exhibit if it has this disorder (e.g., coarse/dry/thinning hair).
Hair loss due to Cushing’s syndrome in Dachshunds
A very similar disease is called Cushing’s syndrome in humans . It is caused by the disturbance of the normal production of cortisol by the adrenal gland. The result: Hair loss – often accompanied by increased hair shedding – is one of its main symptoms. Cushing’s syndrome affects middle-aged to older pets (5 years or older) mostly, but some breeds are also prone to it (e.g., Dachshunds).
3 Poisoning
If other symptoms like diarrhea, vomiting or loss of appetite are present in addition to bloodshot eyes (and other symptoms like lack of coordination), then poisoning should not be neglected. It is one of the most common causes for these symptoms and veterinary intervention may be needed immediately.
4 Allergy (e.g., dust)
When it comes to allergies, dogs can develop them really easily even if they were brought up in the best possible environment. The only thing you need to trigger an allergic reaction is a specific allergen stimulus that your pet has never been exposed to before – even a small amount might cause a serious reaction. Depending on the allergen, symptoms like asthma and anaphylactic shock (shock due to histamine release) may occur and one of the possible symptoms is bloodshot eyes.
5 Internal bleeding
The most common cause for this symptom in dogs is gastritis . It literally means “inflammation or erosion of the stomach”. Some other diseases that might cause internal bleeding as well are: Heart disease , kidney disease , pancreatitis and liver disease . Dogs may also develop bloodshot eyes if they have a tumor somewhere else in their body which causes them to bleed internally. Also, other general symptoms like lethargy, lack of appetite and weight loss should be present before you can diagnose any of these conditions…
What other there could be?
If your dog show any of the symptoms described above, then there is definitely something wrong with it. That’s why you should call the vet right away. Sometimes dogs get bloodshot eyes when they are legitimately excited . It can also be a symptom of hypoglycemia (low blood sugar) and shock – both serious conditions that require immediate veterinary attention.
What do bloodshot eyes indicate?
As you can see, bloodshot eyes are not a serious disease on their own. However, they could indicate the presence of several otherwise serious conditions in your canine companion. That’s why it is always advisable to call the vet right away if you notice this symptom in your pet. For example, hypothyroidism might be treated with thyroid medication if it is detected in time. If you notice any of the symptoms described above, then there is definitely something wrong with your dog and bloodshot eyes are only one possible symptom of several others.

That’s why you should get in touch with a vet immediately if you ever notice this symptom in your pet.
How do I treat my dogs red eye?
There are several ways to treat bloodshot eyes in dogs. They range from treating the underlying cause of the symptom to symptomatic treatment which means that you’ll have to rely on your vet for advice. Depending on the illness, a dog might need additional procedures or tests before a veterinary prescribes a certain treatment option.
Bloodshot eyes in dogs can be the result of several different disorders and conditions. If you notice that your dog has bloodshot eyes, then you should call your vet right away to find out what’s wrong with it.
Symptoms of bloodshot eyes: inflammation, watery eye, red eye, glaucoma, inner ear infection, runny nose, bulging eyes, loss of vision.
In some instances, bloodshot eyes are a result of serious conditions that need immediate medical attention and can even cause death if not treated in time. That’s why it is important to contact your vet as soon as possible. For example, a disorder called hydrocephalus will cause increased cranial pressure which, in turn, will cause bulging eyes as a symptomatic effect. Also, it might indicate a chronic disorder called hepatic encephalopathy . In addition to this symptom, additional symptoms of this condition include: confusion and lethargy.
“What else could cause bloodshot eyes in dogs?”
Bloodshot eyes are commonly the result of a dog’s enthusiasm or pain . This is especially true in cases of gastrointestinal disorders when the stomach acid erodes the inner lining, which results in bleeding.
Should I worry about a bloodshot eye?
Bloodshot eyes in dogs can be a symptom of several different conditions and diseases. However, they are usually the result of excitement or pain . If your dog has bloodshot eyes and you notice that it is lethargic or unable to move, then this might indicate a serious disease such as hydrocephalus . In other cases, bloodshot eyes are a symptom of glaucoma, an infection in the eyes or inner ear, allergies , and eye injuries .If your dog has bloodshot eyes, then it is important to get in touch with your vet right away for advice.
How long do bloodshot eyes last?
That depends on the underlying condition. In some cases, bloodshot eyes can last for a day or two, but it might also indicate several other more serious conditions that require immediate medical attention.

In many instances, bloodshot eyes are nothing to worry about and will go away by themselves. However, if your dog is lethargic or has lost its vision, then this is definitely something to be concerned about and requires immediate veterinary attention.
How can you treat a dogs red eye?
Depending on the underlying illness or condition, there are several treatment options available for dogs with bloodshot eyes. These include: symptomatic treatment, antibiotics for infection , anti-inflammatory medication, ointments, and medications for glaucoma . In some cases, your dog might need surgery in order to remove a foreign body from its eye.
“What can I do about my dogs red eye?”
In many cases, bloodshot eyes are the result of several different conditions or diseases. However, most often they are caused by excitement or pain . If your dog has bloodshot eyes and you notice that it is lethargic or unable to move, then this might indicate a serious disease such as hydrocephalus . In other cases, bloodshot eyes are a symptom of glaucoma , an infection in the eyes or inner ear, allergies , and eye injuries .