TL;DR: A bright red spot on the white of your dog’s eye is typically a painless surface bruise called a subconjunctival hemorrhage, but you should see a vet within 24 hours to rule out serious underlying health issues.
What does it mean if my dog has blood in the white of their eye?
Finding a bright red patch on the white part of your dog's eye (the sclera) can be alarming. This condition is typically known as a subconjunctival hemorrhage. It occurs when a tiny blood vessel beneath the clear surface of the eye (the conjunctiva) breaks and leaks. While it looks dramatic and frightening, it is essentially a bruise on the surface of the eye.
Is blood in my dog's eye a veterinary emergency?
- The urgency level for blood in the white of the eye is generally considered Medium.
- While the red spot itself is often harmless and painless, it can sometimes be a symptom of a more serious underlying health issue such as trauma, high blood pressure, or a blood clotting disorder.
- You should schedule a veterinary appointment within 24 hours to ensure there is no internal damage or systemic illness causing the bleed.
How does taking a photo help the veterinary triage team?
- A clear, well-lit photo allows the professional to distinguish between a surface bruise and blood inside the eye (hyphema), which is a much more serious emergency.
- It provides a baseline to see if the redness is spreading or receding during follow-up checks.
- Visuals help the triage team determine the urgency of your dog's specific condition more accurately.
Clinical Context (Merck Veterinary Manual)
Subconjunctival hemorrhage (blood in the white of the eye) in dogs can arise from trauma, blood dyscrasias, von Willebrand factor deficiency, and certain infectious diseases. If there is no history or evidence of trauma, a systemic examination is indicated to determine the underlying cause of the spontaneous hemorrhage. In cases of traumatic retrobulbar hemorrhage, orbital and ocular contusion can damage the orbital vasculature and cause exophthalmos, iridocyclitis, and lagophthalmos; subconjunctival and intraocular hemorrhage may also be present, potentially preventing intraocular examination. Corneal and scleral lacerations should be excluded, and B-scan ultrasonography is recommended to detect retinal detachment in eyes with intraocular hemorrhage.
Chapter: Ophthalmology, Dermatology, Emergency, Infectious Disease
Source: The Merck Veterinary Manual, 11th Edition (Page 492)