Retinal Hemorrhage in Dogs
The retina, positioned as the innermost layer of the eye, lies directly beneath the middle choroid coat. This coat is situated between the retina and the sclera, which forms the outer white lining of the eye. Within the choroid coat are connective tissues and blood vessels responsible for supplying nutrients and oxygen to the outer layers of the retina. In some instances, the retina may detach from this layer, a condition known as retinal detachment. Retinal hemorrhage, on the other hand, refers to a situation where there is bleeding into the innermost lining of the eye, either in a localized or generalized area. The causes of retinal hemorrhage typically stem from genetic factors and are specific to certain breeds.
Symptoms and Types
- Vision loss or blindness, leading to instances of bumping into objects
- Bleeding observed in other body parts, manifesting as small bruises scattered throughout the body
- Presence of blood in urine or feces
- Whitish appearance of the pupil
- Pupil may fail to contract in response to bright light being shone into the eyes
- Occasionally, no observable signs may be present
Causes
Genetic (present from birth):
- Flawed development of the retina or the lubricating fluids of the eyes (vitreous humor)
- Certain breeds are more susceptible, including Shetland Sheep Dogs, Collies, Labrador Retrievers, Australian Shepherds, Sealyham Terriers, Bedlington Terriers, English Springer Spaniels, and Miniature Schnauzers.
Acquired (develops sometime after birth):
- Trauma or injury
- High blood pressure (hypertension) affecting the entire system
- Conditions like kidney disease and heart disease
- Elevated levels of thyroid hormones
- Increased levels of certain steroids
- Exposure to specific chemicals such as paracetamol
- Certain fungal and bacterial infections
- Various forms of cancer
- Blood disorders such as blood-clotting disorders, anemia, and hyperviscosity of blood
- Diabetes
- Inflammation of blood vessels
Diagnosis
Your veterinarian will conduct a comprehensive physical examination of your dog. It’s important to provide your veterinarian with a detailed history of your dog’s health, including when symptoms began and any potential incidents that could be related to the condition. Standard laboratory tests will be conducted, including a blood chemical profile, complete blood count, electrolyte panel, blood pressure test, and urinalysis, to rule out other underlying causes of the disease.
The physical examination will include a thorough ophthalmic examination using a slit lamp microscope. This examination will closely assess the retina at the back of the eye for any abnormalities. The electrical activity of the retina will also be evaluated. In cases where hemorrhaging obstructs visualization of the retina, an ultrasound of the eye may be performed. Samples of vitreous humor (eye fluid) may be collected for laboratory analysis. If your dog belongs to a breed prone to familial retinal disease, genetic testing may also be recommended.
Treatment
Dogs with retinal hemorrhage typically require hospitalization and specialized care under the supervision of a veterinary ophthalmologist. Treatment will involve medication tailored to address the underlying cause of the disease. In certain cases, surgical intervention may be necessary to reattach the retina to the choroid coat.
Living and Management
Your veterinarian will arrange regular follow-up appointments to monitor the progression or improvement (particularly after surgery) of the retina and the underlying disease responsible for its detachment. These visits will include repeat blood tests and ophthalmic examinations. If your dog does experience blindness due to retinal detachment, it’s important to note that once the underlying disease is managed, the eye will no longer cause pain to your dog.
Although vision loss may not be reversible, your dog can still enjoy a happy and fulfilling life indoors by adapting to its other senses and familiarizing itself with the home environment. Since your blind dog will be more vulnerable, you’ll need to take extra precautions to safeguard it from potential dangers, especially around other pets and energetic children. It’s crucial to never allow your blind dog outside unsupervised and to keep a watchful eye on it whenever outdoors.