Eye Inflammation (Choroid and Retina) in Dogs

The choroid and retina are very close together within the eye, and often they both become inflamed. Chorioretinitis occurs when the condition of the choroid becomes very exacerbated and the inflammation spreads to the retina, oftentimes leading to a detached retina. This occurs when the retina becomes separated from the layer underneath it, the choroid. The retina is a very thin membrane that lies within the inner eye. This is where the images are converted into signals that are sent to the brain and tell dogs (and humans) what it is they are looking at. The choroid is underneath the retina and this layer contains many blood vessels. When one becomes damaged, both are adversely affected, and can cause loss of vision if not treated effectively. Chorioretinitis may be a result of an infection or disease that affects the body as a whole. The dog may have other disorders that tend to be found with this inflammation such as distemper, toxoplasmosis, fungal infections, tuberculosis, and toxic infections caused by microorganisms. 

Eye Inflammation of the choroid and retina in dogs is an eye disorder that affects the choroid and retina simultaneously. The retina can detach from the layer under it, the choroid, and cause eye and vision abnormalities.

Symptoms of chorioretinitis are hard to ignore, as the dog’s eyes will show irritation and discomfort. Symptoms include:

• Watery discharge from eyes
• Pawing at the eyes
• General discomfort
• Discolored retina (as seen in examination)
• Spots or greying of the retina (as seen in examination)

Types

Chorioretinitis does have several types differential diagnoses. These eye disorders may be very similar to chorioretinitis. Types of similar eye disorders that the veterinarian must rule out via complete testing are:

• Hypertension-caused retinal detachment
• Retinal degenerations (hereditary)
• Multi-focal retinal dysplasia

The causes of chorioretinitis can be anywhere from an internal disorder causing the inflammation to an outside source, such as a parasite that has entered the body of the dog. Causes can include:

• High blood pressure (hypertension)
• Polycythemia Vera (bone marrow abnormality)
• Parasites, such as Brucella, Toxoplasmosis, Toxocara canis, Curterebra, and Trypanosoma 
• Fungal infections, such as Coccidioides, Cryptococcus neoformans, and Acremonium
• Trauma and hemorrhage
• Distemper

If you think your dog is having difficulty with vision, a veterinarian visit needs to be planned. Your veterinarian will do a complete examination and ask questions about his symptoms, when they began, and about other illnesses or symptoms that appear unrelated to the eye disorder. The veterinarian will take the dog’s blood pressure, perform a retina screening using an ophthalmoscopy, which allows the medical professional to see inside the eye by the use of bright light. 

He may also perform testing on the fluid in the eye by taking a sample and looking at it more closely. The veterinarian may also choose to do a spinal tap to check for any infection that your dog may have that is related to his disorder.  A spinal tap is performed by taking a needle and collecting fluid from the spinal vertebrae. He will be looking for an abnormality in the central nervous system or within the optic nerve.

Chorioretinitis can be treated, although success rates of the treatment do vary. This inflammation usually takes time to become noticeable and to accurately diagnose, and in these later stages, successful treatment is questionable. In many of the cases, the inflammation is diagnosed only when signs of blindness have occurred. Treatment methods include:

Steroids

Steroid medications have been shown to have good results on dogs that have been diagnosed with the early stages of chorioretinitis.

Enzymes

Therapeutic enzyme treatment has also been used to help this condition, but is only effective in the early stages of this inflammation.

In terms of recovery, if your dog has severe chorioretinitis, prognosis is poor in terms of vision. Ultimately this can lead to blindness, glaucoma, and cataracts. To prevent this, getting routine eye examinations for your companion can help it become diagnosed in the early stages before damage occurs. 

Your dog may still live a full life if he is cared for very well while having blindness or other eye diseases. Concerns can be discussed with your veterinarian in terms of decisions that need to be made for your dog to be happy and have a fulfilled life. Your veterinarian can give you advice on how to care for a dog with severe eye conditions brought on by chorioretinitis.