Anterior uveitis is a condition of the eye where the front chamber — including the colored iris and the muscles supporting the lens — becomes inflamed.
The word “anterior” refers to the front chamber of the eye, while “uveitis” refers to the uvea, which is made up of a ring of muscle that acts on the lens to change its shape and the fine ligaments attaching the lens to these muscles.
Inflammation can be caused by any number of reasons, from a knock or a blow to infection. As with any eye condition, if something seems off, get your pet checked by a veterinarian.
The most obvious symptom of anterior uveitis in a dog or cat is that the eye doesn’t look like the opposite eye. Any condition that involves inflammation means an increased blood supply to the tissue, and in anterior uveitis, you can see this as a red, angry-looking eye.
Sometimes the redness is on the surface or the white of the eye — or it may be within the eye when you look at the iris, the colored collar of tissue surrounding the pupil.
Indeed, if the iris is inflamed, it can look red (if it was a pale color to start with), or it can darken in color. Sometimes the iris is so sore it cannot change size, and one pupil’s size is different from the other.
The front chamber of the eye sometimes looks cloudy or hazy — blood may be present as a result of inflammation.
Anterior uveitis can result from either trauma to the eye or disease within the body causing inflammation. Of those cases of uveitis I see, by far the most common are those caused by the former.
A typical case is a dog running through the woods when a low branch hits his eye. The same is true for cats, although more typically, they get a scratch to the eye when fighting. These cases are otherwise healthy, but have a sore, painful eye.
The other side of the coin is ill animals, where inflammation in the eye is just one of many symptoms.
Diseases in dogs that can cause anterior uveitis include:
- Bacterial infections (pyometra, a tooth root infection, etc.)
- More serious illnesses such as leptospirosis or bartonella
Diseases with the symptom of anterior uveitis in cats include:
A veterinarian will make a diagnosis when she carefully examines your pet’s eye with an ophthalmoscope.
Some of the signs, such as material in the front chamber, can be subtle and only be seen with magnification in dim lighting. It is also useful to check the pressure within the eye, which can be reduced if the animal has anterior uveitis.
The animal must be screened for other causes of red eye, such as glaucoma. If the animal is not well, investigation should focus on blood tests and imaging to get to the bottom of the illness.
Treatment of uveitis as a result of trauma aims at reducing inflammation with steroid drops. Sometimes it is necessary to add drops that dilate the pupil, which relieves painful spasms in the iris as a result of inflammation.
If the condition is a symptom of a more general illness, then the key is identifying and treating that underlying condition.
Accidents do happen — it is impossible to stop a healthy, inquisitive dog or cat from getting into a scrape from time to time and knocking his eye.
Always discuss vaccination against preventable diseases such as leptospirosis (dog) and FeLV (cat) with your veterinarian to see if it is appropriate for your pet.
- Small Animal Ophthalmology. Pfeiffer & Petersen-Jones. Publisher: WB Saunders. 3rd edition.
- Manual of Small Animal Ophthalmology. Crispin. Publisher: BSAVA Publications.
This pet health content was written by a veterinarian, Dr. Pippa Elliott, BVMS, MRCVS. It was last reviewed Oct. 15, 2015.