Pigmentary Keratitis in Dogs

Does your dog have dark, stain-like areas on the surface of its eyes? If so, then you should be aware of the condition known as pigmentary keratitis. This eye disorder can cause pain and discomfort for your furry friend, making it important to recognize the signs and symptoms of this condition. Pigmentary keratitis in dogs is an inflammation of the cornea that can lead to significant vision problems if not treated promptly and appropriately. Knowing how to identify it early on will help ensure that your pet receives proper care before any permanent damage is done. In this article, we’ll provide an overview of what pigmentary keratitis in dogs looks like, its causes, treatments available, and tips for prevention.

What is pigmentary keratitis in dogs?

Pigmentary keratitis is a condition that happens when the clear front part of a dog's eye, the cornea, reacts to chronic inflammation. With time, this causes the outer layers of the cornea to change color, developing a pigmented appearance. Even though this condition can be a bit vague, it's important to understand how it develops in order to choose the right treatment for your furry friend.

Most pugs and other brachycephalic breeds are highly likely to develop keratoconjunctivitis sicca (KCS) due to their facial structure. In fact, a recent study found that 80% of pugs will develop pigmentary keratitis with time.

What are the causes of pigmentary keratitis in dogs?

Risk factors for the development of pigmentary keratitis can include a variety of conditions and situations. The following have been known to contribute to the development of pigmentary keratitis in dogs:

What are the symptoms of pigmentary keratitis in dogs?

Corneal pigmentation does not typically cause discomfort, and signs or symptoms may be absent until it impacts vision. Notably, recognizable complications in dogs with this issue are generally associated with underlying root causes rather than the pigmentation itself.

In dogs with short, flat faces (brachycephalic breeds), the pigmentation often starts in the area closest to the nose but can spread to cover the entire surface of the cornea in more severe cases.

How is pigmentary keratitis diagnosed?

Identifying pigmentary keratitis in dogs is usually straightforward through a simple examination of the cornea. The pigmentation can appear as light speckles, faint swirls, or even dense black patches that make it hard to see the inner parts of the eye. Depending on the root cause, the pigmentation might be accompanied by blood vessels growing in the cornea, scarring, or fatty deposits.

To determine the cause of pigmentary keratitis in dogs, it is important for your veterinarian to conduct tests and eliminate any underlying ocular conditions. Examples of evaluations include assessing the ophthalmic reflexes and administering the Schirmer Tear Test (STT) to rule out facial nerve paralysis and dry eye respectively.

What are the treatment options for pigmentary keratitis?

The identification and mitigation of underlying causes are crucial components of successful treatment. Therefore, an accurate diagnosis of the root cause(s) is necessary to establish an appropriate treatment plan.

The objective of treatment is to cease the progression of pigmentary keratitis. Full pigment regression is uncommon. Some cases of KCS (dry-eye) may have an exception where corneal transparency may improve notably with increased tear production following the medical therapy. The outcome varies and depends on the root cause and the ability to correct or eliminate it.

Medical treatment for pigmentary keratitis in dogs usually involves the use of eye medications, such as:

1. Ocular lubricants: Frequently applying thick eye lubricants to your dog can help to protect its cornea from exposure to or irritation by harmful elements.
2. Cyclosporine and tacrolimus: These medications are believed to help reduce pigmentation, although the exact way they work is still unclear. They can be applied topically (directly on the eye) once or twice a day.
3. Topical steroids: While some people have reported success using steroids combined with cyclosporine or tacrolimus, it's important to note that long-term use of steroids may increase the risk of corneal ulcers, infections, and hazing of the cornea with chronic use.

In conclusion, to ensure the good eye health of their dogs, it is important for owners to know the signs and symptoms of pigmentary keratitis. Regular veterinarian check-ups and proper eye care can help identify and address any underlying issues that may contribute to this condition. Monitoring your dog for any changes in their eyes is crucial in providing them with the best care possible. If you notice any unusual symptoms or suspect your dog may be experiencing discomfort, don't hesitate to consult your veterinarian for professional advice and guidance. By working closely with your veterinary team, you can work together to find the best treatment options for your dog.