the hairy eyeball: ocular dermoids in pets
While covering a shift at the clinic the other day, I had a very interesting phone call and follow up exam. One of our clients, who has a soft spot in her heart for Dachshunds, had adopted a young puppy. The puppy was doing great at home, but the pet parent was concerned about the hair in the puppy’s eye. After speaking with her for a bit, I came to realize that she was describing hair growing on the eye itself. Unable to make a diagnosis over the telephone, I encouraged her to bring the puppy in to the office. Upon examination, I discovered that her newly adopted puppy had an ocular dermoid (also referred to as a choristoma). I decided then and there that this would be the perfect topic for my next blog.
So, what is an ocular dermoid? For starters, a dermoid is a skin-like growth that develops in an abnormal location. In other words, this is normal tissue (i.e.: this is not cancer) that decides to grow in a place it doesn’t belong. An ocular dermoid is a growth of skin-like tissue on the structures of the eye. They are most commonly seen on the cornea (outer layer of the eye), eyelid conjunctiva, or third eyelid. This tissue has many of the structures of normal skin: hair, glands, fat and sometimes pigmentation. This is a congenital condition, which means it is present from birth, however, it may not be obvious until a pet gets a little older. Luckily, some pet insurance providers, like Petplan, offer coverage for hereditary conditions like this.
The most commonly affected breeds include Dachshunds, Dalmatians, Doberman pinschers, German shepherds, and Saint Bernard’s. Cats can also have ocular dermoids. They can occur in only one eye, or they can be seen in both eyes. It isn’t uncommon for there to be other abnormalities within the eye when ocular dermoids are found, so make sure your vet or veterinary ophthalmologist does a thorough ocular exam.
Owners may not even notice that their pets have an ocular dermoid, and some pets will go their whole lives without the dermoid being a problem. Other pets will experience ocular pain (usually seen as squinting or rubbing at the eye), excessive tearing, redness, corneal irritation, abnormal discharge, swelling of the tissues of the eyes, decreased vision and corneal ulcers.
The only way to definitively diagnose (and treat) an ocular dermoid is to have it surgically removed and sent off for histopathology. If your pet is experiencing any side effects from the presence of the dermoid, surgery is likely warranted. If your pet isn’t experiencing any side effects, and your veterinarian has reason to believe that it is an ocular dermoid, surgery may not be indicated. As I said before, some animals go their entire lives with ocular dermoids and never have a problem.
Fortunately, this is not a condition that needs to raise anyone’s blood pressure, or keep you up at night with worry. After discussing the condition with my client, she decided to wait and see if her new puppy exhibits any clinical signs associated with his ocular dermoid. Until then, her family just sees it as one more reason to love their very unique new puppy!