Eye Cancer Symptoms in Dogs

It's hard to keep up with all of the health concerns that come with dog ownership, but you vigilantly make sure your dog gets her vaccinations, receives her heartworm treatment on time, and maintains a healthy weight. But did you know that your dog's eyes might indicate a potential health issue? Eye cancer in dogs can occur, so the next time you look your dog in the eye, be sure to check for anything that seems abnormal.

Checking the eyes
Eye Cancer Symptoms in Dogs
credit: razyph/iStock/GettyImages

Uveal melanomas

Uveal melanomas are usually found toward the front of the eye, often positioned toward the front of the iris' surface, states Pet MD. They look like a visible pigmented mass and can cause an irregular appearance of the pupil. You may notice that your dog has an inflamed eye, and this dog eye melanoma can cause glaucoma, which refers to increased pressure in the eye. In some cases, your dog may develop blood in her eye.

Uveal melanomas generally don't cause a dog to lose his vision, unless they grow in a way to obstruct the pupil. While these tumors are usually benign, they can still quickly destroy a dog's eye if they're left untreated. The tumors have a 4 percent rate of cancerous spreading through a dog's bloodstream, where they can then affect the dog's other organs.

Choroidal melanomas

While uveal melanomas are often easy to spot, choroidal melanomas often go undiagnosed because of their location. These dog eye melanomas grow much farther back in the eye, according to Pet MD. They are quite rare, and they rarely metastasize. Because these tumors are so slow-growing, the affected eye rarely needs to be removed.

Eyelid tumors

If you notice a tumor under a dog's eye, you may be dealing with an eyelid tumor. The Pet Cancer Center states that eyelid tumors are identified by a growing mass on the dog's eyelid. They are also sometimes accompanied by eye discharge or conjunctivitis.

There are many types of eyelid tumors, including meibomian gland adenomas, papillomas, squamous cell carcinoma, mast cell tumors, and basal cell tumors. Tumors can be benign or malignant, so it's important to determine the type of tumor you're dealing with. This is done via a biopsy that is then sent away for analysis. Malignant tumors may require additional diagnostic testing, including MRIs and X-rays.

Diagnosing eye cancer in dogs

Diagnosing eye cancer in dogs can be a complicated process. According to Pet MD, your vet will begin by performing a complete eye exam on your dog, during which they'll test the pressure in your dog's eye. Your vet will likely also order a complete blood profile, a complete blood count, and an electrolyte panel to look for increased white blood cells indicating your dog's body is fighting the growth.

Additionally, your vet may want to order some X-rays, and possibly perform an ultrasound to determine if the tumor is malignant and how large it is.

Treating eye cancer

While choroidal melanomas can often be allowed to go untreated, uveal melanomas do require more attentive treatment. Pet MD states that depending on the tumor's size and location, you may be able to monitor it for three to six months.

Ultimately, most uveal melanomas need to be removed. Most vets will perform an enucleation, a procedure in which your dog's affected eye is removed. This eye removal is performed for many reasons, but some of the most common are when the tumor grows quickly, the eye can't be saved, the tumor is impeding the eye's sight, and the tumor is causing additional issues such as bleeding.

According to the Pet Cancer Center, eyelid tumors are often surgically removed. Depending on the size, location, and malignancy of a tumor, chemotherapy or radiation may help to reduce the tumor's size. In most cases, though, surgery is the preferred option, and some reconstructive work may be needed to rebuild your dog's eyelid.