Dog Anterior Uvea Tumor
Dog Anterior Uvea Tumors
The uvea is the part of the eye that is directly behind the cornea. The iris, ciliary body and the choroid, which lies in the back of the eye, provides nutrition to the retina. The iris and ciliary body are anterior uvea and the choroid is the posterior uvea.
Tumors that are in the anterior uvea will involve the ciliary body, the iris or both. They can be primary tumors, those that originate in the eye or secondary, which have metastasized from other parts of the body.
The most common type of primary tumor of the uvea is melanoma. In dogs they usually will appear as dark brown nodules within the ciliary body or the iris. It can take several months to years to develop and form a mass. In dogs, it can also be benign and limited to the iris and slowly enlarge.
Melanomas of the ciliary body can be benign. They may enlarge and damage surrounding tissues. Others of the iris or ciliary body are malignant and can metastasize to the tissues around the eye, and to other organs.
There are three other types of tumors: Benign tumor of the ciliary body which can become malignant. The original tumor is an adenoma and the malignant becomes an adenocarcinoma. There are also tumors tha will arise from the embryonic tissues of the eye called medulloepithelioma.
The most common secondary tumors are lymphosarcomas.
If allowed to advance, the animal will have pain and eventual blindness, bleeding in the eye and glaucoma as well as damage to surrounding structures.
Signs and Symptoms
1. Color change in part of the iris
2. Observance of a nodule or mass behind the pupil or in the iris
3. Discoloration of the white of the eye
4. A change in the shape of the pupil or continuous enlargement of the pupil
5. Bleeding visible in the eye
6. Sensitivity to light, signs of pain, increased tears
7. The eye may look reddened or bloodshot
8. Potential for swelling or a visual change in the shape of the eye
Your veterinarian will want a complete history of the occurrence. A physical exam will also be done. As part of the physical, the pupil of the eye will be examined for reaction to light. To rule-out glaucoma, the pressure of the eye will be checked. It is possible that your family veterinarian will refer your dog to a veterinary ophthalmologist.
Tests such as ultrasound of the eye, blood tests and bone marrow cytology may also be done. X-rays may be done to rule out metastasis to other organs. CT scans and MRI can also be beneficial.
Dog Cancer Chemotherapy may be used for the treatment of lymphosarcoma with the fact that it is seldom successful foremost in the mind of the vet and the owner.
Most uveal tumors are treated by enucleation, removal of the eye. If the tumor is small and benign, the mass may be removed.
Additional Dog Cancer Pages
Dog Cancer | Dog Skin Cancer | Dog Bladder Cancer | Dog Pancreatic Cancer | Dog Bone Cancer | Dog Cancer Prevention | Dog Cancer Diagnosis | Dog Lymphoma Cancer | Dog Gastric Cancer | Dog Mast Cell Tumors