Ocular Neoplasia in Dogs

Clinical signs can vary depending on the amount of diseased tissue present. The tissue change in your dog’s eye can grow into a tumor and you may notice it affecting your dog’s eyesight. These growths can affect different parts of the eye and can result in the spreading of the tumor to other sites on your pet’s body (known as secondary neoplasia). There are many types of growths – some can be both malignant and benign. These growths can comprise of abrasive growth on the eyelid, orbit, or other parts of the eye. Watch for any changes to the eyes of your pet and take them to your veterinarian if you see something suspicious.

Ocular Neoplasia in dogs can best be described as a tumor growth in your dog’s eye. This growth effects the tissue, and lesions can be found in the eye area.

The symptoms are not noticeable until later in development with the tumor growth but you may notice the following changes. 

• Movement – you may notice that your dog’s eyes do not move together but seem to operate separately
• Change to the pigment in your dog’s eye
• May cause eyelid swelling 
• Bulging of the eye
• Your pet may rub his eye 
• Your dog’s eye may weep or run with fluids 
• Usually painless 
• Conjunctival 

Types 

• Orbital neoplasia occurs in the tissue of the cavity, where the eye is contained
• Uveal canine lymphoma which has been spread from another area of your dog’s body
• Epibulbar melanoma which is a mass growth on the eye and often seen in German Shepherds
• Orbital adenocarcinoma which can spread from the nasal cavity in your dog 
• Ciliary body neoplasia is seen as a reddish mass on the pupil of the eye 
• Squamous cell carcinoma which affects the eyelid 

This is only a small list of possible cancers but any changes in your dog’s eyes should be noted and acted upon.

The cause of this cancer are hard to define and is a subject of ongoing research. The following list may contribute to the reason that your dog has developed this condition. 

• Persistent inflammation to the eye or socket may contribute 
• The general health of your dog may have contributed, especially if they have another metastatic cancer in their body
• Viral infection may be a cause 
• If your dog is an outside dog or goes out often, it may be UV light exposure that triggers the cancer

On arrival at the veterinary clinic, your caregiver will examine your dog’s eye and will give a full examination just to check the overall health of your friend. If the growth is easily accessible your veterinarian will take a small sample of tissue for testing in the laboratory. For a tumor that is growing inside the eye, he will need to use an ophthalmoscope that enables him to look deep into the eye (after the eye is dilated from drops).

If the tumor is growing behind the eye there is a very delicate tool known as a fine-needle aspirate that will allow him to take a minute sample of the growth for study (biopsy) which will determine if tissues have been affected. Your veterinarian may also suggest a CT scan can to see bone involvement or MRI (which will check for soft tissue damage), and blood tests. Checking for secondary complications will include looking for signs of blindness.

Depending on the type of growth, the treatment varies considerably. Superficial tumors or external growths removed by excision can allow for full recovery. Careful removal of the mass without damaging the delicate eye can produce excellent results. But where the tumor consumes the whole eye, removal of the eye is necessary. If this is the case for your dog, rest assured that he will adapt well and heal completely.

In cases where the tumor grows behind the eye, it is a bit more difficult and can cause a problem. Because these tumors tend to grow quickly, the eye must be removed, and further treatment will be required to make sure there is no further damaged tissue left. With new techniques being developed all the time, your veterinarian will advise what is best for your dog.

Where the growth has been surgically removed from the external part of the eye, recovery at home should be uncomplicated and relatively quick. Your dog will need rest. Fresh eye drops will keep him healthy and assist recovery. If your dog had an eye removed then recovery will take longer, and you may have to put ointment on the area to keep it clean and to avoid infection.

It may take your dog a little while to adapt to having just one eye, but your dog has an amazing ability to adjust and get on with living. If the tumor is malignant and the veterinarian finds it impossible to remove all of the infected area, then palliative care would be the kindest option for your friend to give good quality for the remainder of their life. Fortunately,  treatment for tumors in the eye are usually positive.