Esophageal cancer is rare in dogs, but it spreads quickly and can be difficult to treat. Often, cancer spreads to the esophagus from another part of the body, such as the mammary gland. When cancer originates in the esophagus, it may be the result of parasitic infection. Read on to learn more about cancer of the esophagus in dogs.
Types of Canine Esophageal Cancer
Esophageal cancer usually strikes geriatric animals. Only 0.5% of canine cancers occur in the esophagus. Dogs of all breeds and both genders can get this type of cancer.
There are three types of tumor that most commonly occur in esophageal cancer. These are squamous cell carcinoma, leiomyosarcoma and sarcomas.
Sarcomas are the most common type of esophageal tumor in dogs. Sarcomas may either be osteosarcomas, which affect the bone, or fibrosarcomas, which affect the connective tissue. Sarcomas are usually caused by an infection with the parasitic worm Spirocerca lupi. These worms occupy the walls of the esophagus and gastric tract, and can also infect the walls of the aorta.
Tumors of the thyroid, mammary glands and lymph glands are also known to spread to the esophagus.
Symptoms of Cancer in the Canine Esophagus
Dogs with esophageal cancer may have trouble swallowing. They may seem to be vomiting up undigested food, since tumors can block the esophagus and prevent food from reaching the stomach. Weight loss and lowered appetite can occur. Your dog's breath may smell terrible and he may drool excessively.
Tumors that block the esophagus can increase your dog's risk of inhaling particles of food. He may cough and could even develop a lung infection.
The symptoms of esophageal cancer are very similar to the symptoms of megaesophagus, a more common condition that occurs when the esophagus becomes distended or otherwise fails to function properly. A number of factors can contribute to megaesophagus. Your vet will need to rule out this condition before diagnosing esophageal cancer.
Diagnosing and Treating Esophageal Cancer in Dogs
Your vet will probably be able to confirm the presence of tumors with an X-ray. CT or MRI scans can also help your vet evaluate the extent of the cancer. Your vet will need to take biopsy samples in order to confirm cancer.
If the esophageal cancer has originated in your dog's esophagus and has not yet spread, it may be possible to remove the tumors surgically. Laser surgery or photo-dynamic therapy can help reduce or eliminate esophageal tumors.
If surgery isn't an option, your vet may recommend supportive care. Chemotherapy may be used to treat esophageal cancer, but radiation therapy could be dangerous, since it could damage the delicate organs surrounding the esophagus. Your dog may need a feeding tube if tumors have blocked his esophagus.
Prognosis for Esophageal Cancer in Dogs
Esophageal cancer in dogs does not generally carry a very good prognosis. This type of cancer often spreads very quickly, and, once it has spread, it becomes much more difficult to treat.