One way a dog views the world is through their sense of smell. Their nose is essential to their life experience. But it’s not a body part you might immediately worry about when you hear the word cancer. However, between 1% to 2% of all cancers in dogs are nasal tumors.
Do you know what to look for? Learn about nasal tumors in dogs and how you can give your dog the best treatment and longest life expectancy.
What Are Nasal Tumors in Dogs?
A tumor is an abnormal mass of cells that arises when cells reproduce too quickly or don’t die off when they should. Tumors can be malignant (cancerous), which means they can grow quickly, invade other tissues, and spread throughout the body. Or they can be benign, which means they usually grow slowly and don’t spread or invade other tissues.
Dr. Rachel St-Vincent is a specialist in radiation oncology at Schwarzman Animal Medical Center in New York City. She elaborates, “Nasal tumors are tumors that arise from inside of the nasal cavity, including the sinus as well as the nasopharynx. They can be benign or malignant. However, malignant tumors are more common.”
Benign nasal tumors in dogs typically come in the form of polyps, which are caused by chronic inflammation. Often seen in younger dogs, they are best treated with surgical removal. There are other types of benign tumors as well. But Dr. St-Vincent warns, “Even the benign tumors are cause for concern because some can transform into cancerous tumors, or, although benign, can be just as invasive to the surrounding tissues and cause destruction of the nose and facial structures, leading to difficulty breathing and poor quality of life, just like the more common malignant nasal tumors.”
What Causes Nasal Tumors in Dogs?
Unfortunately, research has yet to show any specific causes of nasal tumors in dogs. Chronic inflammation commonly contributes to the development of cancer, so dogs who suffer chronic allergies might be predisposed. Also, although Dr. St-Vincent says there is not enough data to support a definitive cause, there is suspicion that pollutants may play a role in nasal tumors. “Insecticides and herbicides are two pollutants that many dogs may be exposed to by sniffing grass in public parks,” she explains. “The incidence of nasal tumors in dogs is thought to be higher in urban areas, likely because of increased exposure to pollutants.”
In addition, research says nasal tumors are more common in long-nosed dogs like sighthounds. But Dr. St-Vincent says vets still see nasal tumors in some flat-faced breeds with short snouts. “The sooner these tumors are diagnosed, the better the quality of life we can maintain in your dog with treatment,” she says. “I recommend that you take all nasal symptoms seriously, especially when symptoms are asymmetric — discharge from one side only and always on the same side, for example — and especially in dogs older than 7 years of age.”
What Are the Symptoms of Nasal Tumors in Dogs?
Dog nasal tumor symptoms can vary, depending on the location of the tumor, the direction the tumor grows, and the bodily structures that are involved. Dr. St-Vincent says, “For example, although this is not a common scenario, in some cases if the tumor starts way up in the frontal sinus out of the main airways, sometimes sporadic nosebleeds can be the only symptom appreciated. Or sometimes the only symptom might be a seizure.”
What nasal tumor symptoms should you be on the lookout for? In general, anything that affects your dog’s breathing or produces nasal discharge. But be aware of all the following possible signs:
- Noisy breathing
- Nasal discharge or nosebleeds, especially if only on one side
- Difficulty breathing, increased panting, and open-mouthed breathing (which can occur when the tumor starts to obstruct the nasal passage at the back of the throat)
- Sleep apnea (when breathing stops and starts during sleep). Sleep apnea can lead to difficulty sleeping, decreased appetite, narcolepsy (drowsiness and falling asleep during the day), weakness, and lethargy.
- Anemia if the dog gets frequent nose bleeds
- Facial deformity if the tumor breaks out of the nasal cavity
- Bulging eye if the tumor extends behind the eye
- Seizures if the tumor breaks into the brain
- Bleeding in the mouth if the tumor enters the oral cavity
How Are Nasal Tumors Diagnosed?
When your veterinarian suspects your dog has a nasal tumor, they will usually start with imaging to evaluate the cause of the symptoms. Imaging can include X-rays, a CAT scan, or an MRI, as well as a rhinoscopy, which involves looking inside the nose with a small scope. If a tumor is detected, the only way to confirm whether it’s cancerous is with a biopsy, the removal of a small sample of the tumor for further examination under a microscope.
Dr. St-Vincent explains that in addition to confirming a diagnosis, it’s important to stage the patient (in other words, the vet must determine how quickly the cancer is progressing). The two most likely locations for tumor spread are the lungs and the lymph nodes in the head and neck, so the vet may perform further scans of those areas.
“In simple terms,” says Dr. St-Vincent, “this means that we go on a tumor hunt to rule out any evidence of [the] spread of the cancer elsewhere in the body. This will have a huge impact on prognosis and survival time.”
What Is the Treatment for Nasal Tumors in Dogs?
While surgery and chemotherapy have been used as the sole treatment method for canine nasal tumors, only radiation therapy, used alone or in combination with surgery or chemotherapy, has shown a significant improvement in survival time. Some medications, such as Palladia, may extend the success of nasal tumor control when coupled with radiation, and some non-steroidal anti-inflammatory drugs like Metacam. But Dr. St-Vincent explains there is no cure for nasal tumors. The goal is maintaining a good quality of life for your dog for a reasonable time frame, which is best done when the tumor is caught early.
The life expectancy for a dog with a nasal tumor depends on the tumor type, the treatment given, and how far the disease has progressed at the time of diagnosis. For example, a dog with a tumor that has already extended into the barrier separating the brain from the nasal cavity will have a much shorter tumor control time than a dog with a less invasive tumor, particularly if the tumor hasn’t broken out of the nasal cavity at all. Following radiation therapy, some dogs might gain four to six months, but most dogs will gain one to two years with good quality of life.