Tumor of the Throat in Dogs

A tumor in the throat in dogs is an uncommon occurrence. However, it does happen and can have serious consequences for the health of your pet. A growth in the throat area can be benign, but may also be malignant. In some instances, a tumor in the throat will arise because of a malignancy elsewhere in the body. Surgery is usually the standard method of removal, along with treatment for the underlying cause if needed.

The throat can be the location of many types of tumors in canines, with two examples being tonsillar and tracheal. Often masses of aggressive nature, malignancy is common, and detection at an early stage will offer the best prognosis.

Signs can be different from one tumor to another, and can vary in severity due to the location and size of the mass. If you see your furry family member showing any of the signs listed below, schedule an appointment with your veterinarian.

• Weakness
• Regurgitation of undigested food or blood
• Vomiting after eating
• Difficulty swallowing (dysphagia)
• Pain when swallowing
• Irritation of the throat
• Change in bark tone
• Difficulty breathing (dyspnea)
• Respiratory distress or noisy breathing
• Bluish colored mucus membranes (cyanosis)
• Coughing
• Lethargy
• Depression
• Weight loss
• Excessive salivation and drooling (ptyalism)
• Odorous breath (halitosis)
• Swelling in neck or throat area
• Difficulty participating in exercise, or lack of interest in usual activities
• Possible changes in drinking and urinary habits

Types

The list for types of tumors of the throat in dogs is very extensive. Some of the growths that can be diagnosed are found below.

• Laryngeal tumor
• These are found on the wall of the larynx and can cause a respiratory obstruction
• Laryngeal oncocytomas occur most often with young dogs, but are fortunately minimally invasive
• Chondrosarcomas of the larynx are mostly of the malignant sort and develop in connective tissue of the larynx
• Squamous cell carcinoma of the larynx can form in the upper, middle or lower area
• Tracheal tumor
• Chondrosarcomas of the trachea often spread to regional lymph nodes
• Squamous cell carcinoma of the trachea will invade other regions of the body like the esophagus, thymus and lymph nodes of the chest
• Tonsillar tumor
• These tumors are highly metastatic and will metastasize early in their development to organs and regional lymph nodes
• Squamous cell carcinoma tumors can invade the bone and are highly aggressive
• Esophageal tumor
• Squamous cell carcinoma of the esophagus is often found in German Shepherds, Basset Hounds, collies, Keeshonds, and Schnauzers
• Studies show an infestation of parasitic worms called spirocerca lupi can cause osteosarcoma of the esophagus
• Thyroid tumor
• This type of mass can appear in the esophageal area
• They are usually large and invasive
• Golden Retrievers, Labrador Retrievers, Boxers and Beagles are breed predisposed
• Mast cell tumor
• The average age for dogs with this growth are nine years of age
• Boxers, Boston Terriers, Beagles, Bulldogs, and Schnauzers are presented often in studies
• The location is found all over the body, but in the throat, it is usually on the larynx

It should be noted that the closer a tumor is to the lymph nodes of the throat, the more chance there is that it will metastasize.

The definitive cause for tumors of the benign or malignant type is an ongoing study for scientists and researchers; a cure is hopefully within reach. Reasons that your canine companion may have developed a mass in the throat are listed below.

• Genetics
• Infection
• Invasion of cancerous cells from elsewhere in the body
• Cell malformation
• Damaged cells being replaced by cancerous cells
• Age
• Environmental pollutants
• Chronic inflammation

The variety of tumors that can present themselves in the throat of our beloved canines is extensive. Because of this fact, the diagnosis procedure could be of an extensive nature as well.

Learning that your pet has a tumor can be a distressing time. Remember to allow your veterinarian to use her expertise in the diagnostic process; her goal is to provide the utmost care to your canine family member. Methods that will be considered as part of the evaluation and investigation could include the following.

• A complete blood count, chemical profile, and urinalysis are usual starting points
• Radiographs of the trachea or esophagus could be done if the tumor is suspected to be located there
• A chest and neck radiograph may be done
• Fine needle aspirate cytology could be needed to check the lymph nodes for cancer cells
• An endoscopy or bronchoscopy may be done, depending on where the tumor is, and whether the procedure would be risky
• A biopsy might determine if cell death or inflammation are present
• A thyroid function test (blood test T4) will measure the level of thyroid hormones in the blood
• Nuclear scintigraphy may be suggested (radioactive material is injected to locate cancer, and it’s spread)
• Computed tomography (CT) scan or magnetic resonance imaging (MRI) can evaluate the invasion of cancer into bone, lymph nodes, and lungs, or the nasal, oral and ocular areas

Many of these diagnostic tests will require your dog to be sedated or put under general anesthesia. He will be carefully monitored throughout.

Your veterinarian will discuss which method of treatment will offer the best prognosis for your family pet. The options will always depend on the health condition of your pet when the tumor is discovered, his age, how comfortable he is in regards to airway restriction, and his general sense of well-being. It should be noted here that treatment is not always an option. If a tumor is malignant and cancer has spread aggressively, the best solution for the sake of your dog may be palliative care or euthanasia.

In the case of a tumor that is benign, or that may be malignant but can be completely excised (for example if it is easily reached by a surgeon), surgery will be the choice of action. There are many types of surgical intervention that your veterinary team will discuss with you. For example, a tumor in the larynx may involve a laryngectomy, and a tracheal tumor could require a removal and resectioning of part of the trachea. In most surgical cases, chemotherapy and radiation will follow.

Thyroid tumors can present a different scenario because medical control of the thyroidism (whether hypo or hyper) needs to be also managed. Typically, most thyroid tumors are found to be malignant. External beam radiation is one method used to destroy thyroid tumors.

As the owner of a dog who has had a throat tumor, you should be aware that recurrence is possible, even after surgery, chemotherapy and radiation. More than that, the knowledge that the longevity of your much-loved dog’s life may not be extended that much further even with treatment, should be a consideration. Do not hesitate to ask your veterinarian for an honest, heart to heart recommendation of what is best for your pet.

If you are in the fortunate circumstance that a full recovery is expected, you should be prepared to spend the time needed after the surgery to nurse your pet back to health. He will benefit greatly from a quiet area in which to rest and sleep. Your veterinary team will provide information for the home care such as special dietary requirements necessary after throat surgery, and instruction on the administration of pain relief and antibiotics as prescribed. Follow-up radiographs may be scheduled at 2 to 4-month intervals for quite some time as complete excision of the tumor is often impossible, and the chance of recurrence is always present.