What Is Ceruminous Gland Adenocarcinoma in Dogs?
Ceruminous gland adenocarcinoma is a rare malignant tumor that originates from the sweat glands located in the external auditory canal of a dog’s ear. The term “cerumen” refers to ear wax, which is produced by ceruminous glands. This type of cancer is exclusive to a dog’s ears and the surrounding structures, as ceruminous glands are only present in the ear canal.
Ceruminous gland adenocarcinomas typically begin growing within the ear canal and can be distinguished from benign polyps by their appearance, although not always. Generally, adenocarcinomas have irregular shapes and tend to ulcerate and bleed easily, whereas benign growths are smooth. This differentiation helps in identifying and diagnosing the condition accurately.
Symptoms
Symptoms of ceruminous gland adenocarcinoma closely resemble those of a typical ear infection, but they typically affect only one ear. Common indicators include:
- Scratching of the affected ear
- Shaking of the head
- Discharge accompanied by a foul odor from the ear
- Head tilt
- Signs of discomfort or pain
Notably, the volume of ear discharge associated with this tumor is often greater than that of a regular ear infection, and the discharge may contain blood. In cases where the tumor is sizable or affects deep ear structures, your dog may exhibit additional signs such as impaired balance, circling while walking, dizziness, and falling to one side. These symptoms collectively indicate the potential presence of ceruminous gland adenocarcinoma in dogs.
Causes
The exact cause of ceruminous gland adenocarcinoma remains unknown. However, there is suspicion that chronic inflammation of the ceruminous glands, often stemming from chronic or recurrent ear infections, may be a contributing factor.
Prompt treatment of ear infections is crucial as it may help mitigate the risk of developing adenocarcinoma. Timely treatment not only alleviates discomfort but also reduces the chances of complications such as ruptured eardrums and hearing loss. Cocker Spaniels are at a higher risk of developing ceruminous gland adenocarcinoma compared to other breeds, possibly due to their predisposition to chronic ear infections.
Although ceruminous gland adenocarcinoma is the most common tumor affecting the ear canal in dogs, it remains a rare occurrence overall. Interestingly, it is more prevalent in cats.
Diagnosis
To diagnose ceruminous gland adenocarcinoma in dogs, veterinarians employ several diagnostic methods. Initially, the veterinarian conducts an examination of the affected ear using an otoscope, a tool that illuminates the ear canal for visual inspection. In some cases, the tumor may be visible and diagnosed during the initial veterinary examination.
Depending on the condition of the dog and the preliminary diagnosis, the veterinarian might recommend a sedated ear examination. During this procedure, the dog receives sedative medications to induce unconsciousness, allowing for thorough ear flushing to remove debris. Subsequently, a small camera is inserted into the ear for a more detailed examination.
Once the mass is identified, further diagnostic steps may include a CT scan or a biopsy to assess the full extent of the tumor. During a biopsy, a sample of the tumor is carefully extracted by the veterinarian for examination by a veterinary pathologist. This analysis helps determine whether the tumor is benign (noncancerous) or malignant (cancerous), aiding in treatment planning and prognosis assessment.
Treatment
The primary treatment option for ceruminous gland adenocarcinoma in dogs that offers a favorable prognosis is surgery. Before proceeding with the surgical removal of the cancerous mass, the veterinarian conducts blood tests and lung x-rays to detect any signs of metastatic disease (spread of cancer). Lymph node samples near the affected ear may also be taken to assess for metastasis, a process known as staging, which helps determine the suitability of surgery and the potential for a successful outcome.
The standard treatment for ceruminous gland adenocarcinoma involves surgical intervention, commonly performed through a procedure known as total ear canal ablation (TECA). TECA entails the complete removal of the ear canal, its associated structures, and thorough cleaning of the inner ear. As a result, the dog may experience deafness in the affected ear post-surgery, as the auditory structures of the external and middle ear are typically removed, and sometimes even the inner ear.
For tumors confined within the ear canal, TECA often proves curative. However, if the tumor extends to the skull bones, additional treatment such as radiation therapy or chemotherapy may be necessary based on the diagnostic findings.
Following the surgery, the veterinarian communicates the results of the pathologist’s report to the owner. The pathologist examines the excised mass to determine the cancer type and assess whether complete removal was achieved, providing clarity on the treatment outcome. Regular follow-ups with the veterinarian are essential for monitoring the dog’s recovery and overall health status.
Living and Management
Following TECA surgery, your dog will likely require medications and rest for several weeks to aid in recovery. It’s crucial to allow sufficient time for your dog to recuperate from the significant surgical procedure and to adapt to deafness on the affected side of the face. Most dogs adjust well to these changes, and your veterinarian can offer guidance on facilitating your dog’s transition to its altered environment.
Adherence to the prescribed medication regimen is essential to promote proper healing. If you have any concerns about your dog’s behavior or symptoms during the initial recovery period, promptly contact your veterinarian for assistance. Additionally, attending follow-up appointments as recommended by your veterinarian is vital to ensure a prompt and healthy recovery for your dog. These visits allow for ongoing monitoring of your dog’s progress and the timely addressing of any emerging issues.
Ceruminous Gland Adenocarcinoma in Dogs FAQs
What function does the ceruminous gland serve?
Ceruminous glands produce cerumen, commonly known as ear wax. Ear wax plays a vital role in safeguarding the deeper structures of the ear and preventing bacterial and fungal infections. Occasionally, overproduction of ear wax by the ceruminous glands can lead to increased susceptibility to infection.
Is adenocarcinoma of the ear fatal to dogs?
Untreated adenocarcinoma of the ear can be fatal for dogs, with a short survival time if left unaddressed. However, with aggressive therapy such as surgery, dogs can live an average of five additional years.
Do dogs lose hearing in the ear that undergoes surgery?
Dogs that undergo a TECA procedure lose hearing on the operated side. The surgery involves the removal of auditory structures, resulting in deafness on that side. Dogs typically adapt well to their altered hearing status, particularly since the cancer likely impacted their hearing prior to surgery, making the adjustment less significant for them.