The results of routine blood work (complete blood count and serum biochemistry panel) and urinalysis are typically normal in dogs with nasal adenocarcinomas. Most veterinarians will take swabbed samples of nasal discharge and submit them to a diagnostic laboratory for evaluation, including microscopic assessment of the cells in the samples (a process called cytology) and possibly for bacterial culture and sensitivity. If the dog presents with a history of spontaneous nose bleeds of unknown origin, the veterinarian probably will also conduct a coagulation profile, to see whether there are any identifiable primary disorders in the dog’s ability to form normal blood clots. This likely will include a bucal bleeding time test, which can easily be performed in-house at the local veterinary clinic.
More advanced tests include survey radiographs (X-rays) of the skull, to look for asymmetrical destruction of the nasal bones (nasal turbinates), facial bones and/or for soft tissues masses. Chest radiographs may be recommended to look for metastasis to the lungs. Much more advanced diagnostics may include computed tomography (CT scan) and/or magnetic resonance imaging (MRI), each of which provides a more sensitive assessment of the extent of abnormal tissue. A procedure called rhinoscopy can be performed to visualize the lining of the nasal sinuses and to enable the veterinarian to take tissue biopsies of any fleshy masses or other tissues that appear to be abnormal. This can be a tricky process, especially if a lot of blood or other nasal secretions are present. Biopsy samples will be sent to a diagnostic laboratory for definitive determination of the presence or absence of adenocarcinoma. Aspiration of regional lymph nodes – especially the mandibular lymph nodes – may reveal the presence and spread of primary nasal adenocarcinoma. Approximately 10% of cases have metastasized to regional lymph nodes at the time a diagnosis of canine nasal carcinoma is made.
There is no one diagnostic protocol for nasal adenocarcinoma. The veterinarian will adopt an appropriate diagnostic plan based on how the particular animal presents. However, adenocarcinoma is not particularly difficult to diagnose, if the owner is willing to go through the steps necessary to reach a definitive diagnosis.