Effective cancer treatment begins with an accurate diagnosis. Cancer diagnostics should answer three questions: what type of cancer we are dealing with, how advanced it is, and what the patient’s general condition is. Only then can treatment be planned that suits the individual animal – and its owner’s circumstances.
When should you see a veterinary oncologist?
It is worth booking an oncology consultation both when a cancer has already been diagnosed and when the referring veterinarian only suspects one. Warning signs include:
- a lump or skin lesion that persists for longer than 4 weeks or grows quickly,
- enlarged lymph nodes (e.g. under the jaw, in front of the shoulders, behind the knee),
- weight loss and loss of muscle mass without an obvious cause, reduced appetite,
- chronic vomiting or diarrhoea,
- lameness, or swelling of a bone or toe that does not resolve with treatment,
- nosebleeds, coughing, breathlessness, difficulty swallowing,
- abnormal blood test results – e.g. raised calcium, anaemia, an abnormal platelet count.
You can read more about less obvious signs in the section on paraneoplastic syndromes.
Which tests are used to diagnose cancer?
Fine-needle aspiration (cytology)
Cells are collected from the lesion with a thin needle. The test is quick, usually does not require anaesthesia, and in many cases allows a preliminary diagnosis – for example, distinguishing a lipoma from a mast cell tumour or confirming lymphoma in an enlarged lymph node.
Tissue biopsy and histopathology
Examination of a tissue sample or of the whole removed tumour. Histopathology establishes the definitive diagnosis and the grade of the cancer (known as grading), and shows whether the tumour was removed with an adequate margin of healthy tissue.
Blood tests
A complete blood count and blood biochemistry assess the patient’s general condition and the function of the internal organs. They also help detect changes that accompany cancer and are essential before every chemotherapy treatment.
Diagnostic imaging
Abdominal ultrasound, chest X-rays (to look for lung metastases) and, in selected cases, computed tomography. CT is particularly useful when planning extensive surgery and radiotherapy. This was the case for Nuta, whose CT scan helped plan the removal of a tumour of the ribs.
Specialist tests
Some cancers require additional tests – for example, immunophenotyping in lymphomas (determining whether the cancer arises from B or T lymphocytes) or testing for c-KIT gene mutations in mast cell tumours. The results influence the choice of treatment and the prognosis – examples are the stories of Teddy and Mruczek.
Staging the disease
Once the type of cancer has been identified, its stage is determined: the size and invasiveness of the tumour, involvement of nearby lymph nodes, and the presence of distant metastases. The prognosis and the choice of treatment depend on this assessment – chemotherapy, radiotherapy, electrochemotherapy, surgery, or metronomic and palliative therapy – or a combination of these.
How to prepare for the first consultation
- Medical records: blood test results, ultrasound and X-ray reports, cytology or histopathology results, and the history of treatment so far.
- A list of medicines given now and recently (including supplements).
- Photos of the lesion taken over time – they help assess how quickly it is growing.
- Keeping your pet calm: if your animal is very stressed by visits (especially cats), ask beforehand about calming medication that can be given at home.
You will find answers to other questions before your visit in the FAQ.