Rectal examination
A rectal examination allows the veterinarian to feel whether the prostate has a normal shape. Prostate tumours can cause an irregular shape of the prostate. Abnormally enlarged lymph nodes can be noticed through rectal examination or possibly through palpation of the abdominal cavity.
Blood analysis
Blood tests can indicate anaemia, an excess of white blood cells, calcium and signs of bone damage.
Urine analysis
Through urine analysis, the veterinarian can detect abnormal cells as well as indications for infection.
A positive BRAF mutation testing confirms the presence of transitional cell or prostate carcinoma. If no BRAF mutation is detected in the sample, it may be because (1) there is no cancer present, (2) there is a tumour, but it is not caused by the BRAF gene mutation, (3) the urine sample does not contain mutated cells, even though a carcinoma is present.
Imaging
Through X -rays of the lungs taken from different angles, it is possible to detect the following (if sufficiently large): lung metastases, enlargement of the lymph nodes at the level of the sternum or in rare cases metastases to the ribs or the shoulder bone. Radiographic images of the abdominal cavity can reveal an enlarged prostate, enlarged lymph nodes, and/or anomalies in surrounding bones.
Contrast matter in the urethra can also be applied to assess irregularities in the prostate (however, this technique can not differentiate between an inflammation or tumoural process).
If there is uncertainty about metastases to the bone, bone scintigraphy can be used to more accurately determine the location of possible metastases.
Ultrasound of the abdominal cavity can be useful to further assess the prostate, as well as the urethra, bladder, local lymph nodes and other organs in the abdominal cavity.
Cytology
Taking tissue samples is the gold standard for the diagnosis of prostate tumours, but a definitive diagnosis can also be obtained through the aspiration of cells and their subsequent examination (cytology).
A cytologic sample can be obtained in several ways, including ejaculation, insertion of a catheter that scrapes cells away, massage of the prostate, ultrasound-guided aspiration of cells through a needle, imprints obtained during surgery. When sampling through the skin, there is a risk that this will cause bleeding, but also cause the tumour to spread via the needle’s path. In prostate tumours, it is not required to obtain a tissue sample to determine the tumour’s grade as the impact of the grade on the prognosis is unclear.