Dog cancer – One of the main functions of the immune system is to identify and destroy defective tumour cells before they can reproduce themselves and the defect. In simple terms, the most common cause of canine tumour development is nothing more than a reaction failure due to the immune system not working properly.
Approximately 100 million new cells are formed in a healthy dog every day. The vast majority of these are healthy, but abnormal progeny cells are also regularly produced.
This is a normal physiological process, as the cells of the correctly functioning immune system (lymphocytes, Nk cells, etc.) recognise and destroy them, thus preventing the defective cell proliferation.
The dog cancer development process
During cell division, degenerated mutant cells are produced. The number of defective cells produced is affected by a number of factors, including toxins, radiation, birth defects and natural ageing. Age causes most of the defective cells to form. This is why tumours are more common in older dogs.
Typically, the body recognises and neutralises the defective cells that are formed in the first days/weeks/months of their growth and spontaneous healing occurs.
However, if the immune system fails to respond properly, the correct immune response is not achieved, the defective cells continue to reproduce until they grow to a size that can be detected by a doctor and we are talking about an actual tumour.
So if the immune system does not notice the defective cell and does not respond properly, a tumour can develop. By the time it’s big enough to be diagnosed as cancer, that’s hundreds of millions of abnormal cells. The tumour is then removed by surgery, radiotherapy or chemotherapy. However, the underlying cause has not yet disappeared, and the chances of the tumour growing back are high.