Oncology : Chemotherapy –Radiotherapy –Curietherapy
Canine, feline and equine cancers
At Oncovet, we treat canine, feline and equine cancers using four different technologies: surgery, radiotherapy, chemotherapy and curietherapy. Oncovet offers a wide range of modern treatments indicated for the treatment of pathologies such as :
- Lymphomas, carcinomas, sarcomas and melanomas in dogs and cats
- Skin cancers, bone cancers, bladder cancer, liver cancer, mammary cancer, jaw cancer, prostate cancer, lymph node cancer, lung cancer, in dogs and cats
- Tumours in the liver, skin, bones, mammaries, jaws, brain, intestines, lungs or in the spleen in dogs and cats
In certain cases, and in full consultation with the veterinarian, your pet may benefit from new treatments as part of a clinical study, for which the treatment fees are free of charge.
Chemotherapy for dogs and cats
Cytotoxic chemotherapy is a general method of treatment which destroys cancerous cells or prevents them from multiplying. It allows the treatment of numerous cancers in cats and dogs, such as :
- lymphomas, leukaemias, multiple myelomas, for which chemotherapy is most frequently used on its own, as these tumours are very sensitive to chemotherapy.
- certain aggressive tumours with a high risk of metastasis, such as tumours of the bone (osteosarcomas), the spleen (hemangiosarcomas), or other organs (lungs, bladder, mammary tissue...) as a complement to the local treatment of the tumour (surgery, radiotherapy).
- tumours of the head and the neck, usually alongside radiotherapy.
- inoperable tumours or cancer that has metastised, as part of palliative care.inoperable tumours or cancer that has metastised, as part of palliative care.
Unlike surgery or radiotherapy, which aims to destroy a localised tumour, chemotherapy allows tumour cells to be destroyed wherever they are located.
The principle of cytotoxic chemotherapy is to administer a substance that is disseminated in the body of the dog or cat patient through the blood and kills tumour cells, sparing healthy cells. Most of these molecules only destroy cells that tend to multiply very rapidly (tumour cells).
Chemotherapy is therefore well suited to the treatment of tumours present in many parts of the body (in the case of tumours with metastases or lymphomas) or for localised but inoperable tumours.
What is the process for chemotherapy in dogs and cats ?
Most chemotherapy is carried out by administering repeated injections at precisely timed intervals. Chemotherapy is usually administered intravenously, but may also be administered via through oral, subcutaneous, intramuscular, intraarterial, intertumoral (injection directly into the tumour) or intracavitary (injection directly into the thoracic or abdominal cavity) methods. Before each chemotherapy treatment, a blood test is carried out in order to check the quantity and quality of your animal’s blood cells.
In effect, most of these chemotherapy molecules will cause a temporary reduction in the number of some of these cells (mainly in the white blood cells and platelets). It is therefore essential to check that the animal is strong enough for the treatment, particularly when several treatments are carried out in a short period of time.
For some molecules, other examinations (kidney or liver, cardiac ultrasound ...) are necessary before each treatment, to be sure that the patient can withstandthe planned treatment. Depending on the case, a greater or smaller number of sessions may be necessary with a variable frequency (rarely more than one session per week).
Why admit your dog or cat to hospital ?
The treatment must be administered under strict conditions, with close monitoring for the dogs and cats being treated using chemotherapy. Since 2009, French legislation has stipulated that for all chemotherapy sessions, a minimum stay in hospital of 24 hours is required in theclinic where the treatment has taken place. This short-term hospitalisation is therefore mandatory. We are aware that such a separation is painful for you, but please be assured that the comfort and security of your animal are our priority.
Are there any side effects ?
The side effects of cytotoxic chemotherapy do not occur frequently in veterinary medicine as long as all the necessary precautions are taken and they are not at all comparable to the side effects reportedin human medicine. A temporary and reversible reduction in the number of white blood cells may sometimes cause fever, fatigue or an inability to fight infection. Digestive side effects (loss of appetite, some diarrhea or vomiting) may also be observed, but effective treatments to prevent or cure them are available. In certain breeds (particularly poodles or bichons), some hair loss may occur.
These side effects can be observed in approximately 30% of dogs and cats treated using cytotoxic chemotherapy, and usually the symptoms are low-intensity and temporary.
More acute side effects that may require temporary hospitalisation are reported in 5% of cases. The quality of life of the animals treated using cytotoxic chemotherapy is therefore often normal and similar to those reported by owners before the diagnosis of cancer.
In some cases, you will be offered metronomic chemotherapy. This involves the daily at-home oral administration of small doses of anti-cancer medication, intended to stabilise the illness. There is no hospital stay, but the owner is required tobe very precise and rigorous.
Chemotherapy is essential for the treatment of many cancers. If proper cooperation is established between the oncologist, the treating veterinarian and the owner, the chemotherapy canbe carried out with optimal effectiveness and quality of life for the animal receiving the treatment.
Do not hesitate to ask as many questions as necessary or to let us know of any change in the condition of your pet: this information is useful to us to optimise its treatment.
Electrochemotherapy is a technique which combines intravenous administration or administration directly into the tumour (intratumoral injection) of a chemotherapy agent and the application of electrical impulses through specific electrodes in order to assist the anti-cancer agent to penetrate into the tumour cells. This treatment is carried out under a short general anaesthetic. Usually, 2 sessions are carried out atintervals of 7 to 14 days, with a stay in hospital of 24 hours for each session.
Electrochemotherapy largely applies to the treatment of non-operable cutaneous tumours, or to complement surgery if it has not been possible to shrink the tumour entirely. For example, some mastocytomas, epidermal carcinomas and cancers of the breast or perineal areas may be treated in this way.
Other medical anti-cancer treatments
Targeted therapies are anti-cancer treatments which have recently become available on the veterinary market. Theyare administered orally, in tablet form, by the owner at home, with no hospitalisation required for the animal being treated. They aim to block, in a targeted manner, certain receptors situated on the surface of or inside cancerous cells to prevent them from spreading and multiplying. As with any medical treatment, targeted therapies may take action both on the original tumour and on any metastases.
The targeted treatments include inhibitors for receptor tyrosine kinases, which are generally used in the treatment of certain skin tumours (mastocytomes), as well as in the treatment of other types of cancer (tumours of the thyroid, the nasal cavities, the anal glands...). The side effects are similar to those observed in classic chemotherapy in most cases, predominantly involving digestive problems. Although the treatment is administered outside the clinic, regular checks are necessary in order to ensure the effectiveness of the treatment and that it is being well tolerated.
Immunotherapy is a course of treatment which aims to interact with the immune system of the patient, to reinforce its own immune defences against cancer: this is referred to as anti-tumour immunity. Immunotherapy as a technique is still at an early stage in veterinary medicine, and its position compared with other more conventional treatments remains uncertain. Nonetheless, immunotherapyis never used as the only treatment for cancer, and its main objective is to increase the chances of remission or cure in the long term.
We now have immunotherapy protocols for feline fibrosarcomas, and multicentric lymphomas and melanomas of the oral cavity in dogs. They can be discussed on a case by case basis, and other indications will probably join this list in the years to come. These immunotherapy protocols generally consist of administering injections at regular time intervals (as with vaccinations), in veterinary clinics during short visits.