A bit about Cancer
Cancer is uncontrolled growth of any kind of cell in the body. There are many different ways of saying cancer e.g. tumour, neoplasia, neoplasm, carcinoma, adenoma or mass.
Cancer does not have to be a death sentence. There is a lot that can be done for patients with cancer. For many people the biggest hurdle is the word cancer itself. Very few cases occur where death is imminent. In most cases it is a matter of choosing options to improve the quality of life. A large percentage of pets with cancer can be cured or at least rendered free of their disease for a significant length of time. Euthanasia is only one of the many options. Many people do not want to put their pet through cancer treatments after seeing people suffer with cancer but most pets undergoing cancer treatment experience limited or no decline in their quality of life. We are lucky to have the options of euthanasia to prevent suffering in our pets but it doesn’t have to be our first and only choice.
The best option for cancer is to prevent it from happening. In people preventing cancer is about identifying risk factors or causes – stop smoking, sensible alcohol use, safe workplace practices and dietary recommendations have proven to decrease risk. With pets – desexing female dogs before two years prevents mammary cancer and ovarian cancer. In male dogs desexing (particularly if cryptorchid males) prevents testicular cancer. More research is needed in cancer risk factors and their prevention.
Types of cancers
Cancer can be easily classified using the type of tissue it effects and whether it is benign or malignant.
Benign cancers – grow where they are but do not spread to other sites. They can cause problems because of their position or size.
Malignant cancers – spread to other parts of the body (metastasize).
Test such as blood and urine, xrays or ultrasounds, fine needle aspirate or a biopsy may be needed to confirm the diagnosis of cancer and make an informed decision on the best way to treat your pet. These tests are very important in determining whether the cancer is benign or malignant and if malignant, whether it has already spread.
Care Options We Offer
Surgery – is the best option where possible as the cancer can be completely removed from the body. If the cancer cannot be completely removed then a biopsy is very important to obtain a diagnosis and decide the best form of treatment. Keep in mind that a chance to cut is a chance to cure. The first cut is the best – it is better for the patient to have one operation and take all the cancer with good margins than have to go through a second procedure. Often clients want to cut costs and choose to have only a minor procedure done – but this is often false economy as more extensive surgery first up could save a second operation.
Laser Surgery – laser has advantages over the scalpel for cancer surgery as it has local thermal effects, there is good sealing of small blood vessels and lymphatics and there is less chance of tumour seeding occurring. There is proven evidence of decreased local tumour recurrence. Lasers are also used for palliation where cancer is too extensive at time presented to the vet as the laser stops bleeding, gets rid of the smell, decreases pain and improves a patient’s quality of life. Laser surgery makes for a more comfortable patient and happier pet owner.
Chemotherapy – most people worry that their pet will get sick with chemotherapy. Only 20% of pets will show any sickness with chemotherapy. Only 5% will be sick enough to spend a day or more in hospital. Most animals are treated with chemotherapy with minimal impact on their quality of life. Animals do not lose all their hair (unlike people) but it does regrow more slowly so their coat may be coarser and look different than usual. Individual animals loose different amounts.
There are many different drugs used for chemotherapy. Usually combinations of drugs are used as this attacks the cancer cells in different ways and a lower dose of each drug is used which reduces toxicity. Any drug can have side effects. Your vet will give you specific information about any drugs used for your pet.
All chemotherapy drugs need to be handled with care, as they are potentially dangerous agents. If your pet is sent home with chemotherapy drugs to be given at home then it is important that you know what to do. Usually this means:
- Do not crush tablets
- Handle tablets wearing gloves
- Usually best given early in the day and best with food
- Store in a safe place
- Make sure children and pregnant women do not have access to medication.
Usually blood tests are done to see if your pet is having any side effects (such as anaemia, neutropenia, change in kidney or liver function)
Chemotherapy uses a combination of drugs in cycles to best kill cancer without serious side effects on your pet. A number of cycles are usually needed for your pet to be in remission.
Anything that comes out of your pet (faeces, urine, saliva) within 48 hours of the chemotherapy could contain traces of the chemo drug. After 48 hours there is no problem. Be aware of this and be careful – do not exchange saliva nor handle any droppings for 48 hours unless wearing gloves. We do not want to frighten you – only make you aware. Wash your hands after touching your pet (particularly within 48 hours of chemo) Normal good hygiene is all that is needed. Make sure you discuss this with your vet.
Radiation – Some cancers are responsive to radiation but not all. Radiation is usually combined with surgery and/or chemotherapy not used alone. Most animals are anesthetised for radiation therapy.
Side effects of radiation are:
- Mucositis – increased salivation and tenderness of the mouth. The patient may refuse to eat or drink and may dehydrate. This usually resolves after 2-3 weeks.
- Hair loss – some hair loss is permanent but most regrows after a few months. Often the skin is dry and can be itchy.
- Eyes – conjunctivitis, dry eye and blepharitis may occur but usually responds well to treatment with eye drops. Cataracts may occur but take years to fully develop.
The biggest disadvantage of radiation is cost.
Brachytherapy -This is the use of local treatment with radioactive isotopes. The advantage is that the cancer receives a higher dose of radiation. The main disadvantage is that surgery is needed to implant the isotope. The main use in pets is radioactive iodine used in treating thyroid cancer in cats and it is very effective.
Immunology and Biologic therapy –The role of the immune system in cancer is not well understood. Many drugs are being trialed and may be used together with other treatments or on their own. Eg piroxicam, cimetidine, interferon.
Most of these drugs are human products, many not registered for use in animals. More research may give us more options in the future.
Nutritional therapy- Some specific nutrients can be used to reduce toxicity associated with chemotherapy and radiation therapy, also to help healing after surgery. The most important thing is for your pet to eat and maintain their body weight. Aim for a diet which has good smell and good taste and has:
– Minimal amounts of simple carbohydrates (eg sugar) and more complex carbs (eg porridge)
– High in fats (especially omega 3 and coconut oil)
- Moderate amounts of highly bioavailable proteins. (eg Meat, eggs, fish, cheese)
- Consider commercially available foods Eg Puppy or kitten food, recovery diet Hills or a/d or Eukanuba maximum calorie.
It is important for your pet to eat so if they are being fussy:
- Offer favourite foods
- Try different consistencies – some animals will prefer dry rather than wet foods. – Often this is different after chemotherapy. Many drugs may leave a metallic taste in the mouth. Foods will taste different to anyone on chemotherapy.
- Warm food to just below body temperature
- Offer foods that are aromatic (smelly)
- Vitamin supplements eg nutrigel, energy or yeast based tablets or vegemite
- Gravy can be tempting or try things that are high in fat such as ice-cream, cream, peanut butter.
- Drugs eg megestrol acetate, cyproheptadine, valium may be needed.
If your pet is not eating then you may need to discuss enteral feeding with your vet.