Being told that your dog has cancer can be gut wrenching, but remember that it is not necessarily a death sentence for your dog.
Depending on the type, the size, the location, and the stage of the cancer, your dog may still be able to enjoy a good quality of life for some time yet. That is, if you and your vet work together to give him proper care and treatment.
When deciding on the best dog cancer treatment, understand that each dog is different and should be treated as such. There is no one specific cancer treatment protocol for canine cancer, whichever type of cancer it might be.
You, together with your veterinarian, should decide on a most suitable treatment plan. You may want to consider these questions when deciding on the type of cancer treatment for your dog:
- Which treatment provides the highest chance for cure?
- If a cure is impossible, which treatment is more effective in prolonging the dog’s life?
- Which treatment ensures the dog’s quality of life?
- Which treatment is the best choice for me, the dog owner? (factors to consider – costs, emotional stresses, time, level of home care, etc.)
This page looks at conventional dog cancer treatment options which include surgery, chemotherapy, and radiation.
Surgery as a Dog Cancer Treatment Option
Surgical removal of the cancer is considered by most vets to be the treatment of choice because when it works, the cancer can be completely removed from the dog’s body.
For surgery to work, the cancer should be a single tumor and the vet has to be fairly sure that the cancer has not and will not spread to surrounding tissues.
Therefore, before treatment of dog cancer by surgery, make sure that the vet has done a complete work-up so as to minimize risks and check for metastasis.
The work-up should include blood work, urinalysis, X-rays and ultrasounds.
The vet should also check the lymph nodes in the area of the cancer for enlargement. (Enlarged lymph nodes is a sign indicating that the cancer has spread to the lymph nodes.)
Side Effects
Surgery is not without side effects. Possible side effects that you should consider include:
- Pain
- Bleeding problems (during or after surgery)
- Infections of the wound
- Anesthetic accidents
Of course, not all dogs are candidates for surgery. Old dogs and those with very weakened immune systems may not survive the surgery and/or anesthesia.
Chemotherapy as a Treatment Option
Chemotherapy is the use of a medication to treat dog cancer.
Unlike chemotherapy in humans, chemotherapy in dogs is not curative.
For chemotherapy to actually cure cancer, the doses have to be very high which means the dog will have to endure extremely high levels of toxic side effects. This is unacceptable to most dog owners and is too stressful for the dog.
Chemotherapy in veterinary medicine is used to suppress canine cancer growth and to shrink some tumors, so that the cancer can go into remission.
When the cancer is in remission, it simply means that the symptoms of the cancer have been reduced, but the cancer has not disappeared completely.
The aim of chemotherapy as a dog cancer treatment is to prolong the life of the dog patient and hopefully to improve his life quality.
It is used when the cancer has spread to other sites in the body and when surgery is not possible.
Chemotherapy medications commonly come in forms that can be taken orally at home, and others are injections given by the vet.
Chemotherapy protocols usually use multiple drugs and the general strategy adopted is to given the highest, most potent dose possible within the shortest amount of time between doses.
This strategy increases the number of cancer cells killed.
Side Effects
Side effects caused by chemotherapy in dogs are usually fewer than those in humans, because the doses are lower, but some side effects can still be rather bad.
Chemotherapy drugs target cells that multiply rapidly and continually (because cancer cells multiply rapidly and continually). Therefore, healthy cells that multiply fast and continually are also affected by chemotherapy drugs.
Healthy cells that multiply fast and continually include:
- Cells that line the stomach and intestines – When they are affected by chemo drugs, side effects seen in the dog patient will be diarrhea, vomiting, and appetite loss.
- Those that produce new blood in bone marrow – When they are affected by chemo drugs, side effects seen in the dog patient will include pale gums, weakness, low immunity, bruising easily, nosebleeds and internal bleeding, blood in urine and feces.
- Cells that line the bladder – When they are affected by chemo drugs, side effects seen in the dog patient will be blood in urine, and straining to urinate.
Radiation as a Treatment Option
Radiation is another dog cancer treatment option.
Like chemotherapy, radiation is sometimes used when surgery is impossible or cannot completely remove the cancer.
In cases where the cancer is small and has not metastasized, radiation is curative.
In other cases, radiation is used as a palliative treatment to reduce pain, or to kill some (but not all) cancer cells.
Some cancers respond to radiation and some do not. Cancers that respond to radiation include:
- Lymphosarcoma
- Perianal adenocarcinoma
- Transmissible venereal tumor
- Neuroblastoma
- Plasmacytoma
Cancers that only respond temporarily or only mildly include:
- Nasal tumors
- Mast cell tumors
- Skin tumors (e.g. squamous cell carcinoma, basal cell carcinoma)
Even for cancers that do not respond well to radiation, it can still be used as a palliative treatment (e.g. radiation is often used on dogs with osteosarcoma to manage pain).
The frequency of radiation treatment depends on the purpose of the treatment.
If the purpose is to increase lifespan, radiation doses are usually given several times a day, for several weeks.
If the purpose is to shrink the tumor or reduce pain, radiation treatment frequency is less (e.g. once a week for 2-4 weeks).
Side Effects
Side effects of radiation are grouped as either “acute toxicity” or “delayed toxicity”. Acute toxicity happens soon after treatment (immediately or within days).
Common side effects include:
- Vomiting
- Lack of appetite
- Skin inflammation at radiation site (redness, swelling, hair loss, etc.)
- Damage to and inflammation of mucus membranes, such as the lining of the mouth, lungs, etc.
Delayed toxicity can take years to happen.
This may not be a problem for older dogs, but for young dogs these delayed toxicity may appear later on in their lives.
Example of this type of side effects include:
- Permanent damage to bone and ligaments, resulting in limping
- Nerve or spinal cord injury, resulting in wobbliness, difficulty getting up, etc.
- Kidney injury, resulting in frequent urination, appetite loss and weight loss
- Eye injury, resulting in cataracts, blindness
- Possibility of developing another form of cancer later in life
In Summary
Conventional dog cancer treatment options are similar to those for people. Which option to use for a dog’s cancer treatment depends on various factors, such as the type and severity of the cancer, the location of the cancer, the age of the dog, etc.
Be sure to discuss the pros and cons of all possible treatment options for your dog with your vet.