Treating Dog Cancer

A diagnosis of cancer is devastating to a dog owner, but it is not necessarily a death sentence for the dog. Cancer is usually detected when it either forms a distinct tumor that’s quite noticeable, or it leads to organ failure and its associated symptoms. For example, a kidney tumor in a dog may cause vomiting and increased thirst, and this would be obvious to his owner.

Age is the biggest risk factor for the development of cancer in dogs, and because they are living longer these days, there is a greater chance that they may develop the condition.

Advances in human medicine are often carried over to veterinary medicine. This means that cancer can be diagnosed much earlier in the course of the disease, and new treatment options can result in a better outcome for your dog.

Let’s look at the common options available to treat cancer in dogs.

Surgery

If a cancer is easily accessible, the first thing to do is reduce its size. This means that an affected dog will undergo surgery to either completely remove the tumor, or to de-bulk the tumor as much as possible. This is easy to do with tumors such as those on the skin or mammary gland, for example. It’s also possible to surgically remove a cancerous organ such as a kidney or spleen, however the surgery is more invasive and recovery time is longer.

When a tumor is excised, a pathologist will examine the lump to look for what vets call “clean margins”. A good example of this is a mast cell tumor in the skin. If cancerous cells extend right to the edges of the tumor, it means that some dangerous cells have been left behind, and more surgery is needed to make sure more mast cell tumors don’t develop in the same area.

Theoretically, a 10mm margin of normal tissue around a tumor indicates that it has been completely removed, but it’s always worth keeping an eye on that area as a dog gets older.

Sometimes surgery isn’t particularly effective at treating a cancer, but it can make life better for the patient. That’s definitely the case with osteosarcomas. These cancers usually occur in the bones of a dog’s legs, and they are very aggressive. By the time they are diagnosed they have often spread to the lungs, and the prognosis is very poor even with treatment. Osteosarcomas are also extremely painful. Although it sounds extreme, amputation of the affected leg is very effective in easing a dog’s pain.

Surgery on its own may not be sufficient to treat a cancer, and it is often followed up with chemotherapy or radiation. Many alternative therapies can be used alongside these conventional treatment options.

Chemotherapy

When it comes to choosing how to treat a particular cancer, one of the main criteria is where the tumor is located. Some tumors can’t easily be removed by surgery. Other tumors such as lymphosarcoma can occur in many parts of the body at once, so it would be difficult, if not impossible, for surgery to remove all tumor cells.

This is where chemotherapy is particularly useful. This treatment option relies on drugs being delivered to the tumor through the bloodstream. It allows veterinarians to kill cancer cells that can’t be reached with a scalpel.

Ideally, the drugs used in chemotherapy need to specifically kill tumor cells while leaving normal cells unharmed. These drugs interfere with processes that occur in cancer cells but not in healthy cells. One feature of cancer cells is that they are rapidly dividing; many chemotherapy medications therefore specifically target rapidly dividing cells. This works well; there are several chemotherapy drugs that are proven to be effective in killing cancer cells in both humans and dogs.

The main problem with chemotherapy is that there are some healthy cells in the body which also have high rates of cell division. Examples are hair follicle cells, bone marrow cells and those cells lining the intestines. These are also affected by chemotherapy medications, and this explains the side effects of this type of treatment. Unlike people, dogs don’t seem to lose their hair with chemotherapy but if their fur is shaved, it may not grow back very well. Also, their whiskers may fall out. Damage to their bone marrow can result in reduced production of white blood cells, which means their body can’t fight off even the slightest infection. Diarrhea and vomiting can result from the effects of the drugs on their intestines.

Chemotherapeutic drugs are usually given by intravenous injection. They are extremely irritating so if there is any leakage outside the vein, there can be extensive tissue damage. The result is a large raw ulcer which may not heal.

Chemotherapy is often after surgery or in conjunction with radiation, but in some types of cancer it is very effective on its own.

Radiation

Treatment of canine cancers with radiation often results in shrinkage of the tumor, and significant pain relief. It is useful for tumors that can’t easily be removed, and also as a follow up treatment after surgery.

Radiation works by damaging a tumor cell’s genetic material, so it is no longer able to divide. As you can imagine, it can also damage healthy cells, but the effects of radiation on healthy tissue appears to be less than that of chemotherapy. This may be because radiation equipment can tightly focus the radiation beam on a small area, and minimize the amount of radiation that reaches neighboring healthy cells.

This type of cancer treatment is particularly useful for tumors that haven’t spread throughout a dog’s body. It is necessary to give a dog a general anesthetic for this treatment. That way he won’t move, and the radiation beam can be better targeted to the tumor.

Alternative therapies

Many dog owners these days are interested in alternative treatments for their four legged family members. They feel they are safer than conventional treatments, and that they are just as effective. Although these treatments are natural, they still need to be treated with respect. Even if they are non-toxic, they may still interfere with other drugs that have been prescribed for your dog. It’s important that dog owners tell their veterinarian about any other supplements or natural treatments they are planning on giving their dog to help treat his cancer.

Good nutrition will give a dog the energy to heal. Organic produce is the best food for an animal undergoing treatment for cancer, because it is less likely to have been exposed to pesticides and toxins. Similarly, if the budget allows, and the option is available, choose organic meat products to add to their diet.

Chinese Herbal Medicine may also help a dog recover from cancer. These herbs help them recuperate from tumor removal surgery, and support their body as it is exposed to follow up radiation and chemotherapy.

Acupuncture can reduce pain associated with cancer treatment and improve post-operative recovery. Homeopathy will encourage a dog’s body to heal itself.

If you’d like to investigate the benefits of alternative medicine in treating cancer in dogs, ask your vet for a referral to a member of the American Holistic Veterinary Medicine Association. Many “general practitioner” veterinarians aren’t familiar with alternative therapies, and would be happy to refer you to a colleague with more experience in this area.

Every dog’s cancer is different, and every dog will respond differently to treatment. For many cancers in dogs, treatment is available that can completely cure the disease. If a complete cure isn’t possible for your dog’s type of cancer, then treatment can prolong his life and make him a lot more comfortable.