What is it, and what do you do about it?
Few diagnoses cause as much fear as cancer. But when a loved one, such as your dog, develops any form of cancer, the first thing to do is to follow the wise words of old Douglas Adams: Don’t Panic. Cancer in dogs is serious, but once you know the diagnosis, there’s a lot you can do to reduce the risks and make life enjoyable for your dog.
What is cancer? Let me boil it down to its simplest terms. DNA is a microscopic program for building and maintaining a body. This DNA program is controlled by super-dense “tapes” of proteins called chains, and each link in the chain has a certain job in the body. One bit of DNA sets the color of the eyes, another bit of DNA decides whether the tongue likes beef or lamb better, and other bits do much more important stuff. There are chunks of DNA that tell the bones when to grow and when not to; another does the same thing for the skin, and another does the same for the brain.
Wrapping up and getting to the point, there are still other DNA sections that tell the body to dispose of unhealthy, faulty growths. When DNA is damaged or abnormal, that’s called a mutation. Mutated DNA still gives instructions, just not always good instructions. When bad DNA goes out of control, it can lead to harmful growths that aren’t disposed-of. In a nutshell, that’s cancer: Some part of the body develops a growth-related mutation and follows its instructions. Since the cancerous growth was in the DNA’s instructions, the body reasons, why should it be junked?
Cancer in dogs is just like any other cancer. It can be hereditary, or it can develop for other reasons.
What Are the Common Types of Cancer in Dogs?
Dogs can develop cancer in any part of the body, but some types of cancer are more common in dogs than others. The parts of the body most vulnerable to cancer in dogs are the lymphatic system, the mouth, the skin, the skeleton, and the breasts.
Breast Cancer in Dogs
Note that breast cancer can occur in male dogs, not just bitches. Spaying a bitch when she’s a puppy reduces the risk of breast cancer in dogs.
To inspect for breast cancer in dogs, feel around the breasts for unusual lumps. The lumps will be firm, possibly clustered, and usually near or beneath the nipple. Breast cancer in dogs is more common in the rear-most breasts. If you find these lumps, have your veterinarian do a biopsy to confirm or rule-out cancer. Caught early enough, the lumps can be removed and the cancer may not spread. In other words – removing lumps ASAP can prevent the spreading of breast cancer in dogs.
Bone Cancer in Dogs
The most common form of bone cancer in dogs is called osteosarcoma. Osteosarcoma can spread to the lungs before it’s even detected, and before that, it can lead to the bone breaking spontaneously. Naturally, the first signs the owner will notice, will be a limp. Osteosarcoma tends to affect the hind legs more often, and bone cancer in dogs is generally more common in larger breeds. The bigger the bone, the bigger the risk of bone cancer. If a large bone in your dog starts causing pain and you notice any bulging in that bone, get your dog to the vet, pronto.
Veterinary history will tell your vet most of what he or she needs to know, in order to provide an early diagnosis of bone cancer in dogs. However, an X-ray will tell your vet whether a biopsy is warranted. The biopsy is the final word. If caught early enough, the leg can be amputated to save the dog’s life, and after a short adjustment period, your dog will be fine. I’ve met one such dog, and this isn’t just lip service – the dog was perfectly fine, happy, and active after amputation. If the cancer has spread beyond the leg, chemotherapy can send it into remission.
Skin Cancer in Dogs
The most common kind of skin cancer in dogs is called a mast cell tumor. The tend to grow on the legs or the body, and they’re not caused by over-exposure to the sun. These tumors will become ulcerated – in other words, they’ll become hard, open sores. This kind of cancer is very aggressive, spreading to the internal organs with alarming speed.
Caught early, the mast cell tumors can be stopped by removing a rather large amount of flesh to ensure that the surgery “gets ahead” of the dog’s cancer. Radiation and chemotherapy may also be necessary, but so long as the internal organs are saved, your dog will probably be fine after recovery.
Mouth Cancer in Dogs
Mouth cancer in dogs is less clear-cut, as there are a variety of cancers that can strike a dog’s mouth and throat. The symptoms are similar, including pain and difficulty eating, bad breath, and blood in the saliva. Unfortunately, these signs aren’t usually caught until the disease has advanced, but regular inspections help.
This kind of cancer will spread to the jaw bones, requiring surgical removal of the infected portions of the jaw. Obviously, this makes it hard to eat. Radiation therapy usually follows, which can improve survival time, but the life expectancy of a dog with mouth cancer is usually not much more than a year.
Lymphatic Cancer in Dogs
There are four main ways for the development of lymphatic cancer in dogs. The disease can start in the gastrointestinal tract, the bone marrow, the skin or in the lymph nodes themselves. Symptoms will be different depending on where the cancer begins, but usually include vomiting, complete loss of appetite, and fever.
Lymphatic cancer in dogs is usually fatal within just a few months. Caught early enough, however, chemotherapy can send the cancer into remission. However, this isn’t a permanent cure – cancer tends to re-develop within about a year.
What Causes Cancer in Dogs?
Unfortunately, there’s no clear answer to this, which is why there’s also no real cure yet.
That being said, there are a few things that seem to contribute to the development of cancer in dogs:
- Dog Breed and Heredity. Certain breeds such as the German Shepherd and the Rottweiler seem to be at higher risk of certain kinds of cancer than others. This makes doctors believe that the breed’s core DNA may be a risk factor, which leads to the assumption that a parent with cancer may bear children who are prone as well.
- Hormones. The fact that spaying a female puppy can reduce the risk of breast cancer, leads to the belief that hormonal changes can stimulate dormant cancers into growing. This is because spaying before the first heat prevents certain hormonal processes from ever happening.
- Environmental Factors. Cancer research in humans has led to the knowledge that some chemicals will cause cancer to develop, but similar research about cancer in dogs is not quite as conclusive.
- Infections and Chronic Irritation. It’s been shown that certain viral infections that are normally fought-off and forgotten, can occasionally lead to cancer in dogs. And in humans, prolonged irritation and inflammation can lead to bone cancer.
How Can You Protect Your Dog From Cancer?
The answer is vigilant observation. For the most part, cancer can’t exactly be prevented, it can only be prevented from spreading and becoming life-threatening. There are things that increase the risk of cancer in dogs – an undescended testicle, for example, or an albino complexion. Knowledge and careful risk-reduction are truly the best we dog lovers can do.
What are the Symptoms of Cancer in Dogs?
Some of the most noticeable symptoms of cancer in dogs are: swelling, ulcers, wounds that refuse to heal, patchy loss of hair, and small clusters of nodules (bumps) on the skin.
Some more difficult-to-spot symptoms are loss of interest in food or rapid weight loss, endless thirst, diarrhea, or trouble keeping food down.
Unfortunately, our knowledge of cancer, in dogs and in humans, is not yet what it could be. We do know that the earlier you catch it, the better the life expectancy of a cancer sufferer. Some cancers can advance badly within a matter of days, so if you suspect a problem, don’t wait – visit the veterinarian ASAP.
Treating Cancer in Dogs
The only way to really “cure” cancer in dogs is to remove the cancerous tissue before it has a chance to spread. Chemotherapy and radiation treatment can sometimes send the cancer into remission, and sometimes it never returns. In all of these cases, the treatment is better than the disease. It can be expensive, but only you know the value of your dog’s life.
Chemotherapy, simply put, targets the cells responsible for sourcing the cancer, and kills them. With that done, the “main factories” causing the disease are put out of commission. There are side effects and the treatment is not 100% safe, but chemotherapy can and does lead to successes in treating cancer in dogs.
Radiation therapy basically does the same thing, but with high-energy beams.
The side effects of these treatments are very hard on the dog’s body, so it’s important to nurture him or her through recovery. Treating cancer in dogs can lead to a complete loss of appetite, so that nutrients and water need to be fed through a stomach tube so that the body can be returned to strength. Pain medication is also needed in many cases.
Sometimes the outcome of cancer in dogs, even when using the best treatments available, simply isn’t expected to be good. Treatment for life-threatening cancers can be so expensive that it’s simply impossible for most families, and in many cases the treatment will only extend life by a few months or a year. In these cases, you may be faced with only two options: home hospice, and euthanasia. Home hospice means providing all the best comfort and care that you possibly can at home, to make your dog’s final time as painless and full of love as possible. Euthanizing a dog who is only going to suffer up until he or she dies is sometimes the most humane choice.
Final Comments on Cancer in Dogs
Dogs get cancer at much higher rates than humans do. Veterinary care is improving, extending the life spans of all breeds of dogs, but this means that a single dog’s dormant cancers have more time to activate. If your dog has cancer, what you do is an extremely personal choice between the members of your household, and your vet. There’s no doubt, since you’re reading this article, that you’ll do what’s best.
Learn all about dog ownership and training, or go back to dog health issues.