The Symptoms of Canine Cancer

Just as in humans, cancer is a common dog disease. As a dog grows older, its risk of getting cancer increases. No one knows what causes cancer, but it is a deadly disease, and you should know the symptoms to look for to catch it early.

Cancer in dogs affects the skin, bone, and other organs. Some are slow growing and some progress very rapidly. There are effective treatments for many types of cancers, and research is regularly identifying new ones.  Early diagnosis has a significant effect on the success of treatment.

What to look for:

Loss Of Appetite

One of the common signs of canine cancer is that the dog will lose its appetite. You will notice that the dog does not eat as it used to, and this will often result in weight loss.

Chronic Lumps And Sores

The dog will develop swelling and sores that do not heal. Some of the swelling and sores will be in the mouth, making the teeth look unhealthy and making eating and swallowing difficult.


Another sign of canine cancer is tiredness and lethargy. This may make it difficult for the dog to move, and it may sleep a lot.

Enlarged Abdomen

In certain cancers, the dog’s abdomen may become enlarged, resembling a pot belly in humans.

Bloody Stools and Urine

Another sign of canine cancer is difficulty urinating and defecating, which may be accompanied by blood in the urine and stools.

Types of Canine Cancer

There are many different types of canine cancer.  And it seems that dogs contract the same kinds of cancer that humans do.   Some of the most common canine cancers are:

1. Bone Cancer (see below)

2. Mouth Cancer

3. Mast Cell Tumor Cancer

4. Prostate Cancer

5. Liver Cancer

6. Lung Cancer

7. Pancreatic Cancer

These are just a few of the types of cancer that a dog can develop. As you can see, all of them except number 3 on the list has a human counterpart.

A mast cell tumor cancer is the tumor develops on the outside of the dog’s body. Sometimes they go unnoticed because they develop under the dog’s fur. So you have to be extra vigilant when paying attention to your dog’s care.   As with all cancer, early detection is the key to survival.

Other Forms of Canine Cancer include:

8.  Skin tumors. Skin tumors in dogs are rather common. Melanomas, lipomas, basal cell tumors and mast cell tumors are the most often diagnosed. All skin tumors – lumps or masses of any sort – should be examined by your veterinarian.

9.  Lymphoma. This form of cancer is common in dogs. Lymphoma can affect the digestive system, resulting in lethargy, vomiting and diarrhea. It can also affect the liver  resulting in lethargy, vomiting and a yellow tinge to the gums and skin. Lymphoma can also affect the chest, causing coughing and difficulty breathing.

10. Mammary gland tumors. These tumors are more common in the older female dog that has not been spayed. About 50 percent of all tumors in dogs are mammary gland tumors. Of those, about ½ are malignant. Typically, a lump is felt in the breast tissue. Although they are most common in intact dogs, they can also occur in spayed dogs.

11. Abdominal tumors. Abdominal tumors are common, but it is difficult to make an early diagnosis. Some examples include hemangiosarcoma, mast cell tumors, lymphoma and prostate cancer. You should be aware of any weight loss, weakness, pale gums, protracted vomiting, continual diarrhea, and/or abdominal enlargement and see your veterinarian if these signs occur.

12. Testicular tumors. This type of tumor is the second most common tumor of intact male dogs. Signs are usually one large testicle and one normal sized testicle. If malignant, the cancer can spread throughout the body, resulting in weakness, lack of appetite and weight loss.

Different Types of Canine Bone Cancer

There are several different types of canine bone cancer. They are as follows:

Primary bone cancer – This is bone cancer that originates in the bone.

Metastatic bone cancer – This is bone cancer that has originated somewhere else in the body, but has traveled to your dogs bones via the bloodstream.

There are different types of primary bone tumors associated with primary bone cancer also. They are:

Osteosarcoma – This type of bone tumor is found mainly in the legs, shoulders, wrist and knees. It is very malignant and is very aggressive in dogs. Osteosarcoma develops inside the bone and grows out. Eventually destroying the bone from within, replacing regular bone with tumor bone. This tumorous bone is very fragile and can break with little or no effort. This pathologic fracture will not heal. Forcing the owner to choose between euthenasia or amputation of their dog. Early detection and intervention is encouraged with this type of bone tumor because of the chances that the cancer has already metastasized, or traveled.Chondrosarcoma – This is bone cancer of the cartillage. This type of bone tumor is very rare. it also can travel to other parts of the body, most likely the lungs. Resulting in lung cancer.

Fibrosarcoma – This is a bone tumor that can come from the connective tissues of your dogs bones. This type of bone cancer can spread to other parts of the skin and is less likely to spread to other organs. It is most common in older dogs.

Hemangiosarcoma – This type of bone cancer is fed by your dogs blood. Hemangiosarcoma’s start in the blood vessels, and can start anywhere in the body. They frequently spread to your dogs brain or spleen. Because of the nature of this type of bone tumor, prognosis is not good. One of the leading causes of death with hemangiosarcoma is a rupturing of the blood-filled tumor.

Symptoms of Canine Bone Cancer

As you can see from above, canine bone cancer is very serious! That’s why it is very important to try to catch the disease in its earliest stages. Once canine bone cancer is discovered, veterinarians assume that it has spread to other parts of your dogs body. This will later be confirmed through a battery of intensive tests. But you can do your best to avoid these by being ever vigilant and keeping a close eye on your dog. Making sure that if anything is out of the ordinary, it is reported to your local vet immediately!Some of the symptoms of canine bone cancer are:

Lameness – Meaning that your dog can no longer place his/her weight on that particular limb. They might be seen limping or licking the paw of the limb that is affected.

Loss of appetite – The loss of appetite in ANY dog is a cause for concern. It might not necessarily be cancer, but it is something to be worried about!

Weight loss – A direct result of loss of appetite.

Whimpering – He/she may be whimpering for no apparent reason. Something to check out, definitely!

Insomnia – Again, not necessarily cancer but, a sure sign that something is wrong because normally dogs will sleep ANYWHERE!

 In conclusion, dog owners should always be on the lookout for these possible canine cancer symptoms and the owner should be proactive in the treatment thereof.

  •           Any lump or mass that appears to be increasing in size
  • Any sore that does not heal
  • Change in bowel or bladder habits
  • Difficulty urinating or defecating
  • Unexplained bleeding or discharge from any body opening
  • Loss of appetite
  • Weight loss
  • Difficulty breathing
  • Persistent lameness or stiffness
  • Offensive odor
  • Difficulty eating or swallowing

If you notice any of the symptoms, consult with your veterinarian. If found early, most of these cancers can be cured with surgery, chemotherapy, radiation therapy, or a combination of the three, and early diagnosis will aid your veterinarian in delivering the best care possible.

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Keywords: Canine Cancer, Dog Cancer