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What are Some Signs of Cancer in Dogs?

What are Some Signs of Cancer in Dogs?

Cancer in dogs may have sounded quite like a serious diagnosis years ago, but today, thanks to the great advancements in veterinary medicine, more and more dogs are surviving, or at least, living much longer than expected. While there are several forms of cancer in dogs, it is important to point out that early diagnosis is often key to a brighter prognosis. Following are some warning signs and symptoms potentially suggesting cancer. Such signs may be either quite subtle or visibly apparent, but in any case, it is vital that they should never be ignored.

 Signs of Skin Cancer in Dogs


A sore or ulcer that appears out of the blue or that does not heal in a timely manner may be indicative of cutaneous mast cell cancer. This cancer may take different forms and is often confused for other types of benign tumors or conditions.

For this reason it is often referred to as the 'great imitator.'Any lumps or bumps in a dog's mouth should also be immediately investigated.

Just as women report to their doctors as soon as they find a lump, lumps in dogs should not be ignored. The dynamic is the same: trying to catch something in its earliest stages.

Lumps that appear to get quite large in a short amount of time raise a red flag, however, it is important to notice that even the most innocent types of lumps may as well be cancer. Most lumps are easily evaluated through a fine needle aspiration done at the vet's office.

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 Signs of Bone Cancer in Dogs

A very aggressive form of cancer mostly seen in large to giant dog breeds such as Rottweilers and Irish Wolfhounds is osteosarcoma, better known as bone cancer.

This type of cancer easily metastatizes (spreads to other organs) and often leg amputation is necessary to relieve pain and buy the dog a few more days or months. Limping, pain and unexplained fractures should not be ignored.

Signs of Spleen Cancer in Dogs 

Certain cancers are known to cause unexplained bleeding. Bleeding may be internal or external or in other words, visible or not visible. Cases of internal bleeding such as in hemangiosarcoma of the spleen, causes dogs to develop pale gums (indicative of anemia), weakness, wobbly legs and even collapse. External bleeding on the other hand is visible, for example a dog with squamous cell carcinoma of the nose may have frequent nosebleeds.

Signs of Cancer of the Digestive Tract

In general, vomiting, diarrhea, bright red blood on stools, black tarry stools, diarrhea, bloody urine, straining to urinate, can all be signs of tumors affecting the urinary or gastro-intestinal tract. The incidence of such tumors may be low but they should be ruled out if the dog cannot be diagnosed with other more common conditions.

 General Signs of Cancer in Dogs 

These are loss of interest in food, loss of weight, foul odor and unusual lethargy should be considered significant changes that should be investigated thoroughly by the vet. Because cancer can affect virtually almost any organ and therefore any part of the dog's body, it is never a bad idea to have the dog checked put promptly for any abnormal changes.

As seen, there are several signs that may potentially be indicative of cancer in dogs. It is up to the owner to recognize them and report them to their veterinarian promptly, doing so may really make a difference in the dog's prognosis.

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