Clinical signs that could indicate an underlying cancerous condition.
By FidoCure's Dorothy Jackson Girimonte, DVM, DACVIM (Oncology), CVA

There are a variety of clinical signs that could indicate an underlying cancerous condition. None of these are specific to cancer but instead indicate that our fur kids should be evaluated by a veterinarian as soon as possible.

Gastrointestinal Signs (Digestive Tract)
There are several signs that indicate gastrointestinal upset, including decreased appetite or not eating at all, vomiting, and diarrhea. These are vague and could be due to a variety of diseases, including infection, inflammation, dietary indiscretion, foreign body, etc. Bloodwork and/or an abdominal ultrasound can often be helpful in differentiating between these.

Other signs could include scooting excessively, straining to defecate, or ribbon-like stools. This could indicate enlarged anal glands or a mass arising near the colon or rectum. The underlying cause can often be determined by a thorough physical examination, including a rectal exam.

Respiratory Signs
There are a number of signs to monitor for associated with the lungs and airways: new and/or persistent cough, exercise intolerance, restlessness, and gums that are blue/pale in color. The cough may start out as occurring only after strenuous exercise or be intermittent.

It can then progress to one that is persistent throughout the day/night and prevent these patients from laying down or getting comfortable in their usual spots. If there is enough underlying inflammation, these patients may also cough up fluid that is red in color or contain blood clots.

Other signs could be a loss of interest in playing/running or tiring more quickly and easily than normal. If there is not enough oxygen circulating throughout the body, the gums may be bluish instead of a nice, healthy pink. Sometimes, there is more abdominal effort when breathing, as these patients have to work harder. Any patient that seems to be in distress should be evaluated by a veterinarian immediately.

New “Lumps or Bumps”
Some cancers can arise as a new mass somewhere along the body. Skin tumors often start out as a single mass. This group of tumors can include anything from benign, fatty tumors to more aggressive mast cell tumors and sarcomas. They can be soft and freely movable or more firm and fixed to the underlying tissue (i.e. hard to move around).

Lymphoma, one of the more common cancers seen in dogs and cats, arises from the lymphatic system (part of the immune system). In dogs, it often affects the lymph nodes first. On examination, this is detected as multiple masses along the body that appear around the same time. These lymph nodes are more commonly found under the jaw, in front of the shoulder blades, and along the hind limbs behind their knees. The lymph nodes are firm but often not painful.

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Head/Neck Clinical Signs
If there is a mass within the mouth (benign or malignant), it can cause signs related to eating and drinking. Sometimes our fur kids will drop food or appear to eat on one side of their mouth. If the mass bleeds intermittently, you may notice drops of blood in the water bowl. For those that receive both dry and canned food, they may seem more interested in their canned food as the softer texture is easier and less painful to eat. They may also stop chewing on any hard bones or toys.

If the mass affects more of the nasal cavity, you may notice an increase in sneezing. They also may sneeze out a bloody fluid or small clots of blood. Our fur kids may develop a nasal discharge from one or both of the nares (nostrils), depending on the extent of the mass. You may also see swelling along the bridge of the nose or around the eyes.

Again, the above-mentioned clinical signs are not unique to cancer itself. These can also be seen with dental disease, upper respiratory infections, and allergies. If you notice these signs, please have your fur kid evaluated by their veterinarian.

Other Signs
There are other clinical signs that warrant an evaluation to determine if there is an underlying cancerous process. Your fur kid may suddenly develop a lameness in one of their limbs or hold up one of their limbs altogether. Sometimes a swelling may be noticed, moreso seen in the front limbs.

Your fur kid may have a change in their urinary habits that would justify further evaluation to differentiate between an infection or a possible mass. These clinical signs could include urinating more frequently, having accidents in the house, straining to urinate, and bloody urine.

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